Study On The Refractive Index Sensing Properties Of Graphene Coated Microstructural Fiber

With the development of optical fiber technology,fiber optics are used in the filed of sensors increasely because of its simple structure,small dimension and strong ability of resistance to electromagnetic interference.And with the advent of photonic crystal fiber,optical fiber sensing technology has made a qualitative leap;As a new material,graphene is widely used in photoelectric devices on account of unique zero band gap band structure,adjustable Fermi level characteristics,excellent optical electrical properties and high carrier mobility.This paper puts forwards the refractive index sensor and carries on the deep theory and the experiment research,then the characteristics of electro-optical modulation are analyzed theoretically,the main content is as follows:First of all,the thesis introduces the important role of optical fiber sensor technology briefly and summarizes the application of graphene in optical fiber communication and fiber sensing filed.Secondly,based on the unique band structure of graphene,the optical properties of graphene and electro-optic modulation characteristics are analyzed,and the preparation method of graphene as well as the simulation method is discussed in this paper.Thirdly,this paper uses COMSOL Multiphysics software based on finite element method to simulate the transmission characteristics of D-type single core photonic crystal fiber and study the influence of coating graphene layers and changing the depth of side polishing and the number of graphene layers to the properties of optical field.Then,the electro-optic modulation characteristics of the structure are simulated.The influence of chemical potential on the optical absorption properties of graphene was explored,and the influence of the electro-optic properties of graphene on the sensitivity of the sensor is obtained by changing the polishing depth and the number of graphene layers.Finally,according to the simulation results,the experiment is designed,and the preparation process of the sensor is described in detail.The refractive index sensing performance of the sensor is verified by experiments.The experimental results are analyzed and summarized,then presents the conclusion and analyzes the shortcomings.