A High Refractive Index Plasmonic Sensor Based on D-Shaped Photonic Crystal Fiber With Laterally Accessible Hollow-Core

A unique surface plasmon resonance (SPR) sensor based on photonic crystal fiber (PCF) is proposed in this paper, which consists of a D-shaped profile where a gold film is coated on its flat surface and a laterally accessible hollow core in which the analyte is infiltrated. The spectral sensitivity and the amplitude sensitivity of the proposed sensor are investigated by the finite element method when it is completely and partly immersed into the analyte solution. Simulation results indicate that the proposed sensor can detect the refractive index of the analyte higher than that of the PCF background, and shows higher sensitivity when its core portion is immersed into the analyte. In this way, this sensor can provide the ability of anti-interference from the metal coating. The proposed sensor can be conveniently coated with metal films and provides a possibility for real time sensing, which are not possible with traditional PCF-based SPR sensors.