Toward High Power Laser (HPL) Optical Communication

CTEC is developing a second version of M-FSM45 Fast Steering Mirror, dedicated to High Power Laser (HPL) spacecraft Optical Communication. The M-FSM45-HPL is benefitting from a total redesign, in order to cope with [50W-80W] laser continuous power range, under space vacuum. The M-FSM45-HPL shall then allow high power Feeder Link applications, for both low earth altitude and geostationary spacecrafts. Whereas the M-FSM45 design has been optimized for production cost-efficiency required for large-scale constellations with FSM quantities > 500-1000 units, the M-FSM45-HPL is optimized for safe long life with very high reliability and for management of laser power applied on the mirror.

The new design includes coil redundancy to connect one single unit to two drive electronics, as well as advanced mechanical end stops on optical moving part, for very high vibrations and shocks loads.

The high-power laser range targeted over nonstop continuous operation has required a drastic thermal optimization by conduction, and enhanced heat sinking via mechanical interfaces, in order to drain the residual Laser heat power induced by the mirror reflectivity > 99,5% at high temperature. The M-FSM45-HPL is soon to be tested in 2024 thanks to the COOP project, funded by CNES and France Relance.