Analysis Of Acousto-Optic Modulator Based On Fiber Bragg Grating By Ⅴ-Ⅰ Transmission Matrix Formalism

The acousto-optic modulator based on the Fiber Bragg Grating with wide tuning range, the fast response speed and low insertion loss, is widely used in the field of the optical fiber communication and the optical fiber sensors. Fast and efficient access to spectra performances of the Fiber Bragg Grating has a significant role in the optimizing the design of the fiber grating with complex structures.In this thesis, the V-I transmission matrix formalism widely used in the field of engineering is applied to the theoretical analysis of the acousto-optic modulator based on the Fiber Bragg Grating, and the model is applied to analyze the non-uniform FBG AOM, the main research contents of this thesis are listed as follows:1. At the point of the theoretical analysis,We put forward the four kinds of the common methods for analysis the fiber grating, such as the coupled mode method,transfer matrix method, the Fourier transform and he multilayer method and the V-I transmission matrix method to analyze the spectrum performance of the Fiber Bragg Grating is built on these models. The V-I transmission matrix formalism is more simple in algorithm and more easily to obtain the transmission characteristics quickly comparing with the existing various analysis methods.2. The V-I transmission matrix formalism was applied to analyze the influence of the acoustic frequency and the induced strain to the acousto-optic modulator based on the uniform Fiber Bragg Grating, the ratio of the wavelength spacing between the primary reflection peak and the first-order secondary reflection peak and the acoustic frequency is about0.145nm/MHz. Compared with other methods, highlight the V-I transmission matrix formalism is more fast and effective.3. For the acousto-optic modulator based on the chirped Fiber Bragg Grating and phase-shifted Fiber Bragg Grating, the V-I transmission matrix formalism is used to analyze the influence of spectrum caused by acoustic frequency and induced strain and we get the relationship between the wavelength spacing between the primary reflection peak and the first-order secondary reflection peak and the acoustic frequency, as well as the reflectivity of reflection peak and the change rule of amplitude with induced strain. And put forward the longitudinal acoustic wave generated by shear modulus PZT, we use the acoustic frequency with2MHz to modulate chirped Fiber Bragg Grating, the results of experimental and simulation are consistent.