OPERATION CHARACTERISTICS OF BURIED-STRIPE GAINASP-INP DH LASERS MADE BY MELT-BACK METHOD

A buried-stripe configuration of GaInAsP/InP dh laser was made by using a melt-back method combined with a chemical etching for obtaining a mesa-stripe geometry. The wavelength of laser emission was 1.3 μm at room temperature. The lowest threshold current of cw operation at room temperature was 30 mA with the 2-μm-wide buried-stripe laser. External differential quantum efficiency was 24% per facet, and the laser power increased up to 40 mW (dc current of 230 mA) without any significant kink. As the buried-stripe laser had good thermal characteristics, cw operation was realized at 100 ° C in a laboratory atmosphere. When the buried-stripe laser was activated by a pulse current of 3 ns in width, no relaxation oscillation was observed in the pulse response of laser emission, which is considered to be preferable for high-speed modulation of the laser power.