Design and Performance of a Multi-mode Photon-counting Receiver for the NASA O2O Mission

The NASA Orion O2O mission was designed and tested to support high-rate bi-directional optical communications between one of multiple ground sites and a crewed capsule during a 10-day mission. This paper focuses on the design and performance of the receiver that will be based at the NASA White Sands Complex, New Mexico, USA. The main receiver components consist of two 40-cm apertures, each coupled to a specialty multi-mode optical fiber; each fiber coupled to a custom array of superconducting nanowire single-photon detectors; a high-speed, high-channel-count time-to-digital converter; and custom digitizing electronics to perform deserialization, demodulation, clock recovery, and forward error correction with a powerful serially-concatenated pulse-position-modulation turbo code. We show error-free data communication performance up to the maximum required data rate of 267 Mb/s.