Transmitter and fine pointing system development and testing for the CubeSat Laser Infrared CrosslinK (CLICK) B/C mission

Abstract

The CubeSat Laser Infrared Crosslink (CLICK) B/C mission seeks to demonstrate laser crosslinks for full-duplex communications and two-way ranging and time-transfer between two 3U CubeSats: CLICK-B and CLICK-C. Laser crosslinks between satellites can provide enhanced performance, with high data transfer rates and high precision range and timing information, using low size, weight, and power (SWaP) optical transceiver terminals. CLICK-B and CLICK-C will demonstrate laser crosslinks with data rates of at least 20 Mbps over separation distances ranging from 25 km to 580 km. CLICK-B/C will also demonstrate a ranging precision of better than 50 cm and a time transfer precision of better than 200 ps single shot over these distances. We present the design and development status and recent testing results of the laser transmitter and fine pointing, acquisition, and tracking (PAT) system, which are key to achieving these capabilities. The 1550 nm laser transmitter follows a master oscillator power amplifier (MOPA) design using an erbium-doped fiber amplifier (EDFA) for an average output power of 200 mW. A semiconductor optical amplifier (SOA) is used to achieve the pulse position modulation (PPM), ranging in order from 4 PPM -128 PPM. The PAT system uses a microelectromechanical systems (MEMS)-based fast steering mirror (FSM) for fine pointing. A quadrant photodiode (quadcell) provides feedback for the actuation and steering of the FSM.