Research On Photonic Crystal Fiber Grating Sensor

Photonic crystal fiber grating is developed on the basis of the fiber and fiber grating of new optical passive components,it also has the characteristics of photonic crystal fiber and the fiber grating,in the field of optical communication and optical fiber sensing play an extremely important role and continuous development.Fiber grating provides a good platform for the development of photonic crystal fiber.In this thesis,mainly in view of the photonic crystal fiber grating sensors are studied,has carried on the exploration from the following several aspects:First of all,the spectral characteristics of photonic crystal fiber grating are studied,based on the Coupled-Mode theory and combined with MATLAB simulation software,the influence of the variation of refractive index,duty cycle and modulation depth of photonic crystal fiber were done to better understand the reflectance spectra varying patterns along with the variation of these fiber grating parameters.The theoretical model of photonic crystal fiber grating for a long period can be obtained by theoretical analysis.Based on Coupled-Mode equation was derived for the resonant wavelength of long period photonic crystal fiber grating expression.According to the theory,a kind of bending long period of photonic crystal fiber grating sensor model is designed.Analyzed the working principle of the design of basic model,the numerical results show that the linear change relation approximately between curvature change and bending h in PCF LPG.The relationship between the effective refractive index of the fiber core,the effective refractive index of the cladding,the transverse strain,the longitudinal strain and the drift of the resonance wavelength and the strain of the grating,the period of the grating and the curvature of the fiber are obtained.