Low‐threshold InGaAs/GaAs strained layer single quantum well lasers with simple ridge waveguide structure

Abstract
Double heterostructure InGaAs‐GaAs strained‐layer single quantum well ridge waveguide lasers grown by molecular beam epitaxy were fabricated by using in situ laser monitored reactive ion etching to form the ridges. Continuous‐wave threshold current as low as 3.5 mA was obtained on a ridge laser diode of 3.3 μm wide and 215 μm long having cleaved mirrors. The lasing wavelength is at 0.988 μm and the measured differential external quantum efficiency is 61%.