Development, testing, and initial space qualification of 1.5-μm high-power (6W) pulse-position-modulated (PPM) fiber laser transmitter for deep-space laser communication

We report on the development, testing and initial space qualification of a 1.5-μm, high-power (6W), high wall-plug efficiency (~15%), pulse-position-modulated (PPM), polarization-maintaining (PM), fiber laser transmitter subsystem for deep-space laser communication links. Programmable high-order PPM modulation up to PPM-128 formats, with discrete pulse slots ranging from 0.5- to 8-nsec, satisfies variety of link requirements for deep space laser communication to Mars, asteroids, and other deep-space relay links, per NASA's space laser communication roadmap. We also present initial space qualification results from thermal-vacuum tests, vibration testing, radiation testing and overall reliability assessment.