Recently, we have looked into actively quenched SPADs and their detection statistics in time. SPADs are nontrivially affected by recovery time, afterpulsing, and twilight pulsing. We modelled the SPAD behaviour under continuous illumination and calculated the mean count rate as well as the distribution of the number of detections in a time window.
You might also be surprised to learn that SPAD recovery time is not constant. It changes with incident rate.
Check out the full article and supplement in the Journal of Lightwave Technology. The code for numerical computation and simulations is available on CodeOcean and GitHub. Let us know if you have any questions or comments!
SPAD Counting Model