LOW THRESHOLD CURRENT, HIGH QUANTUM EFFICIENCY 1.5-MU-M GAINAS-GAINAASP GRIN-SCH SINGLE QUANTUM-WELL LASER-DIODES

We have fabricated 1.5-mu-m GaInAs-GaInAsP graded index separate confinement heterostructure (GRIN-SCH) single quantum well buried heterostructure laser diodes (LD's) by metalorganic chemical vapor deposition. They exhibit a low internal loss of 4.3 cm-1, a high quantum efficiency of 37-40%/facet, and a high light output power of 109 mW. A very low threshold current of 6.2 mA and a high characteristic temperature of 94 K were obtained by facet coating. The perpendicular far-field angle is 26-32-degrees, which is smaller than that of GRIN-SCH multiple quantum well LD's. These LD's oscillated at the n = 1 quantized level, not at the n = 2 quantized level.