Cat eye effect weaken based on achromatic prism and phase corrector

Abstract

Sensor surface or division plate of optoelectronic imaging system can retroreflect incident beams energy strongly. This so-called cat eye effect is useful for engineering application, such as range finding. However, it is hazardous for the hidden photoelectric equipment be detected by a laser active device based on cat eye effect. In this paper, we propose a new scheme of geometrical optics imaging system to change the beam incident angle on the detector surface. Thus, the reflected beam energy could pass through a completely different route and be blocked by the lens aperture, so it cannot be reflected back to the active detection device. The aim of anti-detection for the lens design is achieved by usage of prism and phase corrector. A prism plays a role of bending beam direction of propagation to deviate from the optic axis and maintaining the direction of image surface simultaneously. The cemented achromatic prism used herein is to correct the chromatic aberration induced by the prism. And we also adopt a fixed phase corrector to compensate the large amount of oblique astigmatism following a prism in nonparallel beams. A final anti-detection optical imaging lens is shown as example. We offer the detailed design and simulation results, which shows that this kind of optics system can reduce the cat eye reflected signal substantially and maintain acceptable imaging performance.