Range-compensating lens design, implementation and experimental results

Abstract

A range-compensating lens (RCL) design used in the return channel for active optical sensors, e.g., range-finders and LiDARs, has been developed by Mudge [Appl. Opt., 58(28), 7921-7928, (2019)] and detailed using raytrace methods by Phenis et al. [Proc. of SPIE, 11125(111250J), (2019)]. The motivation of the lens is to reduce the return signal with targets (objects) relatively near and boost the signal at far range targets by combining lens elements in parallel rather than in series. Using the techniques provided, a designer can develop a lens requiring a detector with less dynamic range and/or extend the far range limit while maintaining the minimum target distance. We provide a design of a two-element RCL, implementation, and a comparison with experimental results. With this foundational step, further flatting of the return signal curve as a function of range can now be done utilizing a three- or multi-element RCL design.