基于噪声分析的波长表面等离子体共振分析仪的数据处理

波长SPR（表面等离子体共振）分析仪的分辨率主要取决于仪器的灵敏度和噪声水平决定的波长分辨率两部分，但高波长分辨率的光谱仪往往以牺牲波长探测范围为代价。因此，为了在保证波长SPR分析仪的动态范围的同时，提高其分辨率，降低波长SPR分析仪噪声的影响，分析了分析仪的噪声来源：与光强有关的光源本身产生的噪声和入射光光子噪声；与光强无关的信号后处理电路、温度等引起的噪声两部分噪声对SPR分析仪探测力的影响。以波长SPR分析仪的信噪比为目标，对波长SPR的数据处理进行了优化。其优化结果：最佳的处理曲线部分为SPR信号最强波长所对应的反射系数R1与信噪比最大波长所对应的反射系数R2之间前半部分的SPR曲线。基于这段最佳的处理曲线，提出了一种部分质心法的数据处理算法。实验结果表明，经优化后波长SPR分析仪，其分辨率提高了将近10倍，动态范围扩大了2倍，采用此种算法测得的折射率在1.3325-1.3600甘油溶液的线性相关系数大于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。

Data process of spectroscopic surface plasmon resonance analyzer based on noise analysis

The resolution of spectroscopy SPR (surface plasmon resonance) analytical instruments is mostly depended on the sensitivity of sensors and the wavelength resolution, which is relate to the instrument noise levels. But, as we know, the wavelength range of high-resolution spectroscopy is usually very narrow. In order to obtain higher resolving and widen the dynamic range, we analyses the noise sources and their type. These noises can be divided into two types based on the relation to the light source intensity. One is the noise in the intensity of light emitted by the light source and the shot noise, the other is the noise caused by temperature and supporting circuitry. SPR curve, which are involved in data analysis, has been optimized with the signal to noise ratio of spectroscopy SPR analytical instruments. The optimization result is that the optimization SPR cure should be between the Reflectance R1 corresponding to strongest SPR signal and the Reflectance R2 corresponding to strongest signal to noise ratio. And we put forward a part centroid method for data analysis. The experimental results indicate that the analytical instruments resolution has been improved by nearly ten times; the dynamical range of measurement has been enlarged two times. The Glycerin solutions, which are the Refractive index between 1.3325 and 1.3600, are tested. The correlation coefficients are larger than 0.99, that mean this method has not caused unfavorable influence on the result linearity.