手持式拉曼光谱仪探头系统的杂光抑制新方法  

New Approach of Stray Light Suppression for Probe System of Handheld Raman Spectrometer

作　　者：刘兵[1,2] 于凡菊 孙强[1] 刘英[1] 安岩[1,2] 姜承志[1,2] 呼新荣 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049 [3]山东省济宁市邹城第二中学,山东济宁273500

出　　处：《中国激光》2014年第1期213-220,共8页Chinese Journal of Lasers

基　　金：吉林省科技厅项目(20106015;20125092)

摘　　要：手持式拉曼光谱仪的探头系统为光照明和光收集共光路系统,由此产生了除瑞利散射杂散光之外的由于照明激光多次反射的杂散光,成为此类探头系统必须解决的问题。根据获得的实际样机的结构数据,运用实际光线追迹的方法,通过建立合理的杂散光分析模型和理论计算,获得了杂散光聚焦大小和位置、出射方向、到达狭缝处能量大小等信息。根据对杂散光的分析,提出了在探头系统中采用黑点板遮挡杂散光的新方法,并确定了黑点板的大小和位置。光学仿真分析结果表明,此方法对激光反射杂散光的抑制水平达到10-13数量级,满足手持式拉曼光谱仪系统对杂散光的抑制要求。采用黑点板技术,还可以将到达滤光片上的入射角大于2°的约50%的激光反射光滤除。Handheld Raman spectrometer probe system shares the same optical configuration for illumination and light receiving. Thus, stray light caused by multiple reflections of laser, expect for Rayleigh scattering, is a problem to be solved for this kind of probe system. By real ray tracing method, setting up reasonable stray light analysis model and theoretical calculation, we get the total stray light information, together with our actual prototype structural data, such as the size and location of focus, emergent direction, energy in the slit and so on. Then a new approach of stray light suppression for spectrometer probe system that uses black board to block the stray light is proposed. The size and location of the black board are determined according to the analysis of the stray light. The optical simulation analysis results show that the black board suppresses stray light to the level of 10-~3 in Raman spectral region. This satisfies the requirements of the handheld Raman spectrometer. With black board method, almost 50 % of the laser reflection with incidence angle larger than 2° on the notch filter can be filtered.

关 键 词：光谱学 手持拉曼光谱仪 光学探头 弱信号探测 杂散光 黑点板 

分 类 号：O439[机械工程—光学工程]