为了在保证波长表面等离子体共振(SPR)分析仪动态范围的同时提高其分辨率,分析了波长SPR分析仪系统噪声对其探测能力的影响;以波长SPR分析仪的信噪比为目标,对波长SPR的数据处理进行优化。优化结果显示,最佳处理曲线为SPR信号最强时波长所对应的反射系数R,与信噪比最大时波长所对应的反射系数R:之间的前半部分SPR曲线。基于这段最佳处理曲线,采用了一种部分质心法数据处理方法。实验结果表明,采用此种算法可使SPR分析仪动态范围扩大一倍,在探测器光谱仪波长分辨率提高4倍的情况下,SPR分析仪的分辨率提高了将近10倍。采用此种算法测量折射率在1.3325~1.3600间的甘油溶液,线性相关系数〉0.99,说明此种算法对测试结果的线性度不会产生不利的影响,可满足波长SPR数据处理方法的要求。
To obtain a higher resolution and a widen dynamic range, the relationship between the system resolution and its noise of a spectroscopic Surface Plasmon Resonance(SPR) analyzer was ana- lyzed. For the purpose of improving the Signal to the Noise Ratio(SNR) of the analyzer,the data processing was optimized. The optimization result indicates that the optimized SPR curve should be between the Reflectance R1 corresponding to the strongest SPR signal and the Reflectance R2 corresponding to the largest SNR. And then, a partial centrolct metnod for data analysis was presented. The experimental results indicate that the dynamical range of measurement has been doubled by the proposed method. As the wavelength resolution of spectrometer has improved by 4 times, the resolution SPR analytical instrument can be increased by 10 times. Finally,the method was used to measure the solutions of Glycerin with refractive indexes between 1. 332 5 and 1. 360 0, and obtained correlation coefficients are larger than 0. 99, which means this method has not any unfavorable influence on the linearity result.