电极放电对光纤光栅光谱特性的影响

Influence of Electrode Discharge on Fiber Bragg Grating Spectral Characteristics

采用电极脉冲电弧放电激励紫外曝光刻写的光纤布拉格光栅(FBG),重点研究了电极在栅区不同位置放电对光纤光栅光谱特性的影响。实验发现,在电极放电激励时,光栅反射率下降,光谱展宽并红移,放电引起的光谱变化具有可逆性。采用传输矩阵方法,在理论上分析了光纤光栅在电极放电产生的非均匀温度场下的光谱特性,与实验结果吻合。特别地,当电极在栅区中心位置放电时,光栅反射率下降幅度达到最大,反射谱峰值比无电极放电时小12dB,表现出开关量特性。

The electrode pulsed arc discharge excitation experiments on fiber Bragg grating （FBG） inscribed by ultraviolet exposure are reported. The effect of discharging at different grating positions on the spectral characteristics of fiber grating is studied especially. Experimental results show that the reflectivity of fiber grating is decreased,the grating spectrum is broadened and shows a red shift during electrode discharge excitation. The spectral changes induced by discharge are reversible. The spectral characteristics of fiber grating are analyzed in a non-uniform temperature field formed by electrode discharge with the transfer matrix method, and the theoretical results are in good agreement with the experimental results. Specifically, when the electrode discharges in the center of fiber grating, the decline amplitude of grating reflectivity reaches to maximum and the optical reflection spectrum is 12 dB less than initial spectrum, which shows switching characteristic.