HIGH CONTINUOUS-WAVE OUTPUT POWER INGAAS/INGAASP/INGAP DIODE-LASERS - EFFECT OF SUBSTRATE MISORIENTATION

3 W cw output power has been obtained from aluminum-free, strained-layer double-quantum well (DQW) InGaAs/InGaAsP/InGaP uncoated, 100-mu m-wide stripe diode lasers;(lambda=0.945 mu m) grown by low-pressure MOCVD on exact (100) GaAs substrates. The combination of high-band-gap (1.62 eV) InGaAsP confinement layers and the DQW structure provides relatively weak temperature dependence for both the threshold current I-th as well as the external differential quantum efficiency eta(d). Furthermore, the series electrical resistance for 100 mu mX600 mu m stripe-contact devices is as low as 0.12 Omega. As a result, the power conversion efficiency reaches a maximum of 40% at 8 Xl(th), and decreases to only 33% at the maximum power (i.e., 3 W) at 28XI(th). Low-temperature (12 K) photoluminescence measurements of InGaAs/InGaAsP quantum-well structures exhibit narrow linewidths (<10 meV) for material grown on exact (100) GaAs substrates, while growths on misoriented substrates exhibit linewidth broadening, as a result of ''step bunching.'' Laser structures grown on misoriented substrates exhibit increased temperature sensitivity of both I-th and eta(d), compared with structures grown on exact (100) substrates. (C) 1995 American Institute of Physics.