A Plasmonic Sensor Based on D-shaped Dual-core Microchannel Photonic Crystal Fiber

In this paper, a dual-core microchannel-based fiber sensor is studied by using finite element method in the visible and near-infrared bands. Plasmonic material gold (Au) is deposited in microchannel to generate the surface plasmon resonance (SPR) effect, so that sensor can detect the change in RI of its surrounding analyte. Simulation results show that the maximum wavelength sensitivity and resolution are 33600 nm/RIU and 2.97 x 10(-6)RIU for y polarization in the RI range of 1.33 to 1.44, respectively. The highest figure of merit (FOM) of the sensor is 961 for y polarization. In addition, we study the effects brought by the structural changes of the fiber sensor, and the results show that the design of "microchannel coating" dramatically improves the refractive index (RI) detection ability of the sensor. The D-shaped dual-core microchannel-based photonic crystal fiber sensor proposed in this paper has a simple structure, low manufacturing complexity, and high sensitivity. Combined with external sensing technology, this sensor has great application potential in the fields of biotechnology, medical diagnosis, and environmental protection.