Highly Reliable Transmission System for Next-Generation Optical Access Network Based on Silicon Modulator With Maximum-Ratio Combined Receiver

A novel maximum-ratio combined receiver (MRC-RX) is proposed and demonstrated through a proof-of-concept experiment, conducted to mitigate the system performance degradation caused by the low linearity of the silicon modulator when deployed in passive optical network (PON)-based access. By employing the proposed MRC-RX, an optimized receiver sensitivity is achieved, which enables the mitigation of the performance degradation induced by the silicon modulator, and a more reliable transmission in both cases of low and high received power. In the proof-of-concept experiment, at a bit error rate of 1.0 × 10
^-4
, the receiver sensitivity of the MRC-RX was improved by 3.5 dB and 6.7 dB compared with the lite coherent receiver (lite CO-RX) and direct detection receiver (DD-RX), respectively. Compared with a system employing a commercial lithium niobate (LiNbO3) modulator, a maximum improvement of ~5.6 dB in the receiver sensitivity was obtained for the MRC-RX in the silicon modulator system. Thus, the system performance degradation caused by the low linearity of the silicon modulator can be effectively reduced by employing the MRC-RX. The proposed method makes sense to the building of next generation high reliable photonics integrated access by employing silicon modulators.