ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

You have 0 saved results.
Mark results and click the "Add To Watchlist" link in order to add them to this list.
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (1,329)
  • Springer  (1,329)
  • 1990-1994  (1,329)
  • 1950-1954
  • 1993  (1,329)
  • Electrical Engineering, Measurement and Control Technology  (1,329)
Collection
  • Articles  (1,329)
Years
  • 1990-1994  (1,329)
  • 1950-1954
Year
Journal
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 153-154 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Once designed, implementation of an optimal mean-square binary morphological filter is extremely fast, especially when the erosions are implemented on a suitable parallel processor. On the other hand, optimal filter design involes a computationally burdensome search procedure that can, in practice, be intractable. The present paper provides an algorithm for filter design that is based on the relationship between the optimal morphological filter and the conditional expectation. The algorithm proceeds by changing the conditional expectation into a morphological filter while at the same time increasing the mean-square error by a minimal amount. It does so by switching observations between the 1-set and the 0-set of the conditional expectation. The switching algorithm is extremely efficient in many noise environments, and therefore provides a filter design that can be useful for online structuring-element updating. Owing to the relationship between stack and morphological filters, the algorithm is at once useful for finding optimal binary stack filters.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 263-278 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract New characteristics of feedback neural networks are studied. We discuss in detail the question of updating of neurons given incomplete information about the state of the neural network. We show how the mechanism of self-indexing for such updating provides better results than assigning ‘don't know’ values to the missing parts of the state vector. Issues related to the choice of the neural model for a feedback network are also considered. Properties of a new complex valued neuron model that generalizes McCulloch-Pitts neurons are examined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 391-407 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper deals with chained eigenstructure assignment for strongly controllable singular systems of the form Êx (t)=Â x(t)+B u(t) with state feedback control of the formu(t)=Kx(t)+w(t). The development of our method depends crucially on the properties of standard form singular systems. The closed-loop system will satisfy the following requirements: regularity, impulse-free response and rankÊ arbitrary eigenvalues assignment. This parametric characterization conveniently organizes the nonunique gain matrixK to modify the dynamic response of the systems. The result can be used for discrete-time descriptor systems, in which a zero-value eigenvalue may well be a desired closed-loop eigenvalue. One illustrative example is included.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 453-464 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract An efficient bi-state stochastic gradient is proposed for spontaneous constrained time delay estimation. The quantized stochastic gradient is an approximation of the polarity of the instantaneous delay estimation error. It is adjusted in such a way that it has a much higher probability to move in the correct direction at each iteration so as to enable a speed-up in the delay estimate to converge to global minimum in steady state. The performance of the delay estimator is evaluated statistically and an analytical solution for its convergence behavior is established. It is demonstrated that the proposed algorithm has at least a two-fold improvement in convergence speed when compared with the conventional approach, and this is verified by extensive simulation results.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 503-531 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this work, we extend the coding theory approach to error control in redundant residue number systems (RRNS). The concept of erasure correction capability in RRNS is introduced. We derive the relationship between the minimum distance and the error detection and error/erasure correction capability. New computationally efficient algorithms are derived for simultaneously correcting single errors and multiple erasures and detecting multiple errors. These algorithms reduce the computational complexity of the previously known algorithms by at least an order of magnitude. Another attractive feature of the algorithms is that all the arithmetic operations are modulo operations. Consequently, the need to process large valued integers is avoided.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 579-587 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper presents a general expression relating the complex-normalized scattering matrix of ann-port network to that of its augmentedn-port network normalizing to then 1 −Ω resistances, where the Darlington equivalent network may be either reciprocal or nonreciprocal.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 211-221 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Recent research has shown that multilayer feedforward networks with sigmoidal activation functions are universal approximators, and that this holds for more general activations as well. The mathematical underpinning for these results has been various: Kolmogorov's resolution of Hilbert's thirteenth problem; the Stone-Weierstrass theorem; approximation of Fourier and Radon integral representations; and convergence of probability measures. This paper • Rigorously establishes the robustness of feedforward network realizations. • Uses a theorem of Wiener and ideas of translation invariant subspaces to provide conditions for universal approximations toL 1 andL 2 functions by networks, for quite general activation functions. The second result extends and simplifies some of the recent results of Stinchcombe and White, at least for the special cases ofL 1 andL 2 functions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 489-492 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this short note, we establish a simple, yet precise, necessary and sufficient condition for the “right coprime factorization” of a nonlinear feedback control system. As a consequence, we also obtain similar conditions for the “stable right coprime factorizations ” of the nonlinear feedback control system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 557-566 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The pseudorandom sequence of arrays (PRSA) and a method to generate it was reported earlier by the authors. This paper presents another method to generate a PRSA. The mathematical recursion describing the PRSA and some of its properties are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 37-49 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper proposes an effective method to improve the digital redesign method via the block-pulse function approach. The coefficients of the block-pulse function expansion are exactly evaluated such that the desired digitally redesigned feedback gain and forward gain will be obtained. A numerical example is given to demonstrate the effectiveness of the proposed method.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 51-60 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we apply the technique of interval analysis to get bounds on the initial value response of a linearized single machine infinite bus problem when a parameter is varied. It is generally believed that responses for parameter variations in an interval should lie within the responses for the extremums of the parameter variations. This is not generally true and our example demonstrates this. The interval-analysis technique permits getting the overall bound on the response. Further experimentation also revealed that the method has some limitations particularly involving lightly damped long-term dynamics. The technique is useful in finding the robustness of a particular design such as the power system stabilizer for parameter variations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 105-117 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The high-order Yule-Walker (HOYW) method of sinusoidal frequency estimation based on a singular value decomposition (SVD) is known to have excellent statistical performance. Here, we show that the SVD-based step of the HOYW method can be replaced by a computationally more convenient QR decomposition (QRD)-based step, without affecting the asymptotic properties of the frequency estimates.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 85-103 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract For the given observations set of the ARMA (autoregressive moving average) process, the likelihood function depends, not only on model parameters, but on the starting values of the input and output. Therefore, it is called theconditional likelihood function. Theunconditional likelihood function can be obtained in two ways. The first is to set the starting values to zero, as is often done, and the second is to set them to the properly estimated values. The difference between these two types of likelihood functions is significant when the given data sequence is short, and any of the zeros of the moving average part is close to the boundary of the unit circle. In this paper the direct method of starting value estimation and its application to two off-line ARMA estimation algorithms, the maximum likelihood (ML) algorithm and the iterative inverse filtering (ITIF) algorithm, is proposed. Experimental results prove both increased efficiency and stability of these algorithms. The importance of setting the starting values properly is also significant when the recursive algorithm, with previously estimated parameters, has to be restarted. The advantage of the proposed reinitialization method is shown on the recursive lattice algorithm working in the block mode.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 151-151 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 133-149 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we consider nonlinear, infinite networks of purely resistive type where the voltage across a branch of the network is proportional to a fixed power of the current flowing in the branch. It is known that the study of currents in such networks amounts to studying the space of the functions on a network which have finite Dirichlet sums of orderp. Such a study was carried out in [7], [9], and [11]–[14] under the assumption that every node is connected to only finitely many different nodes of the network. In this paper we drop this assumption and work with general countable networks. We prove that most results of the locally finite case, and especially the classification theory, hold true in a more general context. Moreover, we give necessary and sufficient conditions for a network to have only constant Dirichlet finitep-harmonic functions. The relationship with discrete Markov processes is also pointed out.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 155-175 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract One of the major drawbacks of the backpropagation algorithm is its slow rate of convergence. Researchers have tried several different approaches to speed up the convergence of backpropagation learning. In this paper, we present those rapid learning methods as three categories, and implement the representative methods of each category: (1) for the numerical method based approach, the Aitken's Δ2 process, (2) for the heuristics based approach, the dynamic adaptation of learning rate, and (3) for the learning strategy based approach, the selective presentation of learning samples. Based on these implementations, the performance is evaluated with experiments and the merits and demerits are briefly discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 177-210 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The area of artificial neural networks has recently seen an explosion of theoretical and practical results. In this paper, we present an artificial neural network that is algebraically distinct from the classical artificial neural networks, and several applications which are different from the typical ones. In fact, this new class of networks, calledmorphology neural networks, is a special case of a general theory of artificial neural nets, which includes the classical neural nets. The main difference between a classical neural net and a morphology neural net lies in the way each node algebraically combines the numerical information. Each node in a classical neural net combines information by multiplying output values and corresponding weights and summing, while in a morphology neural net, the combining operation consists of adding values and corresponding weights, and taking the maximum value. We lay a theoretical foundation for morphology neural nets, describe their roots, and give several applications in image processing. In addition, theoretical results on the convergence issues for two networks are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 309-329 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract Higher order moment computations are generally necessary wherever the recognition task exceeds the confines of linearity. This paper provides an overview of recent progress on a specific neural network design, which explicitly uses higher order moment information. Attention is focused on the training algorithms used in the design and on network performance in prototype applications.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 375-390 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In the present paper we study the problem of the existence and uniqueness of solutions of implicit systems considered on a finite interval of time. We consider two kinds of existence problems: input-acceptance and input-acceptance when the boundary conditions of a corresponding trajectory are set to zero, and two kinds of uniqueness problems: output uniqueness and output uniqueness when the boundary conditions of the corresponding trajectory are unknown. Geometric conditions for all of these notions are given, and the duality of these notions is studied.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 3-35 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we study the performance of direction-finding systems which attempt to estimate unknown array parameters (such as sensor gains and phases) in addition to the estimation of the directions of arrival (DOA), as a way of performing array self-calibration. We develop compact closed form expressions for the Cramér-Rao bound associated with the joint estimation of DOAs, gains, phases, and the signal covariance matrix. By evaluating the Cramér-Rao bound for selected cases we gain some insight into the performance of direction-finding systems in the presence of gain and phase uncertainties.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 61-83 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract We consider input-output systems (not necessarily of feedback type) on the time domain [0, ∞) which are governed by nonlinear vector integral or differential equations that relate the input and the output. Assuming that these equations depend on a parameterA, describing perturbations, which is allowed to vary in a vicinity of a nominal valueA 0 in a linear space, we study how strongly the output is affected by changes of (a)A 0 when the input is fixed (insensitivity), and (b) the input whenA is fixed withA A 0 being not too large (robust stability). The results are based on the theory of input-output systems over abstract extended spaces given in Parts I and II of [3]. We discuss nominal systems described by nonlinear Volterra and differential equations, and consider two types of possible perturbations. We also prove a simple result on systems governed by singular differential equations whose perturbations can change the order of the system.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 119-131 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A new family of RC-active biquadratic building blocks are proposed in this communication. These biquads are especially designed for MOSFET-C applications, since they achieve a complete MOS nonlinearity cancellation. The proposed circuits can realize all the generic transfer functions such as lowpass, highpass, bandpass, band-rejection, and allpass. They also enjoy low passband sensitivities with respect to passive elements. The gain-bandwidth product-sensitivity is investigated too. An example of a high Q-bandpass filter is given with its Monte-Carlo simulation to verify its sensitivity performance.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 247-261 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A neural network for the traffic control problem applied to reverse baseline networks has been proposed in this paper. This problem has been first represented by an energy function. A neural network is applied for maximizing the energy of the function under the constraints of the reverse baseline network. The number of iteration steps in our neural network is limited by a performed upper bound O(n), wheren is the size of ann ×n network. The throughputs of our neural network have been shown by the empirical results to be better than the conventional algorithm (modified Bipartite Matching Algorithm) when the packet densities rise higher than 50%.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 331-374 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract There are currently several types of constructive, (or growth), algorithms available for training a feed-forward neural network. This paper describes and explains the main ones, using a fundamental approach to the multi-layer perceptron problem-solving mechanisms. The claimed convergence properties of the algorithms are verified using just two mapping theorems, which consequently enables all the algorithms to be unified under a basic mechanism. The algorithms are compared and contrasted and the deficiencies of some highlighted. The fundamental reasons for the actual success of these algorithms are extracted, and used to suggest where they might most fruitfully be applied. A suspicion that they are not a panacea for all current neural network difficulties, and that one must somewhere along the line pay for the learning efficiency they promise, is developed into an argument that their generalization abilities will lie on average below that of back-propagation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 223-246 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A forward-backward training algorithm for parallel, self-organizing hierarchical neural networks (PSHNNs) is described. Using linear algebra, it is shown that the forward-backward training of ann-stage PSHNN until convergence is equivalent to the pseudo-inverse solution for a single, total network designed in the least-squares sense with the total input vector consisting of the actual input vector and its additional nonlinear transformations. These results are also valid when a single long input vector is partitioned into smaller length vectors. A number of advantages achieved are: small modules for easy and fast learning, parallel implementation of small modules during testing, faster convergence rate, better numerical error-reduction, and suitability for learning input nonlinear transformations by other neural networks. The backpropagation (BP) algorithm is proposed for learning input nonlinearitics. Better performance in terms of deeper minimum of the error function and faster convergence rate is achieved when a single BP network is replaced by a PSHNN of equal complexity in which each stage is a BP network of smaller complexity than the single BP network.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 279-307 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A fading-memory system is defined as a system whose response map has unique asymptotic properties over some set of inputs. It is shown that any discrete-time fading-memory system can be uniformly approximated arbitrarily closely over a compact set of input sequences by uniformly approximating either its external or internal representation sufficiently closely. In other words, the problem of uniformly approximating a fading-memory system reduces to the problem of uniformly approximating continuous real-valued functions on compact sets. The perceptron is shown to realize a set of continuous real-valued functions that is uniformly dense on compacta in the set of all continuous functions. Using the perceptron to uniformly approximate the external and internal representations of a fading-memory system results, respectively, in simple nonlinear finite-memory and infinite-memory system models.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 431-440 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract A new statistical test for selecting the order of a nonstationary AR modelyk is presented based on the predictive least-squares principle. This test is of the same order as the accumulated cost function Γ n =∑ k=1 n (∈ k * −∈ k )2;i.e., ∈* wherey k * is the predictive least-square estimate. It is constructed to show how many times the integrated AR processy k is differenced in order to obtain a stationary AR process given that the exact order of the process is unknown.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 465-488 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract New properties useful in connection with 1-D and 2-D lattice realizations are developed. These properties enable one to represent given, complicated 2-D separable-denominator digital filters in terms of simpler, more elemental building blocks which consist of two 1-D lattice realizations having dynamics in different directions and connected in a cascade form. The matrix-relationship between a 2-D discrete Schwarz form and a controller-observer canonical form is also derived. A notable property of the proposed 2-D lattice realization is that the impulse response energy of a 2-D separable-denominator digital filter can be readily obtained from the reflection coefficients and input/output tapped coefficients of the realization.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 533-555 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract This paper investigates the robustness of the saddle-node bifurcation for nonlinear systems under the addition of slow unmodeled dynamics. The robustness is examined in terms of existence and system behavior after bifurcation. Under fairly general conditions, it is shown that if the reduced model of a physical system encounters a saddle-node bifurcation due to a varying parameter, then the original model which includes small unmodeled dynamics will also encounter a saddle-node bifurcation. An error bound is derived between the bifurcation values and the bifurcation points of the reduced model and that of the original model. Furthermore, it is shown that the dynamics after the saddle-node bifurcation of the reduced model and that of the original model are approximately the same. The persistence and non-persistence of saddle-node bifurcations are illustrated by several examples.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 603-612 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract We prove that the current generated by finitely many current sources in an infinite nonlinear resistive network with no shorts at infinity can be approximated in norm by currents in finite open subnetworks.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 441-452 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract For direct form digital filters with integer arithmetic, a characterization of the initial condition vector and state vectorX(ρ), for a fixedρ,ρ 〉 1, is established without the intermediate state vectors. This is used to determine initial conditions for stability and initial conditions for convergence to a limit cycle. Also, several properties of limit cycles are proven.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 495-502 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract We study implementation problems involved with certain adaptive filters requiring high speed matrix-vector multiplies of the formTw, whereT isn×n Toeplitz andw is ann×1 vector. We solve the problem using a novel and simple matrix decomposition of the formT=C+S, whereC is circulant and5 is “factor” circulant.C andS support fast Fourier transform implementations of all basic matrix computations. The decomposition can also be used to implement the productT 1 T 2 with fast Fourier transform algorithms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 567-578 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract The foundations of information theory as a whole, and the rate distortion theory in particular, were ably laid by Shannon in 1948. The rate distortion function R(D) is defined as the effective rate (R) at which the source produces information subject to the constraint that the user can tolerate an average distortion of D. The rate distortion functions for Gaussian Markov Processes were studied by Berger [1] and Bunin [2] for small distortion values. This paper presents the generalization of this study fornth-order Gaussian Markov processes for all distortion levels from 0 toσ 2. The function is first derived, computer simulated, and then calculated for first and second order cases, and the corresponding results are commented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Circuits, systems and signal processing 12 (1993), S. 589-602 
    ISSN: 1531-5878
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology
    Notes: Abstract In this paper we present computationally efficient design techniques for the reduced-order observer problem in generalized state-space systems. The proposed approach utilizes the generalized block Hessenberg form. The problem of reduced-order observer ingeneralized systems is reformulated as a full-order observer problem forstatespace systems. This new approach parametrizes the family of all possible solutions, studies the problem of robustness, and relaxes the condition of observability.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    Mathematics of control, signals, and systems 6 (1993), S. 247-263 
    ISSN: 1435-568X
    Keywords: Robustness ; Time-varying ; Coprime factorizations ; Operator balls ; Linear systems ; Stabilization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics , Technology
    Notes: Abstract We consider robust optimization for time-varying systems in terms of perturbations of fractional representations. Upper and lower bounds are given for the maximal radius of the operator ball around a given plant which can be stabilized by a single compensator. In the time-invariant case, these numbers are equal.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Mathematics of control, signals, and systems 6 (1993), S. 264-288 
    ISSN: 1435-568X
    Keywords: Multidimensional system ; System behavior ; Trajectory ; Exact modeling ; Inverse system ; Gröbner basis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics , Technology
    Notes: Abstract The minimal numberμ(S) of generators of a multidimensional systemS is constructively determined. Such anS is the solution space of a linear system of partial differential or difference equations with constant coefficients. The main theorem generalizes recent results of Heij and Zampieri who calculated the numberμ(S) in the one- (resp. two-) dimensional discrete case. There is also a direct connection with Macaulay's inverse systems in the multidimensional discrete situation, in particular with his principal systems characterized by the relationμ(S)⩽1. It is surprising that, for dimensions greater than one, very many “large” systems are principal in this sense.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Mathematics of control, signals, and systems 6 (1993), S. 322-340 
    ISSN: 1435-568X
    Keywords: Model matching ; Model reference adaptive control ; Nonlinear time-varying controllers ; Causality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics , Technology
    Notes: Abstract In this paper we consider the problem of asymptotic model matching, in which the objective is to force the plant to behave asymptotically like a reference model in response to an exogenous input. Conditions for solvability via a linear time-invariant controller are well known; here we prove that under a closed-loop causality constraint, moving to a nonlinear time-varying controller affords no reduction of these conditions. We explore the ramifications of this result to the (ideal) model reference adaptive control problem, demonstrating that (i) an upper bound on the plant relative degreemust be known, and (ii) the plant zeros in the closed right half-planemust lie in a finite set. We also derive a bound on the achievable asymptotic performance in the event that the solvability conditions fail to hold.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Mathematics of control, signals, and systems 6 (1993), S. 341-362 
    ISSN: 1435-568X
    Keywords: Differential periodic Riccati equation ; Periodic nonnegative definite solutions ; Hamiltonian matrix method ; Special solutions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics , Technology
    Notes: Abstract In this paper we consider the differential periodic Riccati equation. All the periodic nonnegative definite solutions are characterized in the more general case, providing a method for constructing them. The method is obtained from the study of the invariant subspaces of the monodromy matrix of the associated Hamiltonian system, and from the relations between these invariant subspaces and the controllability and unobservability subspaces. Finally, the method is applied to obtain necessary and sufficient conditions for the existence of any periodic nonnegative definite solution and to study the existence and uniqueness of minimal, maximal, stabilizing, and strong solutions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    Mathematics of control, signals, and systems 6 (1993), S. 363-379 
    ISSN: 1435-568X
    Keywords: Nonlinear systems ; Inversion ; Left-inverse system ; Observability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Mathematics , Technology
    Notes: Abstract The left-invertibility and the general construction of reduced inverse systems are studied and described in a unified vector-space approach for both linear and nonlinear systems. The order of reduced inverse systems is calculated by means of intrinsic invariants, which reflect some properties related to observability. The uniqueness of the reduced inverse is described by a factor space.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 789-799 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The optical properties of the interference wedge are analysed for the case of restricted laser beam illumination. By further development of Brossel's method, equations describing this case are derived and used to calculate the reflected and transmitted beam profiles for typical intracavity laser beam diameters (0.2–0.6 mm) for Gaussian and uniform intensity distributions. In particular, the experimentally observed formation of bright fringes outside the beam impact area at resonant wavelengths is explained. some useful dependencies concerning the wedge reflection and transmission for laser applications are obtained and experimentally demonstrated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. v 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 853-858 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We report a simple method to measure relative second-harmonic optical susceptibilities of crystals by use of Rayleigh scattering. We use two crystals with fixed alignments: one is a phase-matched crystal with varying degrees of phase matching, which serves as a reference point of the phase relationship and a source for the second-harmonic beam to be incident on the sample crystal, and the other is a sample crystal for measurement. The second-harmonic signals generated from each of the two crystals are superposed in the sample crystal to give Rayleigh scattering at the second-harmonic frequency, the analysis of which can determine the relative values of the second-harmonic optical susceptibilities of the sample crystals. We have applied this method to obtain d 14 (KDP)≃1.8 d 36 (KDP), d 36 (ADP)≃1.1 d 36 (KDP), d 31 (KTP)≃15 d 36 (KDP), d 32 (KTP)≃13 d 36 (KDP), where d 36 of KDP crystals was taken as a reference.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 859-864 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract An analysis of two-photon interaction was carried out for a two-level system with mixed states parity. Janes-Cummings-type semiclassical equations have been derived for this model and their computer solutions have been analysed; an approximate expression for the ‘Rabi frequency” is given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The influence of interdiffusion on eigenstates in an interdiffusion-induced GaAs/AlxGa1-xAs single-quantum-well structure is analysed numerically by the finite element method. In this approach, the confinement potential profile of the interdiffused quantum well structure is nonlinear and is modelled by an error function and, in particular, the nature of the effective mass of an electron is considered. The results show that the number of eigenstates and energy levels varies with the extent of the interdiffusion. Numerical results for the quasi-bound states in the quantum well structure with an applied electric field are also presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The design, fabrication and characterization of electrooptical modulators and switches based on pseudomorphic InGaAs/GaAs multiple-quantum-well (MQW) structures is presented. The absorption and refractive index changes (Δα, Δn) of In0.2Ga0.8As/GaAs MQW structures due to the quantum-confined Stark effect are examined in detail. The figures of merit Δα/α0 and Δn/α0 give information on the design of modulation and switching devices. Based on these results, we develop two types of efficient and high-speed modulators, vertical and waveguide modulators, and for the first time an InGaAs/GaAs intersectional X-type switch. Recent experimental results for each device are presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Free-space ‘smart-pixel’ optical interconnect architectures promise to relieve the interconnect ‘bottleneck’ in high-speed parallel computers and switching systems. One of the most promising output devices that has been advanced for use in these systems is the asymmetric Fabry-Perot modulator, or AFPM, which offers high on-off contrast, low insertion loss, and low operating voltage swing, among other advantages. In this paper we summarize our work on optimizing the AFPM for high-speed operation, including analysis of the material structure design considerations, fabrication of small (16×20 μm) devices, and high-speed electrical and optical characterization of the finished modulators. We conclude that at relatively high incident optical intensities the modulators' speed appears to be limited by transit effects to about 18 GHz, but that at lower optical intensities their frequency response outstrips that of our 20 GHz measurement apparatus — that is, these AFPMs are still capable of large signal modulation (20 dB contrast, 1.5 dB insertion loss) at low AC voltage swings (±3 V) for operating frequencies up to 20 GHz. We presume that further investigation will prove them to be RC-limited in this low-intensity regime to speeds of about 35 GHz.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. S917 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A new type of multiple quantum well (MQW) reflection modulator, based on the multilayer active antireflection coating (A-ARC) is proposed and compared theoretically with the conventional MQW modulator based on the asymmetric Fabry-Perot etalon (AFP). It is shown that both a large on-off ratio and a low operating voltage can be achieved. It will be demonstrated that the A-ARC device matches the performance of the recently reported asymmetric Fabry-Perot modulator while requiring smaller device thickness. It will also be shown that A-ARC MQW modulators exhibit superior tolerance to the unavoidable thickness variations, thus allowing fabrication of large-area uniform arrays of modulators.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 139-145 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Noise gratings recorded with single-beam exposures in bleached silver halide emulsions are analysed as a function of chemical processing. Two types of bleach baths were used in these experiments (one reversal and the other rehalogenating) and the characteristics of these gratings were determined by measuring the transmittance through the processed hologram as a function of the replay angle. The results obtained show that the study of these noise gratings provides information about the bleaching action during the processing.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 163-170 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A fibre ring resonator with coupling via an asymmetric twin-core single-mode coupler with variable mismatch is analysed. It is found that by varying the mismatch in the coupler the resonance conditions of the ring are also changed. Suitable choices of device parameters allow the resonance to be tuned over a range of wavelenths by altering the coupler mismatch.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We have performed the first experiment on the free-electron laser (CLIO) at the Laboratoire pour l'Utilisation du Rayonnement Électromagnétique (LURE). In a transmission experiment we observed strong power limiting at wavelengths longer than the absorption edge associated with induced free carrier absorption produced by direct interband two-photon transitions in InSb. We have estimated the two-photon absorption (TPA) coefficient (β) of InSb at 8.9 μm to be 2 cm MW-1, by fitting the power-limiting effect with a simple theoretical model. An important feature of this result is that we are utilizing the broad tunability of the FEL to explore the TPA theory to shorter wavelengths than hitherto available with CO2 lasers. The result is in broad agreement with the longer-wavelength measurements of Sheik-Bahae et al.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 177-183 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Silver halide light-developing layers are used as adaptive filters for interferogram processing.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 195-200 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Acoustooptic collinear TE-TM mode conversion was investigated in a two-layer Ti-indiffused and proton-exchanged waveguide structure in LiNbO3. A very narrowband interaction of only 130 kHz (0.31 nm optical bandwidth) was achieved with about 25 mW acoustic power for 96% conversion efficiency. This structure is especially suitable for constructing novel-type acoustooptical gas sensors.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 185-193 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We study for the first time the evolution of the guided field in a 1×7 fibre coupler with a third-order nonlinearity. An analytical solution of the nonlinear coupled-mode equations is presented in terms of the Weierstrass function. In particular, we found that contrary to the equal power distribution in the linear limit, a cross-state appeared if the coupler was initially excited in the central core and a certain input power was chosen. Finally, we analyse the far-field pattern of the coupler output.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 215-218 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 201-206 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We demonstrate the possibility of determining simultaneously the parameters of optical fibres using a stimulated four-wave mixing method without the requirement of considering the particular refractive index profile. The most suitable modal combinations that minimize the error in neglecting the refractive index profile are found and their dependence on the value of the V parameter. Experimental results that verify the accuracy of the proposed method are also given.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 241-253 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A technique based on self-imaging at finite conjugates has been experimentally demonstrated for visualization of laser-induced photorefractive gratings in BSO. A simple model theory has been used to provide the correct rules of geometrical optics of self-imaging. A novel technique has been used for photoinducing the periodic structure. An application has been made to determine the harmonic components of the nonsinusoidal refractive index modulation in the BSO for a grating period of 10 μm and for external DC voltages of 6.0 and 3.0 kV. The technique is directly applicable to the visualization and study of laser-induced gratings (LIG) in thin nonlinear optical media.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 231-239 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Illumination of a photorefractive crystal by light containing two interference patterns (generally running) is considered. As well as linear terms in the response, the nonlinear ones are calculated, corresponding to sum and difference spatial frequencies. Efficient recording of those nonlinear gratings due to temporal phase-matching, i.e. phaselocked detection, is predicted under the application of spatially homogeneous field with DC and/or with sinusoidal time dependence. Thresholds for parametric instabilities of the types of subharmonic generation are calculated for different cases.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 207-213 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The nonlinear coupling characteristics of the nonparallel coupler due to photorefraction is investigated using coupled mode theory with a step-like refractive index profile. The calculated results show no significant degradation of the performance of the device when less than 3×104 W cm-2 optical intensity is coupled into the waveguide. The optically induced drift effects depend on the structural geometry and the initial light intensity. Means of reducing the crosstalk induced by the photorefractive damage are also presented. Numerical results are given to illustrate the nonlinear coupling characteristics of various structures and to establish useful guidelines for the design of nonparallel directional couplers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 219-229 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The low-loss, wide-bandwidth capability of optoelectronic systems makes them attractive for the transmission and processing of microwave signals. This paper considers the technology required for generating, transmitting and detecting microwave modulated optical signals. It also reviews the developing research area of directly optically controlled microwave devices, and describes some typical microwave optoelectronic systems applications.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 255-260 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We propose a tapered electrode structure to make the ratio of the coupling coefficient to the difference of propagation constants between two coupled waveguides in a directional coupler switch a constant throughout it. In this way, the crosstalk caused by the existence of tapered sections is entirely eliminated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 261-269 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A copper HyBrID laser (λ=510.6, 578.2 nm) is reported which produced 121 W at 2.2% efficiency (based on stored energy), with a pulse recurrence frequency of 18 kHz. For an output power of 100 W, the efficiency was 2.6%. A 21% enhancement in output power was achieved by eliminating parasitic stimulated emission due to back-reflection from the silica discharge-tube windows.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 285-290 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 271-273 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Passive pulse stretching in a Q-switched Nd: glass laser using a dye as a two-photon absorber is described. The lengthening of pulses was evaluated by means of computer calculations. Pulses 350-ns long have been observed experimentally.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 291-291 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 275-284 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The method of Gaussian beam ray-equivalent modelling, first proposed by Arnaud, is generalized to the case of general astigmatism. It has been shown that a generally astigmatic Gaussian beam can be properly represented by two complex rays, or equally by four real rays, which are treated by the well-known propagation equation and ray tracing method in geometric optics, and from which the beam parameters are easily obtained. Illustrative numerical examples are given. The equivalence between the complex-ray treatment and the generalized ABCD law is also shown.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 317-349 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Intense picosecond light pulses of a mode-locked Nd: glass laser at λ L =1054 nm (fundamental wavelength) and λ SH =527 nm (second harmonic wavelength) are passed through a sample of D2O under self-focusing conditions. Spectrally structured superbroadened, spatially bell-shaped emission in the forward direction is obtained. Primary generation processes are pump-pulse-degenerate stimulated parametric four-photon interaction (ω1 + ω1 → ω3 + ω4) and stimulated Raman scattering (ω1 → ω R + ωυ), which occur concurrently (ω1=ω L or ω SH angular pump frequency, #x03C9; R first Stokes frequency, #x03C9;υ signal frequency, #x03C9;3 signal frequency, #x03C9;4 idler frequency). The parametric four-photon interaction occurs under collinear non-phase-matched conditions and under longitudinally phase-matched, transversally non-phase-matched (Čerenkov-like) conditions. Subsequent interaction processes are pump-pulse-nondegenerate four-photon interaction of the type ω1 + ω R → ω3′ + ω4′, coherent antiStokes Raman scattering (CARS, ω1 + ω1 − ω4 → ω3), inverse Raman scattering (ω A + ω1 + ωυ), and cascading light up-conversion of the type ω1 + ω (i) − ω R → ω(i+1).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 311-316 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A Raman transition induced by a twin photon beam with quantum correlation, which is generated by nondegenerate parametric down-conversion, is theoretically analysed. The signal intensity of induced Raman scattering for the twin photon beam is twice as large as that for two coherent beams without correlation. Application of the twin photon beam is proposed for optical measurements of ESR spectra, which are useful for investigation of dislocations in semiconductor materials.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 359-367 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The output intensity of an erbium-doped fibre laser was studied. Experiments were performed with three pumping wavelengths: 514.5 nm, 810 nm and 980 nm. The laser output intensity exhibits three different dynamical behaviours: steady-state, sinusoidal variation or self-pulsing. In particular, in a bad (high-loss) cavity configuration, when the pumping ratio is increased above the lasing threshold the output intensity changes continuously from a steady-state to an infinite train of pulses. We also show that, depending on the cavity configuration, the transient oscillations display different forms.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 368-368 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 369-369 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 351-358 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A two-level model of recording and readout of holographic gratings in photorefractive crystals proposed by Rustamov has been developed for the nonstationary case. Based on the joint solution of kinetic equations and Maxwell's equations in the quasistationary approximation, a system of coupled partial differential equations for slowly varying optical wave amplitudes has been obtained. The use of a truncated power series expansion has allowed an expression to be obtained for diffraction efficiency in the nonstationary case. The dynamics of diffraction efficiency development is in satisfactory agreement with the available experimental data.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 369-390 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Several approaches have been developed for modelling the gain and saturation behaviour of semiconductor lasers, and this study includes a historical review of these various approaches. Special attention is given to rate equation models and to the possibility of so-called gain nonlinearities that might affect the CW and modulation performance of semiconductor lasers. Discussions are mainly limited to the GaAs/GaAIAs and InGaAsP/InP systems, for which the gain and gain nonlinearities have been most extensively studied.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. S597 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Capacities for angular and wavelength multiplexed holographic data storage systems are considered. Limitations due to the spatial resolution of the recording and reconstructing fields and to the holographic recording process are derived.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. S569 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We show that materials with the ability to form persistent spectral holes under illumination have frequency as an additional optically parallel accessible degree of freedom that may be incorporated into associative memory. This opens new possibilities for increasing the number of interconnections in optical models of neural networks. In our first example, a 144-element autoassociative memory matrix is constructed on two 12-bit vectors and has two dimensions (x and frequency ω). The probe vector at the memory input carries two erroneous bits (out of 12 bits) and is onedimensional (spatial coordinate x); the memory output-with the error bits correctedis one-dimensional in frequency ω. The second example uses memory input that is twodimensional (image in coordinates x, y); the memory matrix is four-dimensional (x, y ω, t), where t (time coordinate) is given by the temporal delay of photochemically accumulated stimulated photon echo signal; memory output is two-dimensional (ω and t) and corrects two bits out of the 12-bit vector. In the third example, quadratic autoassociative memory is coded in three dimensions (coordinates x, y, ω) and materializes 32×32×32=32768 optical interconnections; the probe vector is given as a 32×32 spatial matrix (coordinates x, y); the output is one-dimensional, consists of 32 bits along the frequency axis, and corrects four erroneous bits.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. S587 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The fundamentals of current optical disk technology were developed in the 1970s, and the optical disk production facilities and business infrastructure were installed in the 1980s. Thus, we are now entering the third decade of the history of optical disk technology. It will be very interesting to see whether we can keep up the same momentum in technological development during the 1990s. In this paper, the state of the art of the current technologies and some of future developments in the 1990s are discussed. A wide range of techniques for increasing the recording density and obtaining higher transfer rates are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. S611 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We consider holographic optical data storage systems implemented with photorefractive media. Our viewpoint emphasizes the close interaction between materials and device issues. First we discuss our current understanding of photorefractive physics as it pertains to the holographic data storage problem. Then we consider architecture issues, including angular, phase-encoded, and wavelength-multiplexing techniques, and several approaches to increasing the signal-to-noise ratio of the recordings. Finally, we discuss materials issues related to crystal growth and how crystal quality impacts the performance of data storage systems. Both bulk and fibre crystal growth techniques are reviewed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 27-35 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Diagrammatic analysis applied to the stationary version of the equations describing electron and photon kinetics in semiconductor injection lasers reveals the existence of a feedback loop in the pattern of mutual relationships between parameters. Associated with this loop is the concept of causal feedback. The analysis affords simple approximate expressions for the photon density versus pumping rate characteristic. A fundamental system-theoretical meaning is found for the laser threshold condition as one for which the transmission function of the feedback loop equals-1.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 1-25 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Picosecond light pulses of a passively mode-locked ruby laser (pulse duration Δt L≈35 ps) are spectrally broadened in optical fibres of core diameters from 4 μm to 600 μm. Combining the effects of self-phase modulation, stimulated Raman scattering, and parametric four-photon interaction in an 8-μm core fibre of 4 m length with the effect of selective spectral attenuation in a ruby rod resulted in rather smooth spectra extending from 685 nm to 830 nm (spectral width ≈2300 cm-1).
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 63-74 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We report on a full-scale numerical simulation of the coherent photon seeding technique applied to colour-centre lasers with counterpropagating beams. The stabilization technique is proved to be simple and efficient independently of the interferometric precision of the coupled cavity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 57-62 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The variational analysis of Ti:LiNbO3 strip waveguides is resolved into two related one-dimension problems, which provides a new iterative approach for the calculation of the mode parameters and the propagation constant. The analytical expressions of the local effective index profiles can be obtained from the variational analysis. The parameters of four trial solutions for the fundamental mode in a diffused-channel waveguide have been determined by using the present method. Comparison with results using the effective method shows that these four approximate expressions are accurate enough. It is also shown that this method converges very quickly and is suitable for both diffused channel waveguides and optical waveguides with rectangular cross-section.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 78-78 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 75-77 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 37-55 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract An exact numerical analysis is given of electron waves in a pair of coupled semiconductor heterojunction electron waveguides modelled by a rectangular potential distribution. The waveguide lengths required for electron current transfer between the guides agree asymptotically with estimates from Yariv's coupled mode theory and are usefully more accurate. Moreover the electron wave coupling due to an ideal launcher can be worked out, leading to estimates of the off/on current ratio η occurring in the waveguides when regarded as an ultrafast switch. For a Poisson probability distribution of the number of electrons N making up a bit-pulse, we have calculated the minimum average N, dependent upon η, which would be required to keep the switching bit-error rate below prescribed limits. Pulse rise times and switching delays are derived from the explicit forms for the longitudinal electron wave group velocity. Combining the bit-error and switching-time calculations leads to estimates of the waveguide current densities which would be required in practice. Some normalized sets of curves relating to our analysis are given and used to predict the performance of particular examples of recently proposed AlGaAs/GaAs heterojunction electron waveguide switch/couplers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 675-693 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The dynamical behaviour of Fabry-Perot type semiconductor lasers is modelled, including the relevant many-body Coulomb effects of the excited carriers. Conditions are given under which a parametrization of the full model is possible, allowing simple analytic relations for local gain, refractive index and linewidth enhancement factor. The parameters of the simplified model are uniquely determined by the microscopic theory and have to be optimized for the respective operating conditions. The theory is evaluated for bulk and quantum-well GaAs active material and a variety of laser structures, including strongly and weakly index-guided structures, as well as purely guided single-and twin-stripe lasers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A new experimental method is proposed for measuring the refractive indices of liquids based on mode line measurements. The experimental setup consists of a dielectric substrate in which a rectangular hollow is formed containing the concerned liquid. This is covered by a trapezium-shaped prism. The liquid, confined between both basin walls and the prism, forms a wavegude. Thus, the refractive index of the liquid can be determined by measuring the propagating modes in the structure. Using this technique, the refractive indices of liquids can be measured to an accuracy of the order of 1×10-4.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 663-674 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We consider optical bistability and multistability based on the theory of bidirectional oscillations induced by four-wave mixing (FWM) in a photorefractive (PR) phaseconjugate ring resonator model. Bistable and multistable effects of the intensity of oscillation have been established numerically using a successive bisection method that can predict repeated roots as well as discontinuities.Oscillation intensities are studied as a function of parameters such as the nonlinear coupling strength (gL), the ratio of pump beam intensities (R) and the product of reflection coefficients of three cavity mirrors (|r|). It is shown that for certain combinations of these parameters and assuming that gL exceeds its threshold value, the oscillation intensity becomes double-valued or multivalued corresponding to the number of oscillating modes in the cavity. The multiplicity of solutions as well as the possible regions of bistable/multistable branches are greatly affected by the sign of gL and also depend on whether R and |r| are greater than or less than unity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We report on the performance at 1.55 μm of a hybrid receiver combining an In0.47Ga0.53As metal-semiconductor-metal photodetector (with buried AllnAs buffer layer) with a GaAs MESFET preamplifier. A bit error rate of 10-9 is measured at 1 Gbps with nonreturn to zero pseudorandom bit sequence (215–1) at a received optical power of −19 dBm. Modification of the preamplifier design and a reduction of bond pad size could improve the sensitivity by ∼6–7 dB.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A narrowband far-infrared laser on intersubband transitions of hot holes was constructed and investigated. Two methods were used: mode selection due to intercavity Fabry-Perot resonator and selection of a narrow spectral lasing region by special multilayer mirror. The emission spectra of the laser were determined. The radiation bandwidth measured was Δν≤0.2 cm-1 as compared with Δν≃15–30 cm-1 for nonselective resonator. Lasing with selective resonator could occur at any two wavelengths in the ranges 80–120 and 150–200 μm. The wavelength was modified by altering electric and magnetic fields. The radiation power was about 10 W and of the same kind as that of a laser without a mode selector. The narrowband laser was used in investigation of CR of electrons in n-InSb.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 751-759 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Transient features of self-terminating copper vapour lasers (CVLs) based on rate equations are analysed with approximate and exact numerical treatments. It is demonstrated from the former analysis that a predictable maximum value of the laser output in a pulsed CVL is at most the order of one hundred times the steady-state value and from the latter analysis that the features of relaxation oscillation of the CVL on the phase-plane are different from those in the usual relaxation oscillation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 733-744 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The operation of gated saturable absorbers is described by the classical space-time-dependent rate equation model considering both ground-state and excited-state absorption and stimulated emission. The effect of different molecular and cavity parameters on the transmitted pulse is shown.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 723-731 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Conjugated polymers with sidegroups such as methyl, trimethylsilyl, p-methoxy phenyl, o-methoxy phenyl, and hexyl groups on a polyphenylacetylene chain are studied in an attempt to understand the contribution of factors such as the backbone, conformation of the chain, sidegroups and polymerization catalyst on the optical nonlinearities. The results of degenerate four-wave mixing experiments at 532 nm with nanosecond pulses indicate that the substitution of an electron-donating group away from the backbone can enhance the third-order susceptibility. Some of the polymers show optical limiting action at this wavelength. The thermal contribution to the measured susceptibility is also determined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract We report the results of a room-temperature CW top surface-emitting laser whose light-emitting window is much smaller than the current injection area. The lowest series resistance of device is 50 Ω. It maintains single transverse mode at high current levels.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 761-770 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Theoretical expressions and convergence conditions are developed here for the output of a feedback holographic associative memory. It is shown that a feedback holographic associative memory becomes a pinhole holographic associative memory under certain conditions, and thus is a generalization of the pinhole holographic associative memory. The crosstalk in the output of a feedback holographic associative memory can also be removed by a threshold device or controlled by the overall optical efficiency of the memory. A simulation is provided to verify the theoretical results shown here. Using the theoretical results and simulation verification, a feedback holographic associative memory can be designed efficiently. In addition, if a threshold device is used, optical elements with high optical efficiency can be used in a feedback holographic associative memory.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 771-787 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The scope of the spectral index method for solving general planar waveguiding problems is analysed by first showing how simple it is to set up a closed-form transcendental equation whose solution is very accurate; the solution is so fast that the method can be used as a subroutine, making it possible to solve many two-dimensional problems fully, even for coupled rib waveguides, without using effective index approximations. The method is then extended to the uniformly buried waveguide of rectangular cross-section, and the corresponding coupler, thereby unifying the effective index, transverse resonance and spectral index methods for the first time, and giving an asymptotic expression for the coupling length without using overlap integrals. Finally, sample numerical results and optical field profiles are given for the rib waveguide and rib waveguide coupler.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 801-814 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract Using numerical and analytical approaches, we have computed the optical elements (focusators) required for focusing laser light into a narrow ring, a wide ring and a set of rings. A numerical comparison of the various computational techniques is reported. Finally the operation of a fabricated rotor axicon to focus light into a ring is reported.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 113-122 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract This paper describes a rate equation model that has been formulated for an SF6 saturable absorber. The model includes three transitions in the ν 3 ladder and one hot band transition along with intramolecular V-V relaxation to the bath states. The coupled differential equations were solved using the Runge-Kutta method. The transmission characteristics have been calculated for several combinations of pulse length, cell length and SF6 pressure. Theoretical values of transmission are compared with the experimental data of Haglund et al., Taylor et al. and Daido et al., and it is found that the model explains the absorption behaviour more closely.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 429-449 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A theoretical and experimental study of light polarization modulation in single-mode anisotropic optical fibres is presented. The problem of increasing polarization modulation efficiency in slightly and strongly anisotropic fibres is considered. The requirements to be met by the optical configuration for efficient polarization modulation with both slightly and strongly anisotropic fibres are discussed. The polarization modulation signal is found to be immune to external effects on the fibre under compensated birefringence. An experimental polarization modulation-based ‘fibredyne’ video transmission data highway is presented.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 483-488 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Electronic Resource
    Electronic Resource
    Springer
    Optical and quantum electronics 25 (1993), S. 451-465 
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The deterioration of gain in electron-beam-pumped semiconductor lasers with increase in the diameter of the pumped region has been attributed to a reduction in the degree of inversion caused by amplified spontaneous emission. Theories of amplified spontaneous emission in such surface-emitting lasers are advanced in which spatial and spectral inhomogeneities of gain are taken into account. Experiments to determine the dependence of laser threshold and differential efficiency on the diameter of an excited circular region demonstrate good agreement with the threshold predictions of the linear theory; however, the lack of agreement in differential efficiency suggest that a nonlinear phenomenological theory be considered. Data for such calculations are provided from experiments on saturation of spontaneous emission. The resultant nonlinear theory is shown to account well for the observed dependence of differential efficiency on the diameter of the excited region.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...