Analysis Of The Apodization Technique For Chirped Fiber Bragg Grating

Fiber grating is one of the typical fiber passive devices which is a recent research hotspot in the fields of sensor and communication. In the future, the applications of fiber grating will be emphasized with the developments of high-capacity communications and all-optical network technology. Apodization is a very important physical parameter for fiber grating to effect practical application. This article analyses the properties of apodization of fiber Bragg grating.To achieve the analysis, we start from the structure of fiber grating, and the couple-mode theory that is used in conjunction with transfer matix approach. Analysis of the apodization technique for linear and nonlinear chirped fiber Bragg grating is the main content of this article. In the section of apodized linear chirped fiber Bragg grating, this article compare the result of partly apodization with traditional single function. Then, we try to develop partly apodization into piecewise apodization, and describe the advantage of piecewise apodization technique. In the section of apodised nonlinear chirped fiber Bragg grating, we analyse the distortion of reflectivity, which results from nonlinear chirp and symmetrical apodization approach. So we try to adopt asymmetrical apodization to compensate this distortion. Finally, we present in this paper how to estimate the compensation capability.