730-NM-EMITTING AL-FREE ACTIVE-REGION DIODE-LASERS WITH COMPRESSIVELYSTRAINED INGAASP QUANTUM-WELLS

0.73-mu m-emitting, Al-free active-region, strained (Delta a/a approxi mate to 1.4%) InGaAsP single-quantum-well diode lasers have been grown by low-pressure metal-organic chemical-vapor deposition. A broad wave guide laser design with In-0.5(Ga0.5Al0.5)(0.5)P :cladding layers is u tilized to achieve a large effective transverse spot size (d/Gamma = 0 .433 mu m) and to minimize carrier leakage from the active region. Thr eshold current densities of 514 A/cm(2) (100-mu m-wide stripe, L=1mm), external differential quantum efficiencies of 60%, and characteristic temperature coefficients for the threshold current, Tg, and external differential quantum efficiency characteristic temperature, T-1, 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 7 35 nm. (C) 1998 American Institute of Physics.