MONOLITHIC 2-DIMENSIONAL SURFACE-EMITTING STRAINED-LAYER INGAAS/ALGAAS AND ALINGAAS/ALGAAS DIODE-LASER ARRAYS WITH OVER 50-PERCENT DIFFERENTIAL QUANTUM EFFICIENCIES

Monolithic two-dimensional surface-emitting arrays of strained-layer InGaAs/AlGaAs and AlInGaAs/AlGaAs diode lasers have been fabricated and operated pulsed with low-threshold current densities and differential quantum efficiencies greater than 50%. The InGaAs/AlGaAs arrays emit at 1.03-mu-m, while the AlInGaAs/AlGaAs arrays emit at 0.815-mu-m. Thus, it should be possible to fabricate monolithic arrays with comparable performance over a wide wavelength range. The individual lasers of the arrays are horizontal folded-cavity devices with two 45-degrees internal reflectors and two top-surface facets. The design is simple to implement using optical pattern-generator masks, optical projection printing, and chlorine ion-beam-assisted etching in key fabrication steps.