Analysis of a Hexagonal Lattice Photonic Crystal Fiber Biosensor Based on Surface Plasmon Resonance

A simple gold-coated hexagonal lattice photonic crystal fiber (PCF) biosensor is proposed in this article. COMSOL Multiphysics software is used for numerical performance study of the recommended sensor with the Finite Element Method (FEM). Gold as plasmonic layer that is chemically stable can be set externally on the fiber structure through the chemical vapor deposition method (CVD). Numerically it is found that the proposed biosensor can identify analyte refractive index (RI) in the range 1.33-1.41. To increase sensitivity and produce birefringence, air holes are removed in the first ring of the PCF biosensor. The proposed biosensor displays the maximum wavelength sensitivities of 11500 nm/RIU and 11000 nm/RIU for x-polarization and y-polarization modes, respectively. The sensitivity is also measured by amplitude sensitivity analysis. The maximum amplitude sensitivities are 1755.81 RIU
^-1
and 1792.40 RIU
^-1
for x-polarization and y-polarization, respectively. Moreover, sensor resolutions are $1.14\times 10^{-5}$ RIU and $9.70\times 10^{-6}$ RIU for x-polarization and y-polarization, respectively.