A 50-Gb/s High-Sensitivity (−9.2 dBm) Low-Power (7.9 pJ/bit) Optical Receiver Based on 0.18- \mu m SiGe BiCMOS Technology

A 50-Gb/s optical receiver (RX) based on 0.18- \mu \text{m} SiGe BiCMOS technology was fabricated and evaluated. To improve the horizontal eye opening and sensitivity of the RX without degrading its power efficiency, it is configured with a two-stage pre-amplifier with high gain (56 dB \Omega ) and high bandwidth (35 GHz), a high-accuracy automatic decision-threshold control (ATC) consisting of power-supply variation and offset cancellers for improving sensitivity, and a jitter-reduction packaging structure for improving transimpedance flatness. The RX achieves high sensitivity of −9.2 dBm, while its power consumption is 7.9 pJ/bit at a data rate of 50 Gb/s. In 50- and 56-Gb/s transmission tests through a 100-m multi-mode fiber (MMF), it demonstrated error-free operation at the bit error rate (BER) of less than 10-12 with the sensitivities of −9 and −6.1 dBm optical modulation amplitude (OMA). It also demonstrated 300-m error-free MMF transmission (at 50 Gb/s) with the practical sensitivity of −7.6 dBm OMA.