近红外空间外差拉曼光谱仪研究  

Research on Near-infrared Spatial Heterodyne Raman Spectrometer

作　　者：范博昭 冯玉涛(指导)[1] 王荃 高驰 吴阳 韩斌 畅晨光 李娟[1] 李奕儒 赵珩翔 傅頔 FAN Bozhao;FENG Yutao;WANG Quan;GAO Chi;WU Yang;HAN Bin;CHANG Chenguang;LI Juan;LI Yiru;ZHAO Hengxiang;FU Di(Xi'an Institute of Optics Precision Mechanic of Chinese Academy of Sciences,Xi'an 710119,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西安光学精密机械研究所,西安710119 [2]中国科学院大学,北京100049

出　　处：《光子学报》2022年第5期310-319,共10页Acta Photonica Sinica

基　　金：国家自然科学基金(No.41005019);中国科学院西部青年学者(No.XAB 2016A07);陕西省自然科学基础研究计划(No.2019JQ-931);中国科学院西部之光交叉团队(No.E1294301)。

摘　　要：针对微弱拉曼散射光信号的高灵敏度探测需求,使用830 nm的激发光源,对空间外差拉曼光谱仪进行全系统的设计与仿真,并通过研制的光谱仪样机开展拉曼光谱探测实验,其有效光谱分辨率可达3.35 cm^(-1)(矩形函数切趾),实际可探测的拉曼位移范围为171.01~2048.19 cm^(-1)。对不同物体形态、不同拉曼活性的样品进行拉曼光谱探测实验,其中强拉曼活性物质碳酸钙粉末、硫酸钙粉末、硫酸钾粉末的主拉曼光谱峰信噪比均大于370,弱拉曼活性物质甘油、75%酒精溶液、葡萄糖粉末的主拉曼光谱峰信噪比均大于40。实验结果表明830 nm激发光源波长的空间外差拉曼光谱仪系统对多种测试样品均可以获得清晰、准确的拉曼光谱图,具有高灵敏度、高稳定性的拉曼光谱探测能力。Spatial Heterodyne Raman Spectroscopy(SHRS)is a new type of Raman spectroscopy detection technology,which has the advantage of high throughput,high spectral resolution,high sensitivity and no moving parts.SHRS can meet the high-sensitivity detection requirements of weak Raman scattered light,and can also obtain clear and sharp Raman spectra.For Raman spectrometers,fluorescence is an inevitable background signal.The fluorescence intensity and the Raman intensity are approximately inversely proportional to the fourth power of the wavelength,so the excitation wavelength of near-infrared light has lower fluorescence than visible light.The excitation wavelengths of near-infrared light are mostly 785 nm,830 nm and 1064 nm,of which the shorter 785 nm has larger fluorescence.Although the 1064 nm excitation light has a weaker fluorescence,it requires the near-infrared InGaAs focal plane.Compared with visible detectors,it has higher noise,lower sensitivity and resolution.Therefore,this article chooses the wavelength of 830 nm as the excitation light for Raman spectroscopy detection,and its fluorescence is lower than that of 785 nm.On the other hand,the visible detectors can be used for highsensitivity detection.For the excitation wavelength of 830 nm,this paper designs,simulates,develops and tests SHRS.The Littrow wavelength of the spectrometer is 842 nm,the theoretical spectral sampling interval is 2.96 cm^(-1),and the theoretically Raman shift range is 171.71~3031.04 cm^(-1).The spatial heterodyne interferometer adopts integrated adhesive technology.To increase the throughput,the fieldwidened prisms are added to the interferometer.The field angle tolerance of the interferometer is selected to be±2°to ensure the contrast of the interferogram in actual work,and the corresponding contrast of the ideal interferogram is better than 0.98.The fringe-imaging lens group selects a double telecentric lens group with a magnification of 1.The telecentric configuration guarantees the uniform illumination of the image surface,and the

关 键 词：光谱学 拉曼光谱 空间外差 光学设计 信噪比 

分 类 号：O433.4[机械工程—光学工程]