Photon-counting single-pixel camera based on a fast spinning coding disk

Spinning coding masks, recognized for their fast modulation rate and cost-effectiveness, are now often used in real-time single-pixel imaging (SPI). However, in the photon-counting regime, they encounter difficulties in synchronization between the coding mask patterns and the photon detector, unlike digital micromirror devices. To address this issue, we propose a scheme that assumes a constant disk rotation speed throughout each cycle and models photon detection as a non-homogeneous Poisson process (NHPP). This effectively resolves synchronization problems and compensates for speed fluctuations. To validate this method, we designed and fabricated a single-pixel camera prototype that can capture images under an illumination of less than one photon per pixel, with a modulation rate of approximately 100 kHz and an imaging speed of 28 frames per second. The camera is compact, lightweight, and low cost and should find many practical applications for imaging under extremely low-light conditions.