采用MEMS技术,研制了一种基于微硅狭缝的紫外-可见光谱仪。介绍了该光谱仪的系统组成,分析了其杂散光的产生原因,着重讨论了光谱仪的关键部件-微硅狭缝的直线度、厚度与杂散光之间的关系,并对狭缝直线度产生的杂散光进行了实验验证。针对以卤钨灯为光源的紫外-可见光谱仪进行测量时,紫外部分能量低,杂散光严重的问题,提出一种组合滤光片法,通过在入射狭缝前和探测器前增加双重滤光片,平衡紫外-可见光范围内各谱段的光波强度,抑制紫外波长处杂散光的影响。实验结果表明:采用组合滤光片法抑制杂散光后,杂散光降低为抑制前的23%。
A UV-visible spectrometer based on a micro-silicon-slit was developed by using the Micro-electro-mechanical System(MEMS) technology.The generated reasons of the stray-light from the UV-visible spectrometer were analyzed and the relationships between the straightness and thickness of micro-silicon-slit with the stray-light were discussed.Then,an experimental verification was carried out for the stray-light caused by the slit straightness.Furthermore,a new combining filter method was proposed to solve the problem that the radiation power of UV region is much lower than that of visible light region and it is seriously affected by the stray-light when the spectra are measured by a spectrometer with the halogen tungsten light source.The method combines a neutral density filter and a balanced filter in the front of the micro-silicon-slit and the detector to balance the radiation powers of different spectral regions and to inhibit the stray-light of UV spectrometer.It is shown that the stray-light of the UV-visible spectrometer has been reduced by 23% as compared with that by using the traditional method.