倾斜光纤光栅折射率传感特性研究

Research on the Sensing Characteristics of Tilted Fiber Bragg Grating Refractive Index

根据倾斜光纤光栅的折射率传感原理,通过仿真研究不同包层模式在不同包层直径条件下有效折射率和包层模谐振波长的变化规律。结果表明:随环境折射率的增大,各阶包层模式的有效折射率变大,高阶包层模具有更好的折射率灵敏度。包层直径越小,引起的有效折射率偏移量越大。最后给出了环境折射率1. 35～1. 40范围内的波长拟合关系。

Based on refractive index sensing principle of tilted fiber bragg grating （TFBG） , a simulation study on the change law of effective refractive index and resonant wavelength of cladding modes with different cladding diameters was implemented. The results show that, effective refractive of the cladding modes is increased with increasing of surrounding refractive index （RI） , and the high order cladding mode has higher sensitivity in contrast to the low order ones; the smaller cladding diameter brings about larger effective RI shift. Finally, the fitting curves of wavelength were presented when the surrounding refractive index varies from 1.35 to 1.40.