The noise performance of electron multiplying charge-coupled devices

Electron multiplying charge-coupled devices (EMCCDs) enable imaging with subelectron noise up to video frame rates and beyond, providing the multiplication gain is sufficiently high. The ultra-low noise, high resolution, high-quantum efficiency, and robustness to over exposure make these sensors ideally suited to applications traditionally served by image intensifiers. One important performance parameter of such low-light imaging systems is the noise introduced by the gain process. This work investigates the noise introduced by the electron multiplication within the EMCCD. The theory and measurements of the excess noise factor are presented. The measurement technique for determining the excess noise factor is described in detail. The results show that the noise performance matches that of the ideal staircase avalanche photodiode. A Monte Carlo method for simulating the low-light level images is demonstrated and the results compared with practical experience.