基于黑白光栅的宽波段大视场激光告警

Laser warning with broadband and large field of view based on black-white grating

为了实现激光告警机宽光谱、大视场的高精度探测,提出了一种基于宽波段光栅衍射的大视场二维激光告警探测系统。设计了由宽波段光栅和大视场镜头组成的光学系统,通过采用五组七片式组合透镜结构,实现了水平方向95°、垂直方向72°的大视场探测。镜头的光圈为2.0,入瞳直径为36 mm,保证系统具有很好的通光量。设计加工了光栅常数为2.5μm(占空比为0.6)的宽波段黑白光栅,实现了0.5~1.7μm的宽波段探测。系统中加入多窄带滤光片以滤除背景光的干扰。最后,用典型波长(532,1064,1550 nm)的激光器进行测试,系统探测得到的角度测量误差优于0.7°、激光中心波长的探测精度优于8 nm,通过实验验证了该方法的可行性。

To realized laser-warning systems for high-precision detection with a broadband and large field of view,a wide field two-dimensional laser-warning detection system was presented based on broadband black-white grating diffraction.In addition,an optical system comprising a broadband black-white grating and large field-of-view lens was designed.A five-group seven-element combined lens structure was applied to achieve the large field-of-view detection with an azimuth angle of 95°and a pitch angle of 72°.The lens aperture was 2.0,and the pupil diameter was 36 mm.These values ensured that the system exhibited a considerable amount of light transmission.Furthermore,a broadband black-white grating with a grating constant of 2.5μm(and duty cycle of 0.6)was designed and processed,with broadband detection performed from 0.5-1.7μm.Moreover,a multi-narrowband filter is added to the system to filter out background-light interference.Finally,testing with lasers of typical wavelengths(532,1064,and 1550 nm),the angle error achieved by the system is better than 0.7°,the laser center wavelength detection accuracy is better than 8 nm,thus verifying the feasibility of the method experimentally.