Design and analysis of surface plasmon resonance based photonic crystal fiber sensor employing gold nanowires

Abstract

A simple design of photonic crystal fiber (PCF) sensor which utilizes surface plasmon resonance (SPR) for refractive index detection is inspected to achieve high sensitivity. The offered sensor comprises of air holes in square lattice arrangement where two gold nanowires as a plasmonic material are located at the surface. Size-dependent plasmonic features of nanowires facilitates the coupling of SPR and fundamental core modes which leads to enhancement of sensor performance. With the propose of achieving the best result, the geometrical structure including the size of air holes and their arrangement in the PCF and also the size of nanowires are examined, in this work. Sensing performance of the proposed sensor is evaluated by finite element method using Comsol Multiphysics software. In y-polarization mode, the maximum wavelength and amplitude sensitivities of 50000 (nm/RIU) and 672.2 1/RIU have been obtained. The corresponding maximum values of figure of merit and resolution are 250 (1/RIU) and 2×10−6(RIU), respectively. This sensor includes remarkable prospect in chemical and biomedical detection because of its high sensitivity and low fabrication complexity. For example, the sensor performance is investigated for the cervical cancer cell detection and high sensitivity as 40000 (nm/RIU) is obtained.