Ultra-high sensitivity D-type photonic crystal fiber sensor deposited with MoO2 nanofilm

Fiber optic sensing technology has extensive applications in many fields and demands high sensitivity and cost-effectiveness for sensors. In this study, we propose an ultra-high sensitivity D-type photonic crystal fiber sensor based on MoO2 nano-film coating to meet this requirement. Firstly, MoO2 is selected as the plasmonic excitation material. Compared to expensive metals such as Au and Ag, MoO2 has the characteristics of low cost and charge carrier density, which is suitable for use in optical fiber sensing modules. The sensitivity of the sensor to the external environment can be increased by coating the surface of the optical fiber with MoO2 nano-film. Then, we use the finite element method to evaluate the performance of the sensor. Numerical simulation results show that the average wavelength sensitivity of the sensor in the x-polarization direction is as high as 24000 nm/RIU when analyzing substances with refractive indices ranging from 1.38 to 1.43. This means that the sensor has a very sensitive response to refractive index changes and can be widely applied to sensing needs in different fields. Overall, the D-type photonic crystal fiber sensor based on MoO2 nanofilm coating has enormous potential for applications. This sensor can achieve high-sensitivity detection within a specified range of refractive indices, providing new ideas and methods for research and applications in the field of fiber sensing.