LED均匀准直光学系统设计

Design of optical system for collimating light of LED uniformly

为了获得均匀准直光,设计了一种LED光学系统。该光学系统由一个全内反射(TIR)透镜和一个自由曲面透镜组成,可以用于水下光通信和水下成像系统的照明。其中,TIR透镜入射曲面将LED发出的球面波准直为平面波然后使之均匀分布;自由曲面透镜将均匀分布的光线转换为平面波。同时,设计了三种不同出射光斑直径的光学系统。经仿真实验表明:该光学系统可以实现大于0.76的均匀度和89%的出射光效(TOE)。为了保持较高的均匀性和出射光效,自由曲面透镜的半径不应小于TIR透镜。

A type of optical system consisting of a total internal reflection （TIR） lens and a freeform lens is designed for collimating the light of LED uniformly. The optical system can be used for under- water light communication and illumination of underwater image system. The TIR lens collimates all the light of LED to a plane wavefront and redistributes it to a uniform pattern, and the freeform lens transforms the uniform light into a plane wavefront. At the same time, three optical systems produ- cing different radius of output light pattern are designed. The result shows that the uniformity of the designed optical system is lager than 0.76 and the total output efficiency （TOE） is larger than 890. It is concluded that the radius of the freeform lens should not be smaller than the TIR lens in order to keep high uniformity and TOE.