Study On The Sensing Characteristic Of Superstructure Fiber Bragg Gratings

Superstructure Fiber Bragg Grating is a novel fiber grating, and observers have devoted themselves to studying on related theories due to its special filtering characterizations, rigid wavelength space intervals, smart structure, easy-to-integrate and low cost.Based on coupled mode theory and transfer matrix method, the paper analyzes reflectance spectrum of Superstructure Fiber Bragg Grating and studies its strain and temperature sensing characterizations including the latter three aspects: related basic theories, spectral characterizations and sensing mechanism.Starting from basic theories of Superstructure Fiber Bragg Grating, the paper firstly analyzes Superstructure Fiber Bragg Grating with FFT transformations and coupled mode theories. With comparison, the paper employs coupled mode theory and transfer matrix method to resolve equations. Thus basic theories, spectral characterizations on Superstructure Fiber Bragg Grating are obtained which makes steps for simulation in the next chapter.Secondly, spectral characterizations on uniform, anodized Superstructure Fiber Bragg Grating are analyzed. Through adjusting involved parameters such as wavelength, refractive index average variation value, anodized function, ideal spectral characterizations are obtained. And suitable superstructure fiber grating fit for temperature and strain characterizations can be found.At last, based on above theories, the paper carries out temperature and strain simulated experiments on Superstructure Fiber Bragg Grating temperature and strain sensing characterizations. Then effects of temperature and strain on Superstructure Fiber Bragg Grating are analyzed, thus dependence of Superstructure Fiber Bragg Grating reflectivity and wavelength on temperature and strain is determined. At the same time, the paper analyzes experimental system and error, which makes theoretical basis for practicalapplication in sensing fields of Superstructure Fiber Bragg Grating.