Low-threshold high-To constricted double heterojunction AlGaAs diode lasers

Abstract

Constricted double heterojunction (c.d.h.) diode lasers of relatively low c.w. thresholds (28–40 mA) are obtained by growing structures that maximise the amount of current flow into the lasing spot. These values are obtained while still using standard 10 μm wide oxide-defined stripe contacts. Over the 20–70°C temperature interval, we find threshold current temperature coefficients as high as 320°C and a virtually constant external differential quantum efficiency.