The Design Of Micro-Spectrometer Based On Mems Micromirror

Spectrometer as a precision optical instrument has a very wide range of applications in industry,agriculture,medicine,military,environmental pollution,food safety,scientific research,etc.,due to its high precision,wide detection range,high sensitivity and high reliability and other advantages.The MEMS micromirror is a very small reflector that can be adjusted in one-or two-dimensional direction.MEMS micromirror is one of the important devices of different miniature optical systems.It can effectively overcome the shortcomings of traditional spectrometers,such as high cost,large volume,insufficient portability and popularity.This paper studied and designed a spectroscopy system based on MEMS micromirror,taking advantage of the small size,high degree of freedom and low cost of the MEMS micromirror.Firstly,the pros and cons of different optical systems have been analyzed.According to the requirements of this project,the finally optical system based on MEMS micromirror and the Littrow optical path has been designed.Secondly,the working principles of MEMS micromirror,the blazed grating,detector and other relevant devices have been analyzed.The parameters of the main optical devices have been determined.Third,we selected and ordered the most suitable optical devices according to the parameters,after comparing a number of companies and manufacturers.Fourth,the feasibility of the optical system is analyzed by optical simulation software.Fifth,the power supply circuit of MEMS micromirror and detector have been designed and welded.The actual optical system has been built.The tricks of optical adjustment have been described.Finally,using the relevant equipment such as EE1643 C,YB3202,DS5022 M,HP8000,etc.,the spectral measurement system has been built.UltraScope software has been used to collect the detector signal.Using this system,the spectral characteristics of violet and red diode lasers with central wavelengths of about 401 nm and 648 nm were measured.The results were compared with those of other commercial spectrometers.The main factors affecting the performance of the spectroscopy system and the solutions are discussed.The transmission spectra of methylene blue solution with different concentrations were measured by this spectral analysis system.The results showed that the concentration of solution was gradually changed.Based on the above design method,the design of MEMS micromirror spectrometer is completed in this paper.The results show that stable measurements can be obtained at wavelengths of 390 nm to 710 nm with an average spectral resolution of 30 nm.This result can meet some of the spectral analysis requirements.By selecting different light sources and detectors,we can further expand the measurement range of the spectral system.