基于偏振分光棱镜的表面等离子体波传感系统

Prism Surface Plasmon Wave Sensor System Based on Polarizing Beam Splitter

常规棱镜表面等离子体共振（SPR）传感器检测系统共振波谷浅且谷底平坦,从而导致共振波长不易确定。在常规棱镜SPR传感器系统基础上,加入偏振分光棱镜（PBS）,构建了一种新型棱镜SPR传感器系统。对PBS的分光带宽展宽进行了研究,提出了基于膜系设计的展宽方法。在无水乙醇检测的实验中,滤除s偏振光后,共振波谷谷底曲率半径由86.2394减小到39.3990,近似减少为滤除s偏振光之前的1/2,这与理论分析相吻合。采用常规和新型棱镜SPR检测系统分别对折射率在1.32-1.39内的6种液体进行了测量,分辨率从1.62×10-4提高到1.55×10-4。该系统能较好地滤除s偏振光,使得共振波谷更加尖锐,从而提高共振光谱的检测精度。

In the traditional prism surface plasmon resonance（SPR） sensor system,the resonance trough is shallow and the valley is smooth,which causes the resonant wavelength difficult to determine.A novel detecting system is built which added a polarized beam splitter（PBS） based on traditional prism SPR sensor system.In the experiment of alcohol detection,when the S polarized light is filtered,the resonance radius of curvature decreases from 86.2394 to 39.3990,similar to the S polarized light presenced′s 50%,which coincides with the theoretical analysis.Traditional and novel prism SPR sensor system is used to measure 6 kinds of liquid whose refractive index is 1.32-1.39.The resolution ranges from 1.62×10-4 to 1.55×10-4.The detecting system with filter S polarized light that doesn′t excite SPR effect,which making a more acute resonance trough,thus detecting system has been improved.