基于光谱解调的对称波导型表面等离子体共振传感研究

表面等离子体共振(SPR)传感系统有角度谱、光谱、强度、相位等解调方式，其中光谱型的(SPR)传感系统因可以使用光纤导光，将传感部分独立出来，可进行远距离传感和现场检测，并能有效缩小系统的体积。对称光波导型(SOW)SPR因金属膜层两边的折射率完全相同，表面等离子体波传播距离更长，穿透深度更深，比传统的SPR系统具有更高的灵敏度和分辨率。对对称波导型(SOW)SPR进行光谱解调研究，以MgF₂-Au-MgF₂结构的SOW-SPR为传感单元，同时以光纤输出的卤素灯为光源, 搭建了一套光谱解调的SOW-SPR检测系统，以不同浓度的葡萄糖溶液对系统折射率分辨率进行测量，得到2.8×10-7 RIU的分辨率。为SOW-SPR系统小型化、现场检测以及远距离探测提出一种可能实现的手段，具有很好的应用前景。

Research on Symmetrical Optical Waveguide Based Surface Plasmon Resonance Sensing with Spectral Interrogation

Surface plasmon resonance (SPR) sensors with spectral interrogation can adopt fiber to transmit light signals, thus leaving the sensing part separated, which is very convenient for miniaturization, remote-sensing and on-site analysis. Symmetrical optical waveguide (SOW) SPR has the same refractive index of the two buffer media layers adjacent to the metal film, resulting in longer propagation distance, deeper penetration depth and better performance compared to conventional SPR. In the present paper, we developed a symmetrical optical waveguide (SOW) SPR sensor with wavelength interrogation. In the system, MgF₂-Au-MgF₂ film was used as SOW module for glucose sensing, and a fiber based light source and detection was used in the spectral interrogation. In the experiment, a refractive index resolution of 2.8×10-7 RIU in fluid protocol was acquired. This technique provides advantages of high resolution and could have potential use in compact design, on-site analysis and remote sensing.