Study On Accurate Wavelength Calibration For Miniature Spectrometer And Its Application

Spectrometer,as an important optical measuring instrument,is widely used in scientific research,environmental monitoring,industrial detection and other fields.However,the traditional spectrometer is often unable to meet the requirements because of its large volume,high price and other factors.With the continuous development of micro-electronics technology and mechanical processing technology,spectrometer is also developing towards the direction of miniaturization,intellectualization and convenience.Wavelength calibration is an important calibration process before the use of spectrometer.The calibration accuracy will directly affect the measurement accuracy of miniature spectrometer.In this paper,the accurate wavelength calibration method is studied based on the microspectrometer system.Firstly,after reading a large number of previous research literature,two main wavelength calibration methods are summarized,namely wavelength calibration method based on system parameters and wavelength calibration method based on polynomial fitting.For wavelength calibration method based on polynomial fitting,the key factors affecting wavelength calibration are analyzed,including noise,bandwidth and overlapping peaks.For noise phenomena,Savitzky-Golay smoothing filter and wavelet denoising method are compared;For the influence of bandwidth,three different bandwidth correction methods are studied;For overlapping peaks,automatic peak-finding method is used to process;Finally,wavelength calibration coefficients are obtained based on third-order polynomial fitting.Based on the above process,the author proposes a precise wavelength calibration method for micro-spectrometer.In addition,the development of hardware system and software system of the prototype of micro-spectrometer are introduced.The method of precise wavelength calibration is tested in the Lithium-Potassium measurement system.The experimental results verify the validity of the calibration method.