飞秒激光刻写FBG在电极放电下的光谱特性

Spectral characteristics of FBG inscribed by femtosecond laser under electrode discharge

采用电极脉冲电弧放电对紫外激光和飞秒激光刻写的光纤布拉格光栅(FBG)进行高温激励的研究,实验发现,紫外激光刻写的FBG,光栅透射谱大幅下降,光谱蓝移0.38 nm,飞秒激光刻写的FBG透射谱基本保持不变,光谱红移0.022 nm。特别是当电极在栅区中心位置放电时,光栅透射率上升达到最大,比无电极放电时大8 d B,表现出开关量特性。该特性在光纤开关量器件、光纤调Q激光器、新型光纤光栅解调与局部放电检测等领域具有潜在的应用前景。

The electrode pulsed arc discharge excitation experiments on fiber Bragg grating （FBG） inscribed by UV and femtosecond laser are reported. Experimental results show that the transmission spectrum intensity of UV-FBG is decreased and blue shift of the spectra is about 0.38 nm; the transmission spectrum intensity of femtosecond laser- FBG is almost constant and red shift of the spectra is about 0.022 nm. Specifically, when the electrode discharges in the center of fiber grating, the grating transmissivity reaches maximum and the transmission spectrum intensity is 8 dB more than initial spectrum, which shows switching characteristic. This characteristic may have a potential application prospect in the optical switch component, a novel fiber grating demodulation and partial discharge detection field.