Monolithic InP Multiwavelength Coherent Receiver Using a Chirped Arrayed Waveguide Grating

We propose and demonstrate a novel four-channel monolithic polarization-diversity dual-quadrature coherent receiver with balanced detection in InP. It uses an interleave-chirped arrayed waveguide grating that acts simultaneously as a demultiplexer, four polarization splitters, and four 90° hybrids. There are no waveguide crossings, and the polarization extinction ratio is >;21 dB and the hybrid phase error magnitude is <; 1° without any post-fabrication adjustments. We demonstrate 4×43-Gb/s reception.