Wide Locking Range and Multi-Channel Clock Recovery Using a Silicon Microring Resonator

An all-optical clock recovery (CR) scheme with wide locking range is demonstrated, based on a silicon microring resonator (MRR) and a semiconductor optical amplifier (SOA). The MRR with a free spectral range of 40 GHz works as a comb filter, which removes the modulation information, whereas the SOA operating in the saturation regime performs amplitude equalization to achieve a good optical clock signal. The design of the MRR is investigated according to the tolerance of the subsequent equalizer. Based on the fabricated MRR, single and dual channels CR from 40 Gb/s input data streams can be achieved successfully with root mean square time jitter of ~ 900 fs. Because of the moderate finesse of the MRR, the CR can be achieved with a wide range of several gigahertz.