从理论上推导了长周期光纤光栅在均匀温度场和非均匀温度场中透射谱的特性, 并实验验证长周期光纤光栅在均匀温度场中和非均匀温度场的光谱特性。实验证明, 随温度升高, 光纤光栅谐振波中心向长波方向漂移, 反之亦然, 且漂移量与温度的变化量呈线性关系。在非均匀温度场中, 当长周期光纤光栅的光栅两端温度差改变时, 谐振波的3dB展宽呈线性递增趋势。

The characteristics of long period fiber grating transmission in uniform temperature field and non-uniform temperature fields is theoretically analyzed. The spectrum characteristics of long period fiber grating transmission in uniform temperature field and non-uniform temperature field with experiments are demonstrated. Experiments prove that with the rise of temperature, the synchronous wave center of fiber grating drifts to the long wave direction, the reverse is also the true, and drift distance has linear relations with the variation of temperature. In non-uniform temperature filed, when the temperature difference on both grating ends of long period fiber grating changes, the 3dB spread of synchronous waves show the linear increasing trend.