Tabassum Rana, Gupta Banshi D
Appl Opt. 2015 Feb 10;54(5):1032-40. doi: 10.1364/AO.54.001032.
We analyze surface plasmon resonance-based fiber-optic sensor for sensing of small concentrations of hydrogen gas in the visible region of the electromagnetic spectrum. One of the two probes considered has multilayers of zinc oxide (ZnO) and palladium (Pd) while the other has layer of their composite over a silver coated unclad core of the fiber. The analysis is carried out for different volume fractions of palladium nanoparticles dispersed in zinc oxide host material in the nanocomposite layer. For the analysis, a Maxwell-Garnett model is adopted for calculating the dielectric function of a ZnO:Pd nanocomposite having nanoparticles of dimensions smaller than the wavelength of radiation used. The effects of the volume fraction of the nanoparticles in the nanocomposite and the thickness of the nanocomposite layer on the figure of merit of the sensor have been studied. The film thickness of the layer and the volume fraction of nanoparticles in the ZnO:Pd nanocomposite layer have been optimized to achieve the maximum value of the figure of merit of the sensor. It has been found that the figure of merit of the sensing probe coated with ZnO:Pd nanocomposite is more than twofold of the sensing probe coated with multilayers of Pd and ZnO over a silver coated unclad core of the fiber; hence, the sensor with a nanocomposite layer works better than that with multilayers of zinc oxide and palladium. The sensor can be used for online monitoring and remote sensing of hydrogen gas.
我们分析了基于表面等离子体共振的光纤传感器，用于在电磁光谱的可见光区域检测低浓度氢气。所考虑的两个探头之一具有氧化锌（ZnO）和钯（Pd）的多层结构，而另一个在光纤的镀银裸芯上有它们的复合层。对纳米复合层中分散在氧化锌主体材料中的不同体积分数的钯纳米颗粒进行了分析。为了进行分析，采用麦克斯韦 - 加尼特模型来计算具有尺寸小于所用辐射波长的纳米颗粒的ZnO:Pd纳米复合材料的介电函数。研究了纳米复合材料中纳米颗粒的体积分数和纳米复合层的厚度对传感器品质因数的影响。优化了层的膜厚和ZnO:Pd纳米复合层中纳米颗粒的体积分数，以实现传感器品质因数的最大值。已发现，在光纤的镀银裸芯上涂覆ZnO:Pd纳米复合材料的传感探头的品质因数是涂覆Pd和ZnO多层结构的传感探头的两倍多；因此，具有纳米复合层的传感器比具有氧化锌和钯多层结构的传感器性能更好。该传感器可用于氢气的在线监测和遥感。
