Influence On The Transmission Characteristic Of Optical Fiber And Fiber Gratings With Novel Cladding

In the word, we introduce a novel optical fiber and fiber Bragg gratings with uniaxial crystal materials which the optical axis is parallel to the principal axis (z axis) of optical fiber. Through simulated calculation, we analyze the influence of Bragg wavelength and maximum reflectivity along with the electro-optic effect and elasto-optic effect of uniaxial crystal materials, it provides us the foundation for designing the novel all-optical devices on the basis of fiber Bragg gratings.(1)For the electro-optic effect, the ordinary refraction extraordinary refraction,the ratio of the extraordinary ray refractive index to the ordinary ray index Ncl will decrease along with the increase of electric intensity, but the normalized core-cladding index difference△cl will increase;△cl is the main factors of the decrease of the Bragg wavelengthλB,△cl and Ncl will reduce it; Along with the increase of electric intensity, the Bragg wavelengthλB will decrease, and the maximum refractivity will increase;Along with the increase of the tuned range of the electric intensity, the structural parameter will change, and the tuned range of Bragg wavelengthλB will increase.(2)For the elasto-optic effect, along with the increase of strain, the ordinary refraction and extraordinary refraction will decrease, the ratio of the extraordinary ray refractive index to the ordinary ray index Ncl and the normalized core-cladding index difference△cl will increase, the Bragg wavelengthλB will decrease, and the maximum refractivity will increase;△cl is the main factors of the variation of the Bragg wavelength AB, it will decrease with the variation of Ncl and△cl. In addition, the maximum refractivity will increase along with the increase of the length of fiber gratings and number of grid cells.