薄包层长周期光纤光栅的折射率传感特性  

Sensitivity of the Thin-Clading Long Period Fiber Gratings to Refractive Index

作　　者：张自嘉[1] 许安涛[2] 

机构地区：[1]南京信息工程大学信息与控制学院,南京210044 [2]焦作师范高等专科学校,河南焦作454000

出　　处：《传感技术学报》2009年第8期1105-1108,共4页Chinese Journal of Sensors and Actuators

摘　　要：长周期光纤光栅(LPFG)可用于折射率传感,同时利用折射变化可以实现谐振波长的调谐。不同的光纤包层半径和光栅周期对折射率灵敏度有较大影响,利用光波导的耦合模理论分析了LPFG的折射率传感特性,给出LPFG的折射率灵敏度的解析表达式,给出了利用不同包层模时的折射率灵敏度。利用三层介质光纤的纤芯模本征方程计算了薄包层LPFG的折射率灵敏度。结果表明,基于不同包层模的LPFG的谐振波长随折射率的变化有红移,也有兰移;基于低阶模序包层模的LPFG,折射率灵敏度较小,中间模序最大,而高阶模序则较大,薄包层LPFG对折射率具有更大的灵敏度。Long period fiber gratings（LPFGs） can be used as sensor of refractive index, which the sensitivity is related to the radius of the fiber clading and the period of the fiber gratings. The sensitivity to the refractive index is analyzed by using the coupled-mode theory and the formula is derived. The sensitivities of LPFGs using different calding modes and thin-clading LPFGs to-refractive index is calculated, which shows that the resonance wavelength of LPFGs using differtent cladding modes may have red or blue shifts with the change of the refractive index; and the sensitivity of LPFGs of clading mode on using low order is smaller than that on clading modes using higher order,but that clading modes on using middle order is the biggest. The sensitivity of thin-clading LPFGs is geater than that the usual LPFGs.

关 键 词：长周期光纤光栅 折射率传感器 薄包层 

分 类 号：TN253[电子电信—物理电子学]