De Moutusi, Singh Vinod Kumar
Appl Opt. 2020 Jan 10;59(2):380-388. doi: 10.1364/AO.59.000380.
In this paper, we propose an efficient double-layered flat fiber (DLFF) plasmonic refractive index sensor having high resolution and linearity. Thin gold film is used as surface plasmon resonance (SPR) active material protected by a titanium dioxide layer, both deposited on the upper flat surface of DLFF. The sensor consists of an analyte channel in the central core hole as well as on the top of the fiber. Structural parameters of DLFF and thickness of gold and titanium dioxide layer are analyzed based on the finite element method. The optimized structure is studied based on wavelength and amplitude interrogation techniques in the near-infrared region. Numerical results show average wavelength sensitivity of 12172 nm/RIU with a resolution of 8.21×10 (refractive index unit) in the highly refractive index (RI) range from 1.445 to 1.490. Further, amplitude sensitivity of this probe is found to be 2910 with a resolution of 3.44×10, which is the highest among all reported PCF SPR sensors, as per the authors' best knowledge. Compared with traditional photonic crystal fiber, the designed DLFF makes the sensor configuration simple to fabricate as well as a potential candidate for developing biochemical sensors and portable devices.
在本文中，我们提出了一种高效的双层扁平光纤（DLFF）表面等离子体共振折射率传感器，具有高分辨率和线性度。薄金膜用作表面等离子体共振（SPR）活性材料，由二氧化钛层保护，两者都沉积在DLFF的上平面表面上。该传感器由位于中心芯孔以及光纤顶部的分析物通道组成。基于有限元方法分析了DLFF的结构参数以及金和二氧化钛层的厚度。基于近红外区域的波长和幅度询问技术研究了优化结构。数值结果表明，在1.445至1.490的高折射率（RI）范围内，平均波长灵敏度为12172 nm/RIU，分辨率为8.21×10（折射率单位）。此外，据作者所知，该探头的幅度灵敏度为2910，分辨率为3.44×10，这是所有报道的光子晶体光纤SPR传感器中最高的。与传统光子晶体光纤相比，所设计的DLFF使传感器配置易于制造，并且是开发生化传感器和便携式设备的潜在候选者。
