Research of the optical coupling unit for the transmitting terminal of intersatellite optical communication system

The laser diode-coupling unit is an important part of an intersatellite optical communication system.In terms of the requirement of the intersatellite optical communication system,a new coupling method was proposed,in which an aspherical cylindrical lens,whose front cylindrical lens is orthonormal to its back cylindrical lens,was used to collimate the laser beam,and then the beam was focused by a GRIN lens and coupled to a single-mode fiber.How the coupling efficiency changing with the fiber position displacement and fiber axial angle variation was studied,and it was found that the coupling efficiency was insensitive to both the above parameters.Furthermore,the optical power versus the driver current at the end of the fiber was tested,and 80mW output power was obtained,which showed the optical unit satisfied the designed request.