An experimental and numerical study of the impact of ambient light of SiPMs in VLC receivers

Published in MDPI Photonics. It introduces my SiPM simulator, SimSPAD, and validates it against measured results with Monte Carlo experiments. The roadmap paper builds on it.

Abstract

Silicon photomultiplier’s relatively large area and ability to detect single photons makes them attractive as receivers for visible light communications. However, their non-linear response has a negative impact on the receiver performance, including making them particularly sensitive to ambient light. Experiments and Monte Carlo simulations have been used to study this non-linearity. The resulting detailed understanding of the origins of the non-linear response leads to concerns over the accuracy of some previous simulations of SiPMs. In addition, it leads to simple methods to determine the maximum rate at which an SiPM can count photons and of determining the impact of a SiPMs non-linearity on its performance of a receiver. Finally, a method of determining which filters should be used to protect an SiPM from ambient light is proposed.

Key Findings

The paper presents the simulator and the modelling decisions that matter when simulating SiPMs.

Comparing SiPM parameters such as PDE, microcell count, recovery time and output pulse width is best done in detailed simulation. Reliable experiments are hard: commercial SiPMs come in few variants, and other parts of the system affect the results. The simulations agree with experiment, which makes them a sound basis for that comparison.

OFDM links to SiPMs currently use a Volterra series equaliser, which needs many parameters. Monte Carlo simulation could lead to simpler, more effective ways to handle the non-linearity that transmitted data causes.