Towards combined quantum bit detection and spatial tracking using an arrayed single-photon sensor

Experimental quantum key distribution through free-space channels requires accurate pointing-and-tracking to co-align telescopes for efficient transmission. The hardware requirements the sender and receiver could be drastically reduced by combining detection of bits spatial tracking signal using two-dimensional single-photon detector arrays. Here, we apply a CMOS avalanche diode array measure monitor level interference time-bin interferometer while simultaneously position signal. We verify an angular field-of-view 1.28° demonstrate post-processing technique reduce background noise. experimental results show promising future detectors in low-light communications, such as communications.