侧边抛磨区材料折射率对光纤光栅波长的影响

针对轮式光纤侧边抛磨法,研究了在侧边抛磨光纤光栅抛磨区覆盖不同折射率的材料时,侧边抛磨光纤光栅Bragg波长随外界折射率的改变而变化的特性.理论计算与实验结果都表明,侧边抛磨光纤光栅Bragg波长会随抛磨区覆盖材料折射率的增大向长波长方向偏移；侧边抛磨面离光栅区纤芯表面越近,覆盖材料折射率对波长偏移的影响越大.实验指出,当侧边抛磨区覆盖材料的折射率从1.389 7变到1.447 9时,Bragg波长将会发生1.402 nm的偏移.用轮式光纤侧边抛磨法制备的侧边抛磨光纤光栅可应用于光纤光栅的波长调谐或传感器.

The Effect of Refractive Index of Material Overlaid Side Polished Area of FBG on Bragg Wavelength

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.