Surface-plasmon-resonance-based fiber-optic refractive index sensor: sensitivity enhancement
Surface-plasmon-resonance-based fiber-optic refractive index sensor: sensitivity enhancement
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DOI：
10.1364/ao.50.002032
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发表时间：
2011-05-10
期刊：
影响因子：
1.9
通讯作者：
Gupta, Banshi D.
中科院分区：
文献类型：
--
作者：
Bhatia, Priya;Gupta, Banshi D.
采用波长解调的方法对基于表面等离子体共振(SPR)的高折射率介质层光纤折射率传感器进行了实验研究。银和金被用作SPR活性金属，然后是硅的高折射率介质层。实验结果表明，对于给定的硅层厚度，随着传感层折射率的增加，共振波长将发生红移。此外，随着硅层厚度的增加，传感器的灵敏度增加。提高灵敏度所需的硅膜厚度上限约为10 nm。在灵敏度方面的实验结果与用N层模型和射线方法得到的理论结果定性地吻合。灵敏度的提高是由于硅传感区界面处电场强度的增加。除了提高灵敏度外，硅层还可用于调谐共振波长，并可保护金属层免受氧化，从而提高探头的耐用性。(C)2011年美国光学学会
We have experimentally studied the surface plasmon resonance (SPR)-based fiber-optic refractive index sensor incorporating a high-index dielectric layer using the wavelength interrogation method. Silver and gold have been used as SPR active metals followed by a high-index dielectric layer of silicon. Experimental results predict a redshift in the resonance wavelength with the increase in the refractive index of the sensing layer for a given thickness of the silicon layer. Further, as the thickness of the silicon layer increases, the sensitivity of the sensor increases. The upper limit of the silicon film thickness for the enhancement of the sensitivity has been found to be around 10 nm. The experimental results obtained on sensitivity match qualitatively with the theoretical results obtained using the N-layer model and the ray approach. The increase in sensitivity is due to the increase in the electric field intensity at the silicon-sensing-region interface. In addition to an increase in sensitivity, the silicon layer can be used to tune the resonance wavelength and can protect the metal layer from oxidation and hence can improve the durability of the probe. (C) 2011 Optical Society of America