多级共焦抛物面反射式激光扩束系统光学设计

The laser beam expander, which can expand the beam diameter and compress the divergence angle, is widely used in laser ranging, atmospheric detection, and other fields. In order to compress the external dimensions of the laser beam expander and reduce the distance between the output beam and the input beam, a multi-stage reflection laser beam expander composed of multiple confocal off-axis parabolic mirrors is proposed in the paper. According to the design requirements, the system parameters of the multi-stage reflection laser beam expanders are calculated. A single-group beam expander and two multi-stage beam expanders are simulated, and their tolerances are analyzed by ZEMAX optical design software. The dimensions and tolerances of the single-group beam expander and the multi-stage beam expanders are compared. The results show that the multi-stage beam expander can achieve high-magnification laser beam expansion in a shorter distance within a relatively loose tolerance range.