Compact silicon differential receiver with integrated zero biased balanced detection

We present an optimized differential receiver in silicon with a minimized footprint and balanced zero biased Ge photodiodes. The receiver integrates a delay-line with a 2×4 MMI 90 degree hybrid and two balanced photo diodes for DQPSK demodulation. Also a tunable power splitter is included for better balancing. Two receivers were tested, for 10Gbps and 20Gbps operation, and well opened eye-diagrams were measured.