Low threshold 1.51 μm InGaAsP buried crescent injection lasers with semi-insulating current confinement layer

A hybrid growth technique has been used to fabricate low threshold 1.51 μm InGaAsP buried crescent injection lasers with a semi-insulating current confinement layer. The technique involves a first stage of low pressure metalorganic chemical vapor deposition followed by a liquid phase epitaxy stage. The lasers exhibit cw threshold currents as low as 12 mA at 25 °C, high yield, differential quantum efficiency over 41%, and output power more than 18 mW. Small-signal modulation response to 3.5 GHz has been obtained. The lasers show an initial small degradation rate of 1%/kh at 50 °C which gives an estimated operating lifetime of 47 years at 25 °C.