Extremely narrow resonances, giant sensitivity and field enhancement in low-loss waveguide sensors
Extremely narrow resonances, giant sensitivity and field enhancement in low-loss waveguide sensors
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DOI：
10.1088/2040-8978/18/6/065004
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发表时间：
2016-06-01
影响因子：
2.1
通讯作者：
Sekkat, Z.
中科院分区：
文献类型：
--
作者：
Nesterenko, D. V.;Hayashi, S.;Sekkat, Z.
支持波导模式激励的低损耗波导(WG)是基于由低折射率介质隔离层从吸收膜中分离出来的介质WG。我们对Kretschmann位形平面传感结构中WG的损耗对激励的共振特性的影响进行了数值和分析研究。我们证明了对于S偏振和p偏振，WMS的损耗程度都可以由隔离层的厚度来控制。由于低损耗WMS的激发，在反射率光谱中发现了极窄的共振，并且估计的强度灵敏度的最大值比传统的表面等离子体传感器和WG耦合表面等离子体传感器高10(5)倍。我们发现，在水敏介质中，传感结构表面的巨场强增强了10(7)倍，可以在较低的样品体积下为荧光标记传感提供更强的荧光强度。
Low-loss waveguides (WGs), which support excitation of waveguide modes (WMs), are based on a dielectric WG separated from an absorptive film by a low-index dielectric spacer layer. We perform numerical and analytical study of the impact of the losses imposed to the WG in a planar sensing structure in the Kretschmann configuration on the resonance properties of the excitation. We demonstrate that the loss degree of the WMs can be controlled by the thickness of the spacer layer for both s and p polarizations. Extremely narrow resonances are discovered in the reflectivity spectra due to excitation of the low-loss WMs, and the maximum of the estimated sensitivity by intensity is found to be of 10(5)-fold higher as compared to the conventional surface plasmon and WG-coupled surface plasmon sensors. We reveal the giant field intensity enhancement of 10(7)-fold on the surface of the sensing structure in aqueous sensing media that can provide stronger fluorescence intensity at lower sample volumes for fluorescent labeling sensing.