Multibeam Beacon Laser Assembly

An optical assembly that combines the output of mutually incoherent lasers into a multibeam source for transmission into free space was designed, assembled, and tested. This design was motivated by the need for ground-based beacon sources required for broadcasting laser beams to spaceborne, satellite-to-ground free-space optical communications systems. These beacons will provide a pointing and tracking reference for the spaceborne optical communications system and be used to uplink commands and data to the spacecraft. The assembly was field tested by broadcasting the beams through a 0.6-m-aperture telescope over a mountaintop-to-mountaintop 45-km atmospheric path, with receiving sensors located at the other end. The key advantages of the design are the following: