Miniature Spectrometer With Low Noise High Dynamic Research

Spectrometers are the basic analysis instruments of optical spectroscope and spectral analysis,especially in the late 80s and MEMS (micro-electro-mechanical -system) technology development. But with a traditional grating spectrometer compared to the dispersion distance as shorter, more compact space equipment, apparatus, resolution, sensitivity, signal to noise ratio performance will rely more on detector,data acquisition and signal processing.This paper on Miniature spectrometer for small grating structure design and the basis for discussion, and focused on:(1) Czerny-Turner spectrometer optical system selection and evaluation of basic parameters, especially the production of silicon using MEMS technology and performance characteristics of slot means;(2) Spectral detection of common drive system design approach to the same hardware simultaneously drive three models CCD detector, maximum simplified circuit design, achieved TCD1304AP type detector integration time 10us ~ 3sec adjustment range, to ensure the system can meet the needs of the majority of practical applications;(3) Part of the software system design not only completed the total control of spectrometer and conventional spectral measurements, also in two interface modes to achieve the secondary development of the dynamic link library, implemented software system extensions, and the overall system has greater practicality and flexibility; (4) Miniature spectrometer software denoising in the analysis, comparison of the FFT and other denoising based on wavelet domain is proposed and implemented a firm threshold filtering denoising method, experimental results show this method to preserve the original signal the same time to achieve the ideal denoising effect, to save acquisition time 4-5 times, get a better effect of the noise and smooth, then remove most of the noise peak at the same time guarantee the accuracy of the signal;(5) Proposed a unified data integration time measurements to improve the dynamic range of detector method. Using this method can not consider changes in the concentration of measured object response generated after selection of integration time, the software automatically selected only the best integration time under the current data can be collected, the data under different integration time conversion formula based transformation to unified data integration time on absorbance calculations.The paper also discusses the different types of stray light on the final test results to the different effects, with emphasis on micro silicon slit of the UV - visible spectrometer defects, the main factors causing stray light cut-off thick and slit edge straightness, etc., and combinations through the dual filter method, successfully achieved a balance of all share the purpose of the energy spectrum.