全息窄带带阻滤光片用于拉曼光谱测试仪  

Application of holographic notch filters in Raman spectrometer

作　　者：唐敏学[1,2] 赵艳皎[3] 吴建宏[1,2] 

机构地区：[1]苏州大学江苏省现代光学技术重点实验室 [2]苏州大学信息光学工程研究所,江苏苏州215006 [3]复旦大学先进材料实验室

出　　处：《光电工程》2006年第7期134-139,共6页Opto-Electronic Engineering

基　　金：江苏省高技术研究计划资助项目"光纤光栅相位掩膜技术"(GB2004020)

摘　　要：在测量物质的拉曼光谱时，存在着比拉曼散射光强10^3-0^6倍的瑞利散射光，会严重影响拉曼光谱信号的获取。为此，研制了半宽度分别为18nm（峰值波长532nm）和25nm（峰值波长633nm）、光学密度均大于4的重铬酸盐明胶全息窄带带阻滤光片，并将它们用于由平场光谱仪、CCD探测器和计算机控制系统等组成的小型拉曼光谱测试仪中，以滤除瑞利散射光，获得信噪比较高的拉曼光谱信号。对四氯化碳、乙醇以及丙酮等液体样品进行测量的结果表明，在拉曼光谱测试仪中采用该全息窄带带阻滤光片后，可快速测得待测样品的波数低至217cm^-1的拉曼光谱。The measurement of Raman spectra of matters is seriously affected by the existing of Rayleigh scattering lights, whose intensity is 10^3 to 0^6 times brighter than that of the Raman scattering lights. In order to solve this problem, Holographic Notch Filters （HNFs） were recorded in dichromated gelatin. The half-bandwidth of the HNFs is 18nm （at peak wavelength of 532nm） and 25nm （at 633nm） respectively, and their optical densities were larger than 4. They were used in a compact Raman spectrometer composed of a flat-field spectrometer, a CCD detector and a control system to filter the Rayleigh scattering lights and to get the Raman spectra with high signal to noisy ratio. The Ramman spectra of some chemical samples, such as carbon tetrachloride, ethanol and acetone were measured and analyzed. The experimental results show that by using the HNFs in the Raman spectrometer, the Rayleigh scattering lights can be rejected efficiently and the Raman spectra with a wave number as low as 217cm^-1 of the samples can be obtained rapidly.

关 键 词：全息窄带带阻滤光片 重铬酸盐明胶 拉曼光谱仪 平场光谱仪 

分 类 号：O438.1[机械工程—光学工程]