The Signal Acquisition And Analysis In Surface Plasmon Resonance System Of Optical Fiber

After the discovery of SPR(Surface Plasmon Resonance) effect, it is taken as a new analysis technology and has been widely used in the life science, physical and chemical,virus detection and other fields. The optical fiber SPR, which possesses the advantages of small size, low cost, ease of integration etc, has great market prospect and research value.So this makes the optical fiber SPR signal acquisition and processing extremely important.In this research, an optical fiber SPR detection system is designed and built up, which includes sample preparation systems, data acquisition, data analysis and other parts. Also the corresponding control software for process control, parameter setting, signal acquisition, algorithm analysis and other operations is wrote. This research realizes the combination of hardware and software. Based on this detection system, research mainly focused on algorithm, includes some items as follows.(1) The SPR signal filter algorithm.The signal is filtered by Savitzky-Golay filter, and parameter optimization of filters(fitting order and window width) is conducted in-depth research. It shows that SURE(Stein’s Unbiased Risk Estimate) is the MSE(Mean Square Error) unbiased estimator, SURE can estimate MSE accurately, and the purpose of parameter optimization can be achieved by making the SURE minimum.(2) The resonance wavelength calculation methods. After actual measurement, the SPR signal characteristics formed after multi-mode fiber conduction is learned, a wide span of sharp peaks can be gotten only, and this undoubtedly raises new requirements for signal processing. Fourier series fit method is proposed in this paper, which combines extreme value of one dimensional search method to solve optical resonance wavelength calculation. Verified by simulation, compared to centroid method,the resonant wavelength after fourier series fitting is accurate, stable, can truly reflect the actual resonant wavelengths, and is not sensitive to the fluctuations of the light, further more high concentration signals can be measured. By actual measurement of glycerol solution, concentration measurement can be realized through the calibration of concentration. Simultaneously, this paper provides partial software solutions for concrete implementation, thus it meet the needs of scientific research. This paper can also provide meaningful information and reference for optical fiber SPR analysis.