1.3-μm GaInAsP/InP buried-ridge-structure laser and its monolithic integration with photodetector using reactive ion beam etching

A 1.3 μm GaInAs/InP BRS laser is monolithically integrated with a photodiode. reactive ion beam etching technique (RIBE) is used for the realization of the laser mesa stripe and for the separation of the laser and the photodetector sections. Influence of the laser-detector gap width, the detector facet inclination, and the laser beam waist on the coupling efficiency between LD and PD are discussed theoretically and experimentally. Coupling efficiency as high as 50 μA/mW is obtained by optimizing the structure. A packaged pigtailed integrated LD-PD is realized, in which the signal emitted from the rear laser facet is detected by the integrated photodiode and used to stabilize the laser output power, through a hybrid feedback circuit, to within 0.1% over 55°C temperature range