Low-threshold operation of 1.54 μm InGaAsP/InP DFB laser with second-order grating

Abstract
Threshold current has been reduced to 22–35 mA for 1.54 μm InGaAsP/InP distributed feedback (DFB) lasers with second-order grating, and single-longitudinal-mode operation at an output power of 5 mW has been achieved up to 90°C.