Voisin Valérie, Caucheteur Christophe, Mégret Patrice, Albert Jacques
Electromagnetism and Telecommunication Department, Université de Mons, Mons, Belgium.
Appl Opt. 2011 Aug 1;50(22):4257-61. doi: 10.1364/AO.50.004257.
The generation of near-IR surface plasmon resonance in gold-coated tilted fiber Bragg gratings is strongly dependent on both the polarization state of the transmission light and the property of confining materials (including the coating materials and surrounding media). These dependencies can be advantageously used to demodulate the amplitude spectrum and retrieve the surrounding refractive index. In this paper, we present an automated demodulation technique that measures the surrounding refractive index by comparing the differential amplitude of resonance peaks near the plasmon attenuation for two orthogonal amplitude spectra recorded in the same operating conditions. A mean sensitivity of more than 500 nm per refractive index unit is reported. This new refractive index measurement method is shown to be accurate to 5×10(-5) over a full range of 0.01 in water solutions.
在涂金倾斜光纤布拉格光栅中产生近红外表面等离子体共振强烈依赖于传输光的偏振态和限制材料（包括涂层材料和周围介质）的特性。这些依赖性可有利地用于解调幅度谱并获取周围折射率。在本文中，我们提出了一种自动解调技术，该技术通过比较在相同操作条件下记录的两个正交幅度谱中靠近等离子体衰减处共振峰的差分幅度来测量周围折射率。报告的平均灵敏度超过每折射率单位500 nm。这种新的折射率测量方法在水溶液0.01的全范围内显示出精确到5×10(-5) 。
