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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 7220-7223 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Single-frequency, in-phase mode operation has been obtained from a ten-element antiguided phase-locked array with Talbot-type filters by incorporating a buried distributed feedback grating using a three-step metalorganic chemical vapor deposition process. Stabilized frequency with 25 dB side-mode suppression ratio is achieved to 50 mW pulsed output power. In-phase or a mixture of in-phase and out-of-phase modes are observed in nonresonant (nonoptimized) devices. Means of improving device performance (e.g., use of resonant longitudinally uniform arrays or nearly resonant Talbot-filter arrays without gratings in the filter) are discussed.
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  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 16-18 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: For the first time, high performance GaAs/GaAlAs surface-emitting lasers with internal 45° micromirrors, which totally reflect and emit the beam from the substrate in junction-down configuration, have been demonstrated. The 45° and 90° mirrors of the device were fabricated by using ion milling and reactive ion etching techniques, respectively. Typical threshold current density of 440 A/cm2, external differential efficiencies of 52%, and output power in excess of 1 W under quasi-cw operation have been achieved.
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 2070-2072 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Twenty-element near-resonant AlGaAs/GaAs arrays of antiguides have been optimized for maximum intermodal discrimination and large Strehl ratio. It is found that 1000-μm-long devices with two intracavity Talbot-type spatial filters, and a 3 to 1 ratio between element core and interelement spacing provide the best results. The intermodal discrimination is discussed for both Talbot and uniform devices. For devices with two Talbot-type spatial filters, diffraction-limited-beam operation is obtained to 1 W pulsed power, and operation in a beam with lobewidth 1.5× diffraction limit is obtained to 2 W and 19× threshold. cw diffraction-limited-beam operation is obtained to 0.5 W, limited by thermal considerations. Uniform devices operate in beams with lobewidth ≈3× diffraction limit to 5 W and 45× threshold. At 5 W total output the coherent uniphase power is 1.6 W, and the coherent power in the main lobe is 0.94 W.
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  • 4
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 58 (1991), S. 22-24 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Monolithic phase-locked resonant arrays of antiguides, resonant optical-waveguide (ROW) arrays, have been optimized for efficient in-phase-mode operation. Diffraction-limited, in-phase-mode continuous-wave (cw) operation is obtained from 20-element uniform arrays to 250 mW output power, with (front facet) external differential quantum efficiencies of 41%. Single longitudinal mode operation is observed below 100 mW cw. In-phase-operating devices with and without Talbot-type spatial filters are compared, and it is found that for ROW arrays Talbot-type spatial filters are not required.
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  • 5
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 1182-1184 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: By incorporating a broad transverse waveguide (1.3 μm) in 0.97-μm-emitting InGaAs(P)/InGaP/GaAs separate-confinement-heterostructure quantum-well diode-laser structures we obtain record-high continuous-wave (cw) output powers for any type of InGaAs-active diode lasers: 10.6–11.0 W from 100-μm-wide-aperture devices at 10 °C heatsink temperature, mounted on either diamond or Cu heatsinks. Built-in discrimination against the second-order transverse mode allows pure fundamental-transverse-mode operation (θ⊥=36°) to at least 20-W-peak pulsed power, at 68×threshold. The internal optical power density at catastrophic optical mirror damage (COMD) P¯COMD is found to be 18–18.5 MW/cm2 for these conventionally facet-passivated diodes. The lasers are 2-mm-long with 5%/95% reflectivity for front/back facet coating. A low internal loss coefficient (αi=1 cm−1) allows for high external differential quantum efficiency ηd (85%). The characteristic temperatures for the threshold current T0 and the differential quantum efficiency T1 are 210 and 1800 K, respectively. Low differential series resistance Rs: 26 mΩ; leads to electrical-to-optical power conversion efficiency values in excess of 40% from 1 W up to 10.6 W cw output power, and as much as 50% higher than those of 0.97-μm-emitting Al-containing devices. © 1998 American Institute of Physics.
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  • 6
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 587-589 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A second-order diffraction grating placed below the active region of a phase-locked resonant antiguided array selects the in-phase array mode in addition to its role as a single-longitudinal-mode selector. This type of array-mode discrimination relies on the fact that the resonant in-phase array mode has significantly better field overlap with the grating region than nonresonant array modes. Furthermore, it eliminates the need for a conventional array-mode discriminator: interelement loss; which can cause self-pulsations. Diffraction-limited beam and single-frequency operation is obtained to at least 0.45 W peak pulsed power from 20 element, InGaAs/InGaP/GaAs structures (λ=0.97 μm) of 120-μm-wide aperture. Distributed-feedback operation is confirmed over the 20–40 °C temperature range. The results are in good agreement with theory. © 1998 American Institute of Physics.
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  • 7
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 2869-2871 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Compressively strained InGaAsP quantum well (QW) active (λ=732 nm) diode lasers achieve 2.9 W continuous wave (cw) power from facet-coated (4%/95%) 100-μm-wide apertures, with reliable operation demonstrated at 0.5 W cw power. A broad waveguide structure is used to obtain a large transverse spot size (d/Γ=0.433 μm), resulting in a low internal loss (αi∼2 cm−1) and narrow transverse far-field beam width (θ1/2=38°). Record-high characteristic temperatures for the threshold current and the differential quantum efficiency (T0=115 K and T1=285 K) are obtained by growing on misoriented substrates. © 1998 American Institute of Physics.
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  • 8
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 1142-1144 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Wide-stripe, 0.97 μm emitting Al-free InGaAs(P)/InGaP/GaAs broad-waveguide separate confinement heterostructure quantum-well lasers demonstrate a record value for quasicontinuous wave (QCW) output power: 14.3 W (100-μm-wide stripe, 100 μs-wide pulses); and reach catastrophic optical mirror damage (COMD) in QCW operation at an optical power density of 22.5 MW/cm2; that is, 40% higher than COMD levels in cw operation. The devices have low internal losses (αi=1 cm−1) and high external differential quantum efficiency (86% for 2-mm-long lasers), and exhibit only 10–20 °C temperature rises in the active region at 10 W QCW power. We also show that long-cavity, large-contact-area devices exhibit relatively little spectral broadening with increased output power. © 1997 American Institute of Physics.
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  • 9
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 71 (1997), S. 172-174 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: High power, 0.81-μm-emitting, semiconductor diode lasers are used as pump sources for Nd:YAG solid-state lasers. Devices (1-mm-long) consisting of a InGaAsP/In0.5(Ga0.9Al0.1)0.5P/In0.5(Ga0.5Al0.5)0.5P laser structure provide a threshold-current density, Jth, of 290 A/cm2 and a relatively high threshold-current characteristic temperature, T0 (140 K). Uncoated diode lasers (1.2-mm-long) have a maximum continuous wave output power of 5 W (both facets) at 20 °C. The internal power density at catastrophic optical mirror damage (COMD), P¯COMD, is determined to be 9.1 MW/cm2; that is, 1.8 times that for GaAs-active layer, Al-free, uncoated devices. Coated, InGaAsP-active devices are expected to have P¯COMD=18 MW/cm2, more than twice the P¯COMD of AlGaAs-active, 0.81-μm-emitting devices with the same emitting aperture. Therefore, 0.81-μm-emitting, InGaAsP-active diode lasers should operate reliably at powers at least twice those of AlGaAs-based devices with the same contact-stripe geometry. © 1997 American Institute of Physics.
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  • 10
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Type of Medium: Electronic Resource
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