Theoretical Research On Spectral Characteristic Of Tilted Fiber Bragg Grating

Tilted Fiber Bragg Grating (TFBG) is a special kind of short-period Fiber Grating. Because of its unique structural characteristics, make its have all the advantages of fiber Bragg grating and long period fiber grating. In recent years, the theoretical and experimental study of TFBG has achieved certain results, and TFBG are widely used in optical communication、optical sensing and Light wavelength demodulation, etc.This paper first introduces the development of the fiber Bragg grating and types, from two aspects of communication and sensing applications of fiber Bragg grating is introduced. Then this paper expounds the production processes and Research actuality of the tilted fiber Bragg grating and their advantages and disadvantages are discussed. Transmission characteristics of TFBG are analyzed by coupled mode coupling theory. The mode coupling equations are deduced in detail under different coupling conditions.Then based on the software of OptiGrating impact of structure parameters of TFBG on the transmission and reflection spectra is studied by numerical simulation. Due to the existence of titled angel, the coupling property of grating has been radically changed. So the coupling capability of back propagating core mode might be weakened, the coupling capability of cladding mode will be enhanced. When reach a certain titled angle, the grating mode will be the specific type between the coupling of core forward mode and cladding forward mode.Finally we study the relationship between the resonance wavelength and the parameters such as temperature stress and refractive index. The temperature and strain responses of LP01 mode and LP05 mode are studied by computer simulation, and the linear fitting equation can also be respectively formulated. The results show that the different resonance wavelengths are linearity increased with ambient temperature and pressure and index.