ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 2651-2658 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We relate the linear electro-optic coefficients to the quadratic polarization-optic and the elasto-optic tensors by analyzing the dielectric phenomena driven by the spontaneous and induced polarization as well as the mechanical effects given by the deformation of the crystals. We determine the temperature dependence and the wavelength dispersion of the electro-optic tensor in all the ferroelectric phases from a smaller set of data: the quadratic polarization-optic tensor of the cubic phase, the dielectric permittivity, and the spontaneous polarization. Under the assumption that the elasto-optic tensor at constant polarization is constant, the elasto-optic coefficients at constant electric field in the ferroelectric phases are derived. Numerical evaluations of these coefficients for two perovskite crystals KNbO3 and BaTiO3 are presented. Modifications of the electro-optic properties in doped crystals, mainly due to a change of the dielectric permittivity, are discussed as well. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 6114-6120 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Results on annealing experiments of He+ ion-implanted KNbO3 planar and channel waveguides are reported. Annealing at 150 °C for several hours leads to a reduction of the waveguide attenuation constant by more than 5 dB cm−1 at a wavelength of 457 nm without significant change of the profile of the mode confining barrier. A minimum waveguide attenuation constant of 1.3 dB cm−1 in planar and 2.2 dB cm−1 in channel waveguides at 515 nm was achieved. Second-harmonic generation measurements in the waveguides showed that the conversion efficiency can be improved by more than a factor of 2 by the annealing process. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 3665-3668 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Efficient optical pumping of impurity levels in BaTiO3 is achieved using low intensity ultraviolet (UV) exposure. The resulting large photoinduced absorption in the visible is assessed in the context of interband charge transfer. An induced absorption of up to 12 cm−1 is observed at 633 nm. The effect, which takes place close to the UV-exposed crystal surface, occurs on a millisecond time scale. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 1099-1102 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The refractive index profile of na of ion-implanted potassium niobate (KNbO3) planar waveguides is evaluated for waveguides fabricated with ion energies between 2.0 and 3.5 MeV and doses between 7.5×1014 cm−2 and 3.0×1015 cm−2. The measured mode index values are fitted to a quantitative model that correlates the index profile with the irradiation parameters. The reconstructed profile of na is compared to the profiles of nb and nc which have been determined previously. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 2064-2066 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present a novel organic crystal, 5-(methylthio)-thiophenecarboxaldehyde-4-nitrophenylhydrazone, with a large effective phase-matchable nonlinear optical coefficient, deff=29±3 pm/V at λ=1318 nm. Single crystals of dimensions up to 25×5×5 mm3 were grown. The large off-diagonal nonlinear optical coefficients can be explained with the two-dimensional geometry of the chromophores in the crystal lattice. Our crystal is ideally suited for optic parametric oscillation in the wavelength range from 1000 to 2500 nm. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 1186-1195 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ridged channel waveguides in KNbO3 were produced using He+ ion implantation, photolithographic masking, and subsequent Ar+ ion sputtering. We investigated the linear and nonlinear optical characteristics of the waveguides. The effective mode indices are derived from the refractive index profiles using the effective index method. The losses are investigated as a function of wavelength and of the geometrical parameters channel width and ridge height. A minimum loss of 2 dB cm−1 is measured at a wavelength of 0.633 μm. We investigated the power handling capabilities at visible and near-infrared wavelengths. Second-harmonic generation in these waveguides is studied both theoretically and experimentally with regard to its dependence on the guide fabrication parameters. Phase-matching configurations for blue light second-harmonic generation are evaluated on the basis of the dispersion of the effective mode indices. Overlap integrals are calculated on the basis of the field distributions derived from the refractive index profiles. The minimum effective guide cross section is 25 μm2. A continuous-wave second-harmonic output power of 14 mW at 438 nm was obtained with an in-coupled fundamental power of 340 mW in a 0.73 cm long waveguide, yielding a normalized internal conversion efficiency of 25% W−1 cm−2 (13% W−1). This corresponds to an improvement by a factor of 3 compared to the best results reported for KNbO3 waveguides up to now. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 1709-1717 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Light-induced space-charge fields and the related orientational photorefractive effects in nematic liquid crystal cells are studied both theoretically and experimentally. Analytical solutions for the refractive index change distribution are obtained under the single-elastic-constant approximation with various configurations of externally applied electric and magnetic fields and of the nematic liquid crystal director. The effects of the rigid boundary condition are investigated in detail. The grating spacing for which the refractive index change is maximized depends on the strength of external electric and magnetic fields. The responses of parallel cells differ from those of homeotropic cells, both upon the dependencies on the grating spacing and on the external fields. Under the same conditions, the orientational photorefractive effects are stronger in parallel cells than in homeotropic ones. It is also shown that the investigated effects will be greatly enhanced near the Freédericksz transition. Experimental verifications of the photorefractive response in parallel aligned cells confirm the necessity to consider the boundary conditions explicitly. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 67 (1995), S. 748-750 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on the depth profile of the nonlinear optical susceptibility in ion-implanted potassium niobate (KNbO3) waveguides using reflected second harmonic generation from wedged samples. After irradiation the waveguide layer exhibits partial loss of its optical nonlinearity that can be recovered to better than 90% of its value of the virgin crystal by subsequent annealing and repoling. We propose microscopic depolarization due to ion implantation to be responsible for the observed decrease of the nonlinear optical susceptibility. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 2364-2366 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ridged channel waveguides in KNbO3 were fabricated by a technique using He+ ion implantation, photolithographic masking, and subsequent Ar+ ion sputtering. A continuous-wave second-harmonic output power of 14 mW at 438 nm was obtained with an in-coupled fundamental power of 340 mW in a 0.73 cm long waveguide. Phase matching was provided by material birefringence without need of periodic poling. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 98 (1994), S. 6399-6407 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    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...