We report on an electronic coincidence detection circuit for quantum photonic applications implemented on a field-programmable gate array (FPGA). which records each the time separation between detection events coming from single-photon detectors. We achieve a coincidence window as narrow as 500 ps with a series of optimizations on a readily-available and affordable FPGA development bo... https://www.bekindtopets.com/super-value-Keychron-M4-Wireless-4K-Mouse-flash-choice/