Electron-Bombarded CMOS Image Sensor in Single Photon Imaging Mode

Solid-state devices utilizing “photonic events amplification” (PEA) are used for low-level light imaging (LLLI) and are exploited in military, scientific, astronomy, surveillance, and other applications. The PEA imagers are more sensitive by a few orders of magnitude than regular CCD cameras and by an order of magnitude than most sensitive scientific LLLI CCD cameras. The Electron-Bombarded CMOS Image Sensor (EB-CMOS-IS) is a novel PEA technology and has just recently become commercially available. The EB-CMOS-IS technology is a best price/performance combination among concurrent technologies such as EBCCD, EMCCD, Intensified CCD, and Intensified CMOS image sensors. Although the EB-CMOS-IS-based applications demonstrate outstanding sensitivity, they are exploited today far from their maximal potential. In this study, we developed a comprehensive model of the EB-CMOS-IS used for simulation of the sensor performance as a function of the device parameters, e.g., photocathode quantum efficiency, acceleration bias, electrons-to-voltage conversion factor, and operation parameters, e.g., amplifier gain, offset, and exposure time. We selected parameters enabling a single photon imaging (SPI) mode and performed imaging simulations for an object under various low-level illumination conditions. We present a method of the EB-CMOS-IS operation in the SPI mode for low-light-level imaging of a stationary object, boosting the sensor sensitivity to a level better than 10^-7 lux.