Study Of Fiber Optic Sensor And Sensing Mechanism Based On Transition Metal Oxide ENZ Mode

Epsilon-Near-Zero(ENZ)materials are materials with near-zero dielectric constants at specific wavelengths.In the last decade,such materials have attracted much attention because of their slow light effect,enhanced electric field,and perfect absorption.These exotic properties make ENZ modes a new pathway for manipulating light-matter interactions at the nanoscale.Due to the lack of theoretical studies on the sensing mechanism of ENZ materials,applied research on the application of ENZ effect to optical fiber sensing is relatively few and not deep enough.Therefore,this study will investigate and discuss the sensing mechanism of ENZ mode from the perspective of perfect absorption.The research contents and results of this paper are as follows:1.An introduction to the optical transmission and swift field and its excited ENZ mode in the Dtype fiber equivalent model.The optical transmission and swift wave equations in optical fiber and the penetration depth of swift wave are introduced;the principle of Surface Plasma Resonance(SPR)is introduced,and the interrelationship between SPR mode and ENZ mode is explained by the dispersion curve,followed by the perfect absorption conditions of ENZ mode;finally,the article The numerical analysis method of COMSOL Multiphysics,the finite element simulation software used,is introduced.2.In:CdO is plated on D-type optical fiber to investigate the performance and mechanism of its ENZ mode in sensing.The simulation was performed using COMSOL Multiphysics finite element simulation software,and the In:CdO film was plated on the middle of the D-type fiber side profile,and the mode analysis was performed on the overall model to calculate and analyze the loss peak height variation and wavelength shift corresponding to different external medium refractive indices under different fiber platforms,different film thicknesses and different mobility conditions,by combining the electric field By combining the electric field continuity condition with the perfect absorption condition,the sensing mechanism is explained.3.A D-type photonic crystal fiber sensor based on the ENZ mode of In:CdO with high sensitivity and narrow half-peak width in the C-band of communication is designed.A D-type photonic crystal fiber was designed,whose cladding consists of small circular vents arranged in a positive hexagonal shape in the inner layer and large circular vents arranged in a positive triangle in the outer layer as well as elliptical vents of two sizes,and the ENZ material was plated on the inner side of the large circular vents after side dissection as the sensing channel;the effects of different large hole radii,small hole spacing and film thickness and mobility on the sensitivity and full half-peak width were discussed,and it was found that the large hole radii It is found that the large hole radius and the thickness and mobility of the film have a great influence on the sensing performance,and the sensitivity of 2333 nm/RIU and the narrowest half-peak full width of 60 nm can be achieved in the communication C-band,which has the potential to replace the traditional SPR effect in the communication C-band.