单模光纤中布里渊动态光栅反射谱的特性  

Characteristics of Reflection Spectrum of Brillouin Dynamic Grating in Single Mode Fibers

作　　者：赖俊池 侯尚林[1] 雷景丽[1] 李晓晓[1] LAI Junchi;HOU Shanglin;LEI Jingli;LI Xiaoxiao(School of Science,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学理学院,兰州730050

出　　处：《光子学报》2021年第7期59-67,共9页Acta Photonica Sinica

基　　金：The National Natural Science Foundation of China(No.61665005);the Natural Science Foundation of Gansu Province of China(Nos.17JR5RA132,17JR5RA119);the HongLiu First-class Disciplines Development Program of Lanzhou University of Technology。

摘　　要：基于受激布里渊散射和弹性声学理论,给出了布里渊动态光栅理论模型。基于光纤布拉格光栅理论,采用数值模拟的方法计算了布里渊动态光栅的反射谱,证明了布里渊频移引起的布拉格波长下移等于多普勒频移。计算了泵浦功率为0.1~30 W、脉宽为2~10 ns、单模光纤芯径为8~10μm时的反射率和光谱宽度。当功率增长到30 W、脉宽达到10 ns时,峰值反射率分别达到2.17×10^(-6)和7.16×10^(-9);反射谱的光谱宽度随着脉冲宽度的增加而减小,当脉冲宽度为10 ns时,最小光谱宽度为1.2×10^(-4)nm;当纤芯直径减小到8μm时,反射率增长到6.64×10^(-11)。计算结果表明,布里渊动态光栅的反射率与泵浦波的功率和脉宽呈正相关,与光纤的纤芯直径呈负相关;反射谱的光谱宽度不受泵浦波功率和纤芯直径的影响,但与脉冲宽度呈负相关。The Brillouin dynamic grating model is developed based on the stimulated Brillouin scattering and elastic acoustic theory.The reflection spectrum of the Brillouin dynamic grating is calculated based on the fiber Bragg grating theory,and it is demonstrated that the Bragg wavelength downshifts by Brillouin frequency shift equals the Doppler frequency shift.The reflectivity and the spectral width are calculated when the pump power ranges from 0.1 W to 30 W,the pulse width ranges from 2 ns to 10 ns and the core diameter of a single mode fiber ranges from 8μm to 10μm.When the power increases to 30 W and the pump pulse width reaches 10 ns,the peak reflectivity is 2.17×10^(-6)and 7.16×10^(-9),respectively.The spectral width of the reflection spectrum decreases with the increase of pulse width.When the pulse width is 10 ns,the minimum spectral width is 1.2×10^(-4)nm.When the fiber core diameter decreases to 8μm,the peak reflectivity increases to 6.64×10^(-11).The results show that the reflectivity of the Brillouin dynamic grating is positive correlation with the power and the pulse width of the pump wave,but it is negative correlation with the core diameter of optical fiber.The spectral width of the reflection spectrum is not affected by the power of the pump wave and the diameter of the fiber core,but it is negative correlation with the pulse width.

关 键 词：受激布里渊散射 单模光纤 反射谱 光纤光栅 布里渊动态光栅 

分 类 号：TN929.11[电子电信—通信与信息系统]