Generation and suppression of stray light in UV-vis spectrometer based on micro-silicon-slit

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.