Photon counting detector for space applications optimized for both gated and non-gated operation

We are reporting our results in research and development in the field of avalanche semiconductor single photon detectors and their optimization for the selected space projects. Our goal was a development of a solid state photon counting detector capable of high precision photon arrival time tagging. For the application in laser time transfer via satellite the detector should be able to operate in both gated and non-gated modes; additionally the extremely high background photon flux should not disable the detector operation. We have developed the novel active quenching and gating electronics circuit, which enables both the gated and non-gated operation of the K14 Single Photon Avalanche Diode (SPAD). The performance of the optimized photon counting detector has been verified in a series of indoor calibration tests. The detection probability, timing resolution and detection delay stability have been measured in both operation modes under various background photon flux conditions. The detector design and construction is a promising candidate for the space project of Laser Time Transfer prepared by China. The experimental results are presented.