Plasmonic Dual D-shaped PCF Sensor for Low Refractive Index Applications

Dual D-shaped (DD-shaped) plasmonic photonic crystal fiber (PCF) for refractive index sensing is designed and analyzed. In the proposed design, two gold nano-rods are attached to the two etched surfaces of the PCF to enhance the sensing characteristics. The surface plasmon (SP) modes excited at the metal/dielectric interfaces are strongly coupled to the PCF core mode. Therefore, high refractive index (RI) sensitivity of 19100 nm/RIU is achieved. Such a sensor can be employed in environmental monitoring and food safety applications.