Design and Analysis of Nano Gold Coated Refractive Index Sensor with Asymmetric Multiple Holes

This paper proposed a photonic crystal fiber based on the surface plasmon resonance, with rectangular and circular holes. Rectangular air holes reduce confinement losses, and small circular air holes provide better matching of core and plasmonic modes. Noble plasmonic material gold is used to excite the surface plasmon and increases the operating wavelength range (400–950 nm). The analyte is located outside the sensor, which makes it easy to build the sensor. Numerical results display that the suggested sensor displays maximum amplitude sensitivity of 1540 RIU−1, an amplitude resolution of 6.49 × 10−7 RIU, a maximum wavelength sensitivity of 9000 nm/RIU, and a wavelength resolution of 1.11 × 10−5 RIU using the amplitude and wavelength interrogation methods, respectively. In this sensor, because of the presence of gold, chemical stability in the environment is high. In addition, the suggested sensor is very promising for medical and pharmaceutical measurement and diagnostic applications due to its high sensitivity, easy diagnosis, and easy manufacturing.