Ultra-High Sensitivity Dual-Polarized D-Type Photonic Crystal Fiber Sensor Coated with MoO₂ film

Optical fiber sensing has a wide range of applications in various fields. It requires strong sensitivity and synergistic effects of sensors. Two-dimensional materials have been extensively explored, due to their excellent properties and great applications in electronics, optoelectronics, spintronics, and other fields. In this paper, we combined optical fiber sensing with two-dimensional materials and have presented an ultra-high sensitivity two-polarized D-type photonic crystal fiber (PCF) sensor on the basis of molybdenum dioxide (MoO₂) nanofilm. Numerical simulations show that the sensor is able to detect the refractive index (RI) of the analyzer from 1.393 to 1.416. The average wavelength sensitivity of the sensor is 21,668.81 nm/RIU in the x-polarized direction and 23,401.80 nm/RIU in the y-polarized direction. It has been shown that MoO₂ has the great potential for optical fiber sensing as a plasmonic sensing material.