Monolithically integrated dual-channel coherent receiver with widely tunable local oscillator for 100 Gbps dual-polarization quadrature phase shift keying applications.

We report implementation of a monolithically integrated 100 Gbps dual-polarization quadrature phase shift keying (DP-QPSK) wavelength tunable coherent receiver on a 1  mm×3  mm die that consists of a tunable C-Band local oscillator with a 40 nm range, eight 30 GHz photodetectors, and two parallel 90° optical hybrids. A BER of 10−3 with an OSNR of 7.5 dB operating at 50 Gbps NRZ-QPSK data per channel is reported.