Spectra Information Processing And Software For Near-Infrared Miniature Spectrometer Based On DMD

Along with the development of detection technology, miniature Near-infrared (NIR) spectrometer has been applied in a wide range of fields such as modern scientific experiments, medical science and medicine, industry and agriculture, astronomy monitoring, food safety and so on. NIR spectra processing plays an important role in the miniature spectrometer. This paper focuses on the research for methods of NIR spectra information processing and its application software, based on the miniature NIR spectrometer which was designed and fabricated by Micro-system Research Center of Chongqing University.This thesis carries out research on the relevant key technologies in the subject of NIR spectra information processing after studying the NIR spectra characteristics of miniature spectrometer and its application requirements, puts forward new process ideas and new methods in view of Hadamard Transform based on the DMD; designs the software for the special purpose of the miniature NIR spectrometer, test and verify the whole software system. The main research works are as follows:①Analyze the development situations both home and abroad about the spectra information processing technologies and its application software, according to the requirements of the NIR miniature spectrometer, put forward an overall spectra processing plan using the Lock-in amplifier and the Hadamard Transform based on the DMD along with the characteristics of the NIR spectra.②In order to satisfy the hardware requirements of the NIR miniature spectrometer, a Lock-in amplifier circuit has been designed and fabricated. After the theory discussion, Hadamard transform mask has been calculated and realized by DMD with an order of 63th or 127th.③Determine the whole system scheme of the application software in order to meet the practical requirements of the NIR miniature spectrometer. Design and develop the data acquisition module, spectra preprocessing module, Hadamard transform module and so on based on the VC++ and MATLAB united programming method.④Set up experiment platform to verify the lock-in amplifier circuit and the Hadamard transform function module, result shows that the lock-in amplifier can detect the weak NIR spectra of the miniature spectrometer out of noise and the method of spectra information processing using Hadamard transform based on the DMD can improve the SNR effectively(with a increase ratio of 3.5).⑤Function of the whole software system is tested and the results show that the software using new methods proposed in this thesis can collect the spectrum with less error and the processing of spectra information can get a good result, which in the main satisfy the designed requirements.