Method to uniformly diverge a reflected beam with a plano–concave lens located in front of a cube-corner retroreflector

Abstract

The cube-corner retroreflector is widely applied in electro-optical tracking, communication, and interferometers. In some applications, a diverging reflected beam with a uniform intensity is required. A method is proposed to uniformly diverge the reflected beam by placing a plano–concave lens in front of a normal cube-corner retroreflector. The feasibility of the method is demonstrated by the geometrical optics method and diffractive analysis. The influences of the structure parameters of the cube-corner retroreflector and the plano–concave lens on the diffraction characteristics of the reflected beam are investigated. They reveal that appropriate values for the width of the chamfers and the dihedral angle tolerances can be chosen to homogenize the distribution of the reflection beam. Both the geometrical and diffractive optics analysis results indicate that the divergence half-angle of the reflected beam increases quasi-linearly with the growth of the aperture, and the divergence half-angle reduces with the increase of the curvature radius. Therefore, the divergence half-angle can be optimized with the variations of the curvature radius and the aperture of the plano–concave lens.