Silicon Photomultiplier (SiPM) Selection and Parameter Analysis in Visible Light Communications

A silicon photomultiplier (SiPM) can potentially be used to create the most sensitive optical receiver in visible light communications (VLC) since it contains a large array of microcells and each microcell is capable of detecting individual photons. However, after a single photon is detected, the associated microcell needs a period of several nanoseconds to recover and any photons arriving at the microcell during this period cannot be detected. This effect creates a non-linear response and also introduces a unique form of interference when the transmission data rate is high. In this paper, by analyzing the performance of different models of commercially available SiPMs, we study how the SiPM nonlinearity is related to various SiPM parameters and also show how a VLC transmission link is affected by this nonlinearity. Based on simulation results, we show that a good SiPM detector for VLC applications should have a large detective area so that the overall received optical power is high. At the same time, the size of individual microcells needs be small so that the recovery period is short. Moreover, in this paper, a specially designed receiver consisting of four parallel SiPMs is considered and it is shown that this receiver can support orthogonal frequency-division multiplexing (OFDM) modulation for a wide range of irradiance levels.