宽谱段高分辨扫描光谱定标技术  

Broad band and high resolution scanning spectrum calibration technology

作　　者：迟明波[1] 韩欣欣 徐阳[1] 舒风风 吴一辉[1] CHI Ming-bo;HAN Xin-xin;XU Yang;SHU Feng-feng;WU Yi-hui(State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033,China;University of Chinese Academy of Sciences, Beijing 100049 , China)

机构地区：[1]中国科学院,长春光学精密机械与物理研究所,应用光学国家重点实验室,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《中国光学》2020年第2期249-257,共9页Chinese Optics

基　　金：国家自然科学基金项目(No.61605198,No.6172780105);吉林省科技发展计划项目(No.20180520230JH)。

摘　　要：为了满足原子发射光谱仪在紫外至近红外宽谱段范围内的高光谱分辨率快速检测需求,采用精密角位移平台直接驱动光栅,配合面阵探测器,实现高精度光谱分段快速扫描探测。但在扫描过程中,探测器像元波长增量与光栅转角呈非线性关系,且不同像元的波长增量不同,这对该光谱仪波长定标造成障碍。为校正光栅色散的非线性,基于光栅方程精确计算光栅转角与探测器首尾两端像元波长的映射关系,针对同一光栅转角,探测器其余像元波长利用首尾像元波长按照局部线性色散规律计算得到,从而完成全谱段光谱定标。依据定标所得转角与探测波段对应关系依次驱动光栅转动,实现宽谱段范围内的分段高精度光谱快速扫描探测。利用汞灯光源对该定标方法的波长检测精度进行检验,在200~800 nm的宽谱段范围内,波长准确度优于0.018 nm,波长重复性优于0.001 nm。In order to achieve rapid and high spectral resolution detection in the broad band from ultraviolet to near infrared with an atomic emission spectrometer,an ultra-precision rotation stage is used to drive grating rotation to realize spectral segment-scan with high speed and high precision functioning together with an imaging CCD.However,during the scan,the wavelength increment of detector pixel changes nonlinearly with the angle of the grating,and the wavelength increments of different pixels are different,which becomes an obstacle to accurate spectral calibration.To compensate for the nonlinearity of the grating dispersion,the corresponding relationship between the wavelengths of the pixels at both ends of the detector and the rotational angles of the grating is calculated based on the grating equation while the wavelengths of the other pixels are calculated by using the wavelengths of the pixels at both ends with the linear dispersion law.Thus,with this methodology,the calibration of the full band of wavelength is implemented.After calibration,according to the corresponding relationship between the angle and the detection wavelength band,the grating is driven to rotate successively to realize the spectral segment-scan with high resolution and high speed in broad band.The wavelength accuracy and repeatability with this method are tested by using a mercury lamp.The results show that the wavelength accuracy is better than 0.018 nm and the wavelength repeatability is better than 0.001 nm in the wave band from 200 nm to 800 nm.

关 键 词：光谱仪 光栅色散 色散非线性 波长定标 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]