"Our core product is the Silicon Photomultiplier (SiPM). The SiPM is a solid-state sensor that is closely related to SPADs (single photon avalanche diode). A simplistic description of SPAD is a binary photon-activated ‘switch’. An SiPM is formed of a close-packed array of SPADs with a summed output. This summed-matrix of SPADs, that forms the SiPM, acts as a quasi-analog sensor that retains single-photon sensitivity upon a large surface area.
SiPMs have very high internal gain and therefore do not require external amplification that would contribute additional noise to the signal. Therefore the SiPM will have a better SNR than the APD in many use cases.
The histogramming ToF approach reveals the time-correlated photons that would otherwise be lost in the background noise of the ambient light and is used to extract the distance measurement."