Design of refractive spline surface for generating required irradiance distribution with large angular dimension

Abstract

A method is suggested for the design of a refractive optical surface intended for the generation of a prescribed irradiance distribution. The method is based on the gradient optimization of the refractive surface represented as a bicubic spline in spherical coordinates. The optical elements that produce the uniform irradiance distribution in the elliptic and rectangular regions for point and extended light sources are computed. The energy efficiency of the optical elements is more than 73%; the nonuniformity of the generated irradiance distribution is less than 7.5%. The ratio of the illuminated region size to the thickness of the optical system is about 6.5. This value is twice as large as that for optical elements presented in other available publications.