A. Al-Muhanna
University of Wisconsin-Madison
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Publication
Featured researches published by A. Al-Muhanna.
Applied Physics Letters | 1998
A. Al-Muhanna; Luke J. Mawst; D. Botez; D. Garbuzov; Ramon U. Martinelli; John C. Connolly
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) PCOMD 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 effic...
Applied Physics Letters | 1997
A. Al-Muhanna; Luke J. Mawst; D. Botez; D. Garbuzov; Ramon U. Martinelli; John C. Connolly
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.
Applied Physics Letters | 1998
A. Al-Muhanna; J.K. Wade; Thomas Earles; J. Lopez; Luke J. Mawst
Compressively-strained InGaAsP QW active (/spl lambda/=732 nm) diode lasers achieve 2.4 W CW front-facet power from 100 /spl mu/m-wide apertures, with reliable operation at 0.5 W CW. Record-high characteristic temperatures for the threshold current and the differential quantum efficiency, T/sub 0/=115 K and T/sub 1/=285 K are obtained by growing on misoriented substrates.
Applied Physics Letters | 1998
A. Al-Muhanna; J.K. Wade; Luke J. Mawst; R. J. Fu
0.73-μm-emitting, Al-free active-region, strained (Δa/a≈1.4%) InGaAsP single-quantum-well diode lasers have been grown by low-pressure metal–organic chemical-vapor deposition. A broad waveguide laser design with In0.5(Ga0.5Al0.5)0.5P cladding layers is utilized to achieve a large effective transverse spot size (d/Γ=0.433 μm) and to minimize carrier leakage from the active region. Threshold current densities of 514 A/cm2 (100-μm-wide stripe, L=1 mm), external differential quantum efficiencies of 60%, and characteristic temperature coefficients for the threshold current, T0, and external differential quantum efficiency characteristic temperature, T1, have values of 72 and 153 K, respectively. Continuous wave output powers of 1.4 W are obtained from facet-coated (90%/10%) devices operating at 735 nm.
Applied Physics Letters | 2002
J. C. Chang; Jaeseong Lee; A. Al-Muhanna; Luke J. Mawst; D. Botez
An above-threshold analysis of 8–10-μm-core antiresonant reflecting optical waveguide (ARROW) lasers is performed, including the carrier-induced index depression, carrier diffusion, and gain spatial hole burning (GSHB). The study is done as a function of the (transverse) optical-mode confinement factor Γ and the core width. Just as for index-guided devices, it is found that ARROW devices (i.e., index-antiguided devices) are much less immune to multimoding via GSHB the smaller the value of Γ. For the case Γ=3%, the high-order mode of most concern reaches the threshold much earlier than for the case Γ=1%, due both to gain-profile distortion as well as to distortion of the effective-index profile (in the device core) with increasing drive level. Devices of 8.5-μm-wide cores and Γ=1%, are found to stay single-mode to at least 40× threshold, which in turn allows the projection of stable, single-mode operation to 1.2 W output power. In contrast, 10-μm-core devices become multimode at around 10× threshold. Preli...
lasers and electro-optics society meeting | 1997
A. Al-Muhanna; J.K. Wade; Luke J. Mawst; R.J. Fu
Summary form only given. 0.78 /spl mu/m, Al-free active-region, compressively-strained (/spl Delta/a/a=0.85%) InGaAsP quantum well diode lasers have been grown by MOCVD. Broad-stripe (100 /spl mu/m-wide) devices exhibit low threshold current densities, 290 A/cm/sup 2/ (L=1 mm), and cw front-facet output powers of 2.2 W.
lasers and electro optics society meeting | 1998
A. Al-Muhanna; J.K. Wade; T. Earles; Luke J. Mawst
Compressively-strained InGaAsP QW active (/spl lambda/=732 nm) diode lasers achieve 2.9 W CW front-facet power from 100 /spl mu/m-wide apertures, with reliable operation demonstrated at 0.5 W CW. Record-high characteristic temperature coefficients; T/sub 0/=115 K and T/sub 1/=285 K, are obtained by growing on misoriented substrates.
international semiconductor laser conference | 1998
A. Al-Muhanna; J.K. Wade; T. Earles; Luke J. Mawst; R.J. Fu
Compressively-strained InGaAsP QW active (/spl lambda/=732 nm) diode lasers achieve 2.4 W CW front-facet power from 100 /spl mu/m-wide apertures, with reliable operation at 0.5 W CW. Record-high characteristic temperatures for the threshold current and the differential quantum efficiency, T/sub 0/=115 K and T/sub 1/=285 K are obtained by growing on misoriented substrates.
conference on lasers and electro optics | 1998
A. Al-Muhanna; L.I. Mawst; D. Botez; D. Garbuzov; Ramon U. Martinelli; J. Connolly
Here we present a 1.3-/spl mu/m waveguide laser structure, designed to suppress second-order-mode oscillation, that operates to record-high cw power for any type of InGaAs active diode lasers. It also emits in a pure fundamental transverse mode to at least 20 W peak pulsed power.
lasers and electro-optics society meeting | 1997
A. Al-Muhanna; Luke J. Mawst; D. Botez; Dmitri Z. Garbuzov; Ramon U. Martinelli; John C. Connolly
100 /spl mu/m-wide stripe, 0.97 /spl mu/m-emitting Al-free InGaAsP-InGaP-GaAs QW lasers, demonstrate a record value for quasi-CW output power, 14.3 W, low internal losses (/spl alpha/=1 cm/sup -1/), and high differential quantum efficiency (86% for 2 mm-long lasers). Long cavity, large-stripe devices exhibit relatively small spectral broadening with increased output power.
