Silicon Based Photon Counting Detector Providing Femtosecond Detection Delay Stability

Increasing demand for accurate distance measurement, laser time transfer or better bias control in geodetic measurements motivates the development of solid-state photon counting detectors. We will discuss the design and achieved performance of silicon based single photon avalanche diode detector system. It was optimized for high detection delay stability performance. The existing single photon avalanche diode control circuit was optimized to compensate undesirable properties of the silicon diode to provide minimum temperature dependence of the detection delay, while maintaining its high timing resolution. As a result the detection delay changes typically 6 fs per Kelvin in a temperature range +15 °C to +55 °C. Detection delay is stable within ±1.5 ps over a broad temperature range -55 °C to +55 °C. Achieved timing stability of the entire time correlated single photon counting chain expressed in the form of time deviation is better than 40 fs for integration time of several hours. This extended timing stability finds its application in laser time and frequency transfer between the ground segment and orbiting clocks in space in order to determine the space clock red shift caused by gravity. It will lead to further tests of general relativity beyond previous experiments.