新型双通道日夜滤光片的设计与镀制

Novel Type of Dual Channel Band-Pass Day/Night Optical Filter

红外相机和监控系统在日夜成像时使用日夜滤光片代替红外截止滤光片,以保证白天成像无色差,同时晚上能成黑白像。本文采用Essential Macleod软件设计新型双通道日夜滤光片光谱。光谱中440~640 nm的平均透射率大于90%,650~1100 nm波段截止,红外截止区域在940 nm存在带通,其平均透过率小于20%,带宽小于40 nm。采用离子束辅助电子束蒸发的方法,通过优化工艺参数、减小膜层误差,制备得到满足设计要求的K9玻璃基底双通道日夜滤光片。

A novel type of dual channel band-pass,day/night optical filter was developed to make it possible for the infrared night-vision camera and monitoring system to record black/white images at dark night,and to take pictures without chromatic aberration in broad daylight.The newly-developed filter was designed with the assistance of the software package,Essential Macleod.The average transmittance of the filter was estimated to be over 90% in the 440~640 nm range,with the cut-off band from 650 nm to 1100 nm.A band-pass around 940 nm,with bandwidth of 40 nm and an average transmittance below 20%,was found to exist in the infrared cutoff region.The prototyped multi-layered filter was successfully fabricated by ion assisted electron beam evaporation on K9 glass substrates under optimized conditions.Satisfactory results were obtained in the tests of the filter.