【摘要】 古斯-汉欣位移是一种灵敏度极高的折射率测量办法,在温度、压力传感等方面有巨大的应用潜力,但测量精度要求较高。为解决测量的困难和提高古斯-汉兴测量精度,本文设计了一种棱镜-银纳米膜界面层,搭建了一套可测量多偏振态多角度古斯-汉兴位移的测量装置,以此测量了棱镜-空气和棱镜-银纳米膜不同界面的光束的古斯-汉欣位移,并对其物理机制进行了探讨。实验结果显示棱镜-空气界面的古斯-汉欣位移平均值是2.7μm,棱镜-银纳米膜界面的古斯-汉欣位移平均值是27.7μm,比棱镜-空气界面的位移增大了约10倍。使用COMSOL multiphysics软件模拟了棱镜-银纳米膜以及棱镜-空气界面的电场分布,对比棱镜-空气的情况,表明在消逝场作用下,银纳米颗粒表面形成了较强光场分布,光场方向沿入射光电场振动方向;银颗粒表面光场和消逝场的叠加使得消逝场增强,从而导致棱镜-银纳米膜界面的古斯-汉欣位移增大。本工作为提高基于古斯-汉欣位移效应的生物传感器的灵敏度提供了一个可供选择的手段。更多还原

【Abstract】 ■ highly sensitive refractive indexmeasurement method,which has great application potential in temperature and pressure sensing,but has high requirements for measurement accuracy.In order to solve the measurement difficulties and improve the measurement accuracy of ■nchen,Inthis paper,wedesigna prism-silver nanofilminterface layer and builda measuring device that can measure multi-polarization state and multi-angle ■nchenshift.The ■nchenshift of the beam at different interfaces of prism-air and prism-silver nanofilm was measured and its physical mechanism was discussed.The experimental results show that the average ■nchen shift at the prism-air and the silver nanofilm interfaces are 2.7 μm and 27.7 μm,respectively.The ■nchen shift at the silver nanofilm interface isenhancedmore than 10 times compared with that atthe prism-air interface.The electric field distribution at the prism-silver nanofilminterfaceandprism-airinterface was simulated using COMSOL multiphysics software.Theoretical analysis demonstratesthat the strong local field generated by the silver nanoparticles enhances the evanescent field,which contributes tothe improvementof the ■nchen shift at the prism-silver nanofilm interface.The research work provides analternativestrategyfor improving the sensitivityof thosebiosensorsbased on the ■nchenshift effect.更多还原