High-sensitivity inter-satellite optical communications using chip-scale LED and single photon detector hardware

Small satellites have challenging size weight and power requirements for communications modules, which we address here by using chip-scale light-emitting diode (LED) transmitters and single-photon avalanche diode receivers. Data rates of 100 Mb/s have been demonstrated at a sensitivity of -55.2 dBm, and simulations with supporting experimental work indicate ranges in excess of 1 km are feasible with a directional gain of up to 52 dBi and comparatively modest pointing requirements. A 750 m, 20 Mb/s link using a single micro-LED has been demonstrated experimentally. The low electrical power requirements and compact, semiconductor nature of these devices offer high data rate, high sensitivity communications for small satellite platforms.