Highly efficient and athermal 1550nm-fiber-MOPA-based high power down link laser transmitter for deep space communication

We demonstrate highly efficient, 1.5um-fiber-amplifier, optimized for athermal and reliable operation. High efficient operation is sustained for a wide range of pulse-position-modulation (16 to 128-ary PPM) formats with pulse widths varying from 8nsec to 0.5nsec. System achieves 6W average and ~1kW peak power with 8nsec pulses and 3Ghz linewidth. Stimulated Brillion scattering is managed by use of LMA fiber in final stage and precise linewidth control while maintaining the required diffraction limited, and (PER>20dB) polarized output. System maintains performance for ambient temperatures 10-50°C.