Design And Implementation Of Signal Processing System For Optical Fiber Spectrometer

Spectrometer is a basic optical measuring instrument.Through the measurement and analysis of spectral signals,the identification of material structure and composition and the measurement of optical properties of materials can be realized.Spectrometers have been widely used in various fields such as industrial sites,biomedicine,and modern science.Due to the disadvantages of high cost and large volume,traditional spectrometers limit their application scenarios.Therefore,the development trend of spectrometer in China and abroad is toward miniaturization,portable and low power consumption to meet the needs of in-situ and on-site detection..At present,there is still a big gap between the development of portable optical fiber spectrometers in China and foreign countries.Therefore,it is of great significance to develop a portable optical fiber spectrometer with small size,low power consumption,light weight and low cost.The spectrometer is mainly composed of the dispersive optical system,the spectral signal acquisition and the data display and processing on the computer.This paper mainly studies the design of signal detection and transmission module of portable optical fiber spectrometer.The correctness and stability of this part is the guarantee for the stable operation of the whole spectrometer system.According to the technical goals of the system,this paper determines the scheme design and IC selection of the detection circuit module.The detector uses a back-thinned area array CCD sensor,which has the advantages of the high sensitivity,large dynamics range and low noise.Because the output of the CCD sensor is analog signal,it is not conducive to the signal transmission and processing.It is converted into a digital signal sampling circuit,and finally transmitted to the computer for display and analysis through the USB2.0 interface.In addition to spectral detection,it is necessary to detect the temperature and humidity data of the system.The system uses CPLD as the control center,which is responsible for generating the driving timing signals required for the normal operation of each module,and forms the Slave FIFO transmission mode with the USB2.0 control chip CY7C68013 A to complete the stable transmission of data.After completing the principle analysis of the scheme,the scheme is finally determined,and the drawing of the schematic diagram,PCB plate making,code writing,circuit debugging,and joint debugging of the host computer software are completed.The design of the spectrometer signal detection system that satisfies the system specifications is finally completed.