Optical Communication Array Transceiver

Free-space coherent optical communication systems require a single (spatial) mode to mode-match the optical local oscillator (laser) to the incoming optical communication signal. Theuse of low SWaP-C commercial terrestrial telecommunications fiber coupled transceivers (i.e., modems) is a great benefit. Thesingle-mode-fiber coupled receiver core-diameter limits the fiber coupling (and thus overall) efficiency, Fast steering mirror (FSM) control systemsare typically used to insure high coupling efficiency. TheFSM systems require significant electrical power and cost.We propose to eliminate the FSM requirement using two innovations: a flys-eye optics and an optical multimode to single-mode converter (a.k.a., photonic lantern). Further, the flys-eye optics and photonic lantern could potentially reducetelescope optical requirements. In Phase 2, we designed, built and tested a full-duplexoptical communication terminal with a 100 Gbps coherent transceiver and a phased array of 3 telescopes. Replacing the FSMs (3 units) withflys eye receivers will result in lower weight on the gimbal. This reduces the gimbal motor load providing higher control loop bandwidth.
Benefits: Scalable versions of the innovations in the Optical Communication Array Transceiver (OCAT) will enable future data volume returns to and from space missions with return data rates >100 Gbps (cislunar, i.e., Earth to ground), >10 Gbps (Earth-Sun L1 and L2), >1 Gbps/AU2 (deep space), and >1 Gbps (planetary lander). The innovations in OCAT are modular, scalable and extensible or spaceflight systems with concepts for both coherent and direct detection systems. Optical communication networks are complementary to the present RF network. SpaceX, Google, Facebook, Amazon, Airbus and OneWeb etc. are pursuing High Altitude Platform and very large (thousands) LEO satellite constellation for global internet deployment. “The monthly mobile data consumption for video is expected to increase to 38.1 million terabytes by 2021 from 4.4 million terabytes in 2016. Conventional communication satellites will not meet this growing need.