Monolithic integration of an InP-based 4 × 25 GHz photodiode array to an O-band arrayed waveguide grating demultiplexer

We demonstrate the monolithic integration of a uni-traveling carrier photodiode array with a 4 channel, O-band arrayed waveguide grating demultiplexer on the InP platform by the selective area growth technique. An extended coupling layer at the butt-joint is adopted to ensure both good fabrication compatibility and high photodiode quantum efficiency of 77%. The fabricated integrated chip exhibits a uniform bandwidth over 25 GHz for each channel and a crosstalk below −22 dB.