Studey Of The Key Technology Of The Micro Fourier Transform Spectrometer In Visable-near Infrared

The spectrometer present a trend of microminiaturization in recent years along with the improve of the demand of the market and the development of microfabrication technology. In this paper, a new micro-Fourier transform spectrometer(FTS) working in the visible-near-infrared band is studied, which is based on space modulation. A conventional Michelson-interferometer with the reflect mirrors replaced by micro-multi-step mirrors is used as beam splitting and interference system. Different optical path differences (OPD) are produced by different mirror facets, which eliminates the moving mirror scanning system and changes the modulation mode from time modulation to space modulation. Without moving parts,this spectrometer has advantages such as compact structure, good stability and high real-time.On the foundation work of design of the structure of the micro FTS, we simulated the work of the micro FTS with ASAP and Matlab software, and optimazed the structure of the micro FTS after the analysis of the simulation. We modulated the effect of difraction and adjusted the size of beam splitter. We modulated and analysed the effect of the surface roughness of the micro-multi-step mirrors, and hereby decided the biggest roughness that can be tolerated by the system,which provided the standard surface roughness of the micro-multi-step mirrors. We study the effect of the of the diffraction on the intensity distribution in the interferogram, and analysed noise introduced by the interrupt of the continuum of the differection effect on the edge of the interferogram. We advanced the method to eliminate the noise and modulated some examples to prove it. Three methods to fabricate the micro-multi-step mirrors are put forward based on the design of the structure:anisotropic wet-etching of silicon and the deposition of multilayers in fixed areas. Expriments of each methods are designed and carried out and results are analysed. The method of anisotropic wet-etching of silicon and deposition of multilayers in fixed areas are chosen after thoughtful considerations. Many experiments are carried out to determine the condition of the experiment, and micro-multi-step mirrors is at last fabricated.