D-Shaped Photonic Crystal Fiber Based Surface Plasmon Resonance Sensor Using Dual Coating of Metal Oxide for Healthcare Applications

The phenomenon of surface plasmon resonance (SPR) is the basis of adsorption measurements for many tools that have resulted in several sensor applications. In this paper, a D-shaped photonic crystal fiber (PCF) based surface plasmon resonance (SPR) sensor with dual coating of conducting metal oxide is proposed. A brief study is performed to analyze the use of dual coated metal oxide plasmonic material to sense the lower refractive index (RI) chemicals. Firstly, the flat surface of photonic crystal fiber is coated with Indium Tin Oxide (ITO) followed by a coat of Zinc Oxide (ZnO) to enhance the plasmonpolariton generation. The SPR wavelength is tuned to the infrared region by changing the metal doping concentration. The external flat surface of the sensor is more convenient for liquid infiltration than liquid filling into small circular holes in conventional PCF sensors. The proposed sensor design has maximum wavelength sensitivity of 10000 nm/RIU in the RI detection range of 1.30-1.38 with a resolution of $2.0 \times 10^{-5}$ and can be utilized specifically in the lab-on-chip technology for healthcare industry.