Single-Photon Counting System Based On A 4h-Sic Avalanche Photodiode

Weak ultraviolet (UV) signal detection systems have broad application prospects in fields such as space science, aerospace, and military communications. 4H-SiC avalanche photodiode (APD) devices have a high internal gain and can be used in single-photon-based UV radiation counting systems when in Geiger-mode operation. The system comprises an APD drive circuit, a passive quenching circuit, a signal conditioning circuit, a counting and control circuit based on a microprogrammed control unit, and a display module, which can perform real-time monitoring of changes in weak UV radiation.