A 25 Gb/s Burst-Mode Receiver for Low Latency Photonic Switch Networks

We report a dc-coupled burst-mode (BM) receiver for optical links in a dynamically reconfigurable network. Through the introduction of interlocking search algorithms, a robust 25 Gb/s BM operation is achieved with 31 ns lock time. At the beginning of the burst, the receiver first performs input dc current offset calibration in 12.5 ns, then achieves phase lock in 18.5 ns, and after that tracks data using a phase interpolator (PI) based bang-bang clock and data recovery (CDR). The sensitivity of the receiver is -10.9 dBm (average power, BER <; 10^-12) at 25 Gb/s, tested with a single mode 1550 nm reference optical transmitter. There is no significant sensitivity penalty in the presence of ±100 ppm frequency offset between the transmitter and the receiver. Measured power efficiency of the receiver at 25 Gb/s is 4.4 pJ/bit. The core of the 32 nm SOI CMOS circuit occupies 200 μm × 300 μm.