Multi-channel silicon photonic receiver based on compact second-order microring resonators

A monolithically integrated multi-channel receiver fabricated on the Silicon-on-Insulator (SOI) platform is demonstrated experimentally. This receiver is composed of an eight-channel thermally tunable microring resonator (MRR) filter as the wavelength division multiplexing (WDM) demultiplexer and an array of high speed waveguide-integrated Ge-on-Si photodetectors (PDs) for light detection. Second-order MRRs were utilized in each channel to obtain steeper roll-off from passband to stopband and lower crosstalk. The receiver was fabricated by using CMOS-compatible fabrication process at IME A*STAR. With the thermal tunability, the channel spacing can be adjusted according to different channel grid. Lower than -30 dB crosstalk and higher than 50 GHz 3-dB bandwidth was obtained for the demultiplexer with a channel spacing of 150 GHz. Proof-of-principle demonstration shows that each channel is capable of operating at a data rate of 10 Gb/s, resulting in an aggregate data rate of 80 Gb/s.