Photon Counting Error Rates in Single-Bit and Multi-Bit Quanta Image Sensors

Photon or photoelectron counting error (bit error) rates are determined for single-bit and multi-bit quanta image sensors (QISs). The results are also applicable to CMOS image sensors with deep sub-electron read noise. The effects of read noise, gain variation, and quanta exposure level on the counting errors (bit errors) in a QIS device are investigated. The interaction of these factors yields complex behavior of the counting error rate. Still, photon-counting is predicted to be remarkably accurate for quanta exposures greater than unity despite read noise and conversion-gain variation, and accurate at very low-light levels if the read noise is less than 0.15e- r.m.s.