Research On Circuit Design And Calibration Method Of Optical Fiber Spectrometer

Spectrometer is a widely used optical analysis instrument.It is designed based on the principle of spectral dispersion and widely used in industrial production,chemical detection,biomedical,astronomical research and other fields.With the development of scientific research,biomedicine and space exploration,the spectrometer is required to be miniaturized,portable and highly sensitive.However,the relatively mature research results and measurement system in this field are all developed abroad.There is still a big gap between domestic products and foreign products in terms of function and stability.Therefore,the development of high performance,small size,low power consumption,low cost optical fiber spectrometer and its performance parameter measurement system has a good application prospect.According to the requirements of the subject,a fiber spectrometer based on grating splitter module and area array CCD image sensor is developed.The driving and signal processing circuit of the CCD image sensor is designed and implemented.The internal control program of the programmable device CPLD and the firmware program of the USB transmission module are written.The spectrum data is transmitted to the computer in real time through USB interface.According to the image sensor and camera performance test standard EMVA1288 of the European Machine Vision Association,a CCD image sensor and circuit performance parameter test device based on integrating sphere,LED light source,standard detector and computer are designed,and the photoelectric response curve and time of the image sensor are measured.Parameters such as noise,signal-to-noise ratio,dynamic range,dark current and spatial non-uniformity.Finally,the fiber optic spectrometer was calibrated with wavelength and absolute spectral radiance,and the calibration results were verified by experiments and error analysis.The results showed that the wavelength calibration error was less than 0.3nm,and the average error of absolute spectral radiance calibration was 1.056%,which reached the subject Design requirements.