Oil Transport Pipeline Leakage Monitoring Based On Tilted Fiber Bragg Grating

Fiber Bragg grating(FBG)is one of the optical passive components which develops rapidly in recent years,it has a lot of adventures,such as high sensitivity,realizes WDM easily,small and portable,low cost,etc.It has already been widely used in many fields,such as optical fiber sensing and optical communication,etc.Tilted fiber Bragg grating(TFBG)is a derivative of fiber Bragg grating device,it is a kind of short-period fiber grating which has a special structure,it not only possesses FBG's most advantages,but also has its own unique advantages,the greatest characteristic of tilted fiber Bragg grating is that it is very sensitive to the change of ambient refractive index.This feature is mainly due to its special structure of the grating profile,this article is mainly the detailed study of the tilted fiber Bragg grating and sensing properties,the main contents are as follows:Introduce the development of the fiber Bragg grating and tilted fiber Bragg grating,classification and applications in various fields,then simply introduce the development and the problems of oil pipeline,lay a foundation for the behind of a pipeline security monitoring system.Deduce the theory of TFBG's transmission properties gradually.firstly,we analyze the basic theory of light transmits in the fiber-optical,based on the helmholtz equation deducing coupled-mode theory;Secondly,we based on the coupled-mode theory analyzing the theory of the transmission of light in the fiber Bragg grating;finally,we based on the structure characteristics of fiber Bragg grating utilizing the transmission properties of the fiber Bragg grating to deduce the transmission theory of the tilted fiber Bragg grating.Utilize the OptiGrating software to simulate the transmission characteristics of tilted fiber Bragg grating which is popular in the international,to simulate and analyze the transmission spectrum's influence which depends on the change of the structural parameters(optical grating parameters and the optical fiber grating parameters)of tilted fiber Bragg grating.Then simulate and analyze the transmission spectrum's influence which depends on different sensing characteristics(stress,temperature and environment refractive index)of the tilted fiber Bragg grating.The result will provide a powerful reference for subsequent experiments.Do the experiment depending on the different sensing characteristics of the tilted fiber Bragg grating,then conclude the rule of the experiment.After that,we utilize the stress and temperature sensing characteristics of the tilted fiber Bragg grating to design a kind of early warning and monitoring system for oil pipeline safety;utilize refractive index sensing characteristics of tilted fiber Bragg grating to design a system for oil pipeline leaking monitoring.