Low-current-threshold strip-buried-heterostructure lasers with self-aligned current injection stripes

Abstract
A modified strip‐buried‐heterostructure (SBH) laser is described where the LPE growth process self‐aligns the current‐confining stripes with the active GaAs strips. With these lasers current thresholds have been reduced from ∼180 mA in previous SBH laser to ∼70 mA for active GaAs strips of 380×10×0.2 μm. Excellent linearity in light‐current characteristics and symmetry in laser output from both mirrors were obtained under both pulsed and cw operations. cw operation has been achieved at heat‐sink temperature as high as 115 °C. The current thresholds Ith have an exponential variation with temperature of the form Ith∝exp(T/T0) where T0 was 110 °K. Relaxation oscillation and self‐pulsation was not observed for lasers with clean transverse modes in pulsed response up to current injection levels as high as 4Ith.