A Novel CMOS SPAD Receiver for Optical Wireless Communication

Single-photon avalanche Diodes (SPADs) are widely considered to have promising prospects in the field of optical wireless communication (OWC). In this paper, a novel SPAD-based optical sensor was designed, fabricated, and tested for the application of an OWC receiver. In the application of SPAD-based OWC, intersymbol interference (ISI) effects can be a challenge to improve the performance of SPAD receivers. Therefore, this SPAD sensor was integrated with two unique timing control modes: the clock-driven (CD) mode and the time-gated (TG) mode to reduce the ISI effect in different communication conditions. The bit error rate (BER) testing results showed that our $4 \times 4$ SPAD receivers exhibited high sensitivity, achieving a BER of $3.8 \times {{10}^{ - 3}}$ at a signal power of 71 dBm and a background optical power of 84 dBm. Additionally, by comparing test results with simulation results, we can observe a high degree of congruence between experimental outcomes and simulated results.