Compact Long-Period Fiber Gratings With Resonance at Second-Order Diffraction
Compact Long-Period Fiber Gratings With Resonance at Second-Order Diffraction
复制标题
具有二阶衍射共振的紧凑型长周期光纤光栅
DOI：
10.1109/lpt.2012.2204243
复制
发表时间：
2012-08-15
影响因子：
2.6
通讯作者：
Sun, Hong-Bo
中科院分区：
文献类型：
--
作者：
Guo, Jing-Chun;Yu, Yong-Sen;Sun, Hong-Bo
采用飞秒激光直写技术制备了长度为5 mm、长度为100 μ m的长周期光纤光栅。位于纤芯中心的几乎对称的光调制光栅段导致定义良好的透射光谱。LPFG可以将导模耦合到二阶衍射的高阶包层模，从而在1.433（类似于1.443）的折射率（RI）范围内产生5265 nm/RI单位的高RI灵敏度，并且在20 ° C至500 ° C的温度范围内产生-15.52 pm/° C的低温灵敏度。后一种性质是无串扰的高灵敏度RI传感器所期望的。
Compact 5-mm-long 100-mu m-period long-period fiber gratings (LPFGs) are fabricated by femtosecond laser direct writing. Nearly symmetrical photomodified grating segments located at the center of a fiber core lead to well-defined transmission spectra. The LPFGs can couple the guided mode to high-order cladding modes of second-order diffraction, resulting in a high refractive index (RI) sensitivity of 5265 nm/RI units in the RI range of 1.433 similar to 1.443 and a low-temperature sensitivity of -15.52 pm/degrees C from 20 degrees C to 500 degrees C. The latter property is desired for crosstalk-free high-sensitivity RI sensors.