Wide refractive index detection range sensors based on D-shape photonic crystal fiber with a nanoscale gold wire

Optical sensing based on photonic crystal fiber (PCF) is attracting interests. Currently, PCF sensing suffered from the insensitivity with the changes of environmental surroundings with low refractive index. A D-shape PCF supporting plasmonic resonances based on gold nanowires is designed to demonstrated the sensitivity optical sensing in the refractive index range from 1.00 to 1.30. The finite element method is performed to optimize the device parameters, including the diameter of the large and tiny air holes, the size of the gold nanowire, and the space between the air holes. Utilizing plasmon-induced confined electrical around gold nanowires, the predicted device performance in spectral and amplitude sensitivities are up to 19,400 nm/RIU and 5.15 × 10−6 RIU, respectively. It is believed that the designed sensor can promote the development of applications in biological and pharmaceutical.