A polished photonic crystal fiber sensor based on surface plasmon resonance for refractive index (RI) detection is proposed and analyzed by finite element analysis. The design of polishing can greatly increase the birefringence of photonic crystal fiber and ensure a uniform coating film, thus improving sensor performance. The outer air of the structure is arranged in half of an octagonal shape, and the inner layer is arranged in a quadrilateral shape, which can effectively improve coupling strength in the $ y $-polarization direction. The sensor works mainly in visible and infrared wavelengths with a detection range of 1.33 to 1.38. Through analysis of external RI changes, pore structure parameters, and silver mold thickness, the maximum sensitivity is 14800 nm/RIU, maximum amplitude sensitivity is ${766.7008}\;{{\rm RIU}^{- 1}}$, resolution is up to ${6.7568} \times {{10}^{- 6}}\;{\rm RIU}$, and maximum figure of merit is 548.1481. The sensor is suitable for biomedicine, environmental monitoring, chemistry, and other fields.

中文翻译：

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基于表面等离子体共振的抛光光子晶体光纤折射率传感器

提出了一种基于表面等离子体共振的用于折射率 (RI) 检测的抛光光子晶体光纤传感器，并通过有限元分析进行了分析。抛光的设计可以大大提高光子晶体光纤的双折射，保证镀膜均匀，从而提高传感器性能。该结构的外层空气呈半八角形排列，内层呈四边形排列，可有效提高$y$-极化方向的耦合强度。该传感器主要工作在可见光和红外波长，检测范围为1.33至1.38。通过分析外部RI变化、孔结构参数、银模厚度，最大灵敏度为14800 nm/RIU，最大振幅灵敏度为${766.7008}\;{{\rm RIU}^{- 1}}$，分辨率高达${6.7568} \times {{10}^{- 6}}\;{\rm RIU}$，和最大品质因数为 548.1481。该传感器适用于生物医学、环境监测、化学等领域。