Research On Data Processing System Of Elasto-optic Modulation Interference Based On FPGA

Photo-elastic modulation Fourier transform spectrometer(PEM-FTS)has been used more and more in space exploration,military and other spectral detection fields due to its advantages of high measurement speed and wide spectral range,and has a good development prospect.Because of the high modulation frequency of the elasto-optic modulator,PEM-FTS requires a fast data processing method to process the interference data and reconstruct the spectrum.In this paper,field programmable logic gate array(FPGA)is used as the core processing chip for a series of interference signal processing,so as to invert the spectrum.Firstly,according to the characteristics of interference data of PEM-FTS,some processing methods are analyzed and implemented.Because the optical path difference of the interference signal generated by PEM-FTS is nonlinear,equal time interval sampling will cause the optical path difference nonlinearity,and it cannot directly reconstruct the spectrum by fast Fourier transform,so it is of great significance to study the fast spectral restoration algorithm of PEM-FTS.In order to reduce the bounced light modulation interference signal spectrum of the inversion of the deviation,improve the speed of processing play light modulation interference data and optimize the structure of a data processing system,analyzed the principle of nonuniform fast Fourier transform algorithm,and based on field programmable logic gate array(FPGA)for nonlinear interference signal rapid spectral inversion algorithm implementation;The data processing method and data storage and display method are analyzed and studied by using the structure of the data processing system based on FPGA.The spectral effect of the basis restoration method is analyzed.The simulation results of Modelsim show that the spectral restoration effect of simulated laser interference signal is good,which basically meets the requirements of spectral restoration accuracy and runs fast.Finally,The implementation effect of this design is verified at the board level by Signal Tap Logic Analyzer.