激光告警系统中小型静态傅里叶变换光谱仪的研究  

Study on Miniature Static Fourier Transform Spectrometer Used in Laser Warning Receiver

作　　者：田二明[1,2] 张记龙[1,2] 李晓[1] 张悦[2] 王志斌[1] 

机构地区：[1]电子测试技术国家重点实验室,山西太原030051 [2]山西省光电信息与仪器工程技术研究中心,山西太原030051

出　　处：《光谱学与光谱分析》2009年第3期853-857,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(60572019);山西省青年科技研究基金项目(2007021019);重点实验室基金项目(9140C1204070709);中北大学青年基金项目资助

摘　　要：相干激光告警接收机较光谱识别型激光告警接收机有着不可比拟的优点,在相干激光告警中实时可靠地获取敌方来袭激光的光谱细节具有重要意义。文章介绍的基于等效斜楔干涉具和线阵CCD的小型静态傅里叶变换光谱仪,是相干激光告警接收机的重要组成部分,其光学部分由一个等效斜楔干涉具和柱面镜组成,内部不含扫描部件,具有体积小、成本低、结构简单、性能稳定、光谱检测速度快等优点,可以满足脉宽大于等于10 ns脉冲激光信号光谱高速探测的要求。该光谱仪波长范围从400到1 100 nm,波长分辨率小于10 nm。文中详细介绍了该光谱仪的设计方法和关键光学元件的设计原理,进行了相关的性能分析,构建了实验系统,应用该实验系统对7个中心波长分别为635,650 nm等的半导体激光器进行了光谱测试,并将测试结果与使用日本Advantest公司的Q8344A型光谱仪测得的结果进行了比较,得到中心波长平均误差为0.269 nm,绝对平均误差为0.919 nm。波长分辨率最小为1.170 nm,最大为8.845 nm,且有较高的信噪比。A miniature static Fourier transform spectrometer （MSFTS） as the component of coherent discriminating laser warning receiver （CDLWR） was designed in the present study by using a modified wedge interfering etalon （MWIE）, a linear charge couple device （CCD） and a fast digital signal processor （DSP）. The MSFTS possesses some advantages such as small volume, low cost, high speed, stable performance and good signal to noise ratio. MSFTS can detect the spectrum of HIPL, the short pulse width of laser is about 10 ns, and the spectrum scope is from 400 to 1 100 nrn, The key element of MSFTS is MWIE which is composed of two triangle prisms, one of which is a right angle prism with two equal acute angles of 45°, another prism has no right angle, one of the acute angles is 45°, and another is slightly smaller than 45°. The long sides of the two prisms were bonded by transparent glass glue, and the adhesive surface is plated with special material which serves as a beam splitter （BS）. The incident laser will be split into two equal strength beams with continuously changing optical path difference, the two beams will interfere and form interferogram which will be focused by a cylinder as a line and transformed as s electronic signal by CCD. The electronic signal was processed by using a DSP, and finally we obtained the spectrum of the incident hostile laser by applying fast Fourier transform （FFT）. We have established the experiment system of MSFTS, and used the system and the spectrometer Q8344A made by Advantest Company in Japan to measure the spectra of the seven lasers with different central wavelengths： 635, 650, 670, 780, 808, 850 and 980 nm. The measurement result shows that the worst wavelength resolution is 8. 845 nm at 1100 nm, the best wavelength resolution is 1. 170 nm at 400 nm, the relative average error of central wavelength is 0. 269 nm, the absolute average error is 0. 919 nm and signal-to-noise ratio of our experiment system is better than that of Q8344A.

关 键 词：窄脉冲激光 傅里叶变换光谱仪 等效斜楔干涉具 激光告警 

分 类 号：O433.1[机械工程—光学工程]