A Novel Photonic Crystal Fiber Biosensor Using Surface Plasmon Resonance

Abstract

A novel photonic crystal fiber (PCF) biosensor based on surface plasmon resonance (SPR) phenomena is proposed. Chemically stable active plasmonic material gold (Au) and sensing layer is used outside the fiber structure to make the sensor configuration simpler. The proposed sensor would be able to detect the unknown analytes by flowing through the metal surface or dripped on the outer surface of the metal layer. The proposed sensor is consist with the symmetrical circular air-holes. Two small air-holes are used in the second rings which helps to produce the more evanescent field as well as helps to tune the phase matching between the core guided mode and surface plasmon polaritons (SPP) mode. Surface plasmons along the metal surface is excited with the leaky Gaussian-like core guided mode. Guiding properties and the sensing performance are numerically investigated by the Finite Element Method (FEM). A circular, perfectly matched layer is used to absorb the radiation towards the surface. Using the wavelength interrogation mode, proposed sensor shows the maximum sensitivity of 1,000 nm/RIU (Refractive Index Unit), with the sensor resolution as low as 1×10^-4 RIU. The proposed sensor design shows the promising results that could be used in biological and biochemical analytes detection.