Optical system design of an elliptical-hyperbolic lens set for semiconductor laser beam shaping and collimating a hollow beam

In order to solve the problem of energy loss at the center of the Cassegrain antenna, an optical system based on an elliptical-hyperbolic lens set is innovatively designed in this paper, which can shape and convert the elliptical divergent beam emitted from a semiconductor laser into a collimated hollow beam. The system consists of a lens set for collimating and shaping (C-S lens set) the laser beam and a lens set for the generation of a collimated hollow (C-H lens set) beam: the C-S lens set is responsible for shaping the elliptically divergent beam into a collimated circular beam, and the C-H lens set is used to generate a collimated hollow beam. The simulation results show that when the output beam diameter is 17.33 mm, the C-S lens set reduces the ratio of beam waist (RBW) from 1.554 to 1.014, and the standard deviation of the edge beam radius samples (SDRS) decreases from 4.227 to 0.0866 mm. The transmission efficiency of the optical system is 92.28% at 1550 nm, and the broad-spectrum performance is maintained after taking into account the practical loss factors.