The Effect of Refractive Index of Material Overlaid Side Polished Area of FBG on Bragg Wavelength
侧边抛磨区材料折射率对光纤光栅波长的影响

When one side of cladding layer of a FBG was reduced to several micrometers by polishing,a FBG become a side polished FBG.Based on the polishing method with a motor-driven polishing wheel, it was studyed that response of Bragg wave-length of side-polished FBG to the refractive indexes of materials overlaid the polished area of a side polished FBG by both theoretical simulation and experiments.Both simulation and experiments showed that the Bragg wavelength of side polished FBG shifted to the longer wavelength direction as the refractive index of the overlaying material increased.The experimentd showed that the more closer to the core layer of fiber the polished surface was the more bigger the shift of the Bragg wavelength was.As the index of the overlaying material changed from 1.389 7 to 1.447 9,the shift of Bragg wavelength got to 1.402 nm.The side polished FBG with good sensitivity to outer overlaying material could be used for process of FBG wavelength tuning or as an refractive index sensors.