Opt Lett. 2018 May 15;43(10):2308-2311. doi: 10.1364/OL.43.002308.
Surface plasmon resonance excitation with optical fiber gratings has been typically studied in aqueous solutions. This work describes the procedure to excite a plasmon wave in gaseous media and perform refractive index measurements in these environments. Grating photo-inscription with 193 nm excimer laser radiation allows us to obtain slightly tilted fiber Bragg gratings exhibiting a cladding mode resonance comb along several hundreds of nanometers. Their refractive index sensitive range extends from gases to liquids, so operation in both media is compared. We demonstrate that the thickness of the metal coating required for surface plasmon excitation in gases is roughly one third of the one usually used for liquids. The developed platforms exhibit a temperature insensitive response of 78 nm/RIU when tested with different gases.
光纤光栅的表面等离子体激元激发通常在水溶液中进行研究。本工作描述了在气态介质中激发等离子体波并在这些环境中进行折射率测量的过程。使用 193nm 准分子激光辐射进行光栅光写入，使我们能够获得略微倾斜的光纤布拉格光栅，在几百纳米范围内表现出包层模共振梳。它们的折射率敏感范围从气体扩展到液体，因此比较了两种介质的工作情况。我们证明，在气体中激发表面等离子体所需的金属涂层的厚度大约是在液体中通常使用的厚度的三分之一。当用不同的气体进行测试时，所开发的平台表现出 78nm/RIU 的温度不敏感响应。
