数值求解了光子晶体光纤中的去极化型声波导布里渊散射色散方程, 研究了光子晶体光纤中的布里渊频移随泵浦波长及空气孔填充率的变化关系, 以及去极化型声波导布里渊散射频移随温度、应变、声波导模式、纤芯直径及空气孔层数的关系。结果表明: 布里渊频移随着波长的增大而线性减小。对于相同的波长点, 增大光子晶体光纤空气孔填充率时, 声波横向速度将会减小。去极化型声波导布里渊散射频移随温度及应变的增大而线性增加。同一温度条件下, 高阶TR2m模式的去极化型声波导布里渊散射频移对温度的变化更为敏感; 而在同一应变条件下, 低阶TR2m模式的去极化型声波导布里渊散射频移对应变的变化更为敏感。去极化型声波导布里渊散射频移随纤芯直径的增加而增大, 随空气孔层数的增加而减小。

The dispersion equation of depolarized-guided acoustic wave Brillouin scattering (De-GAWBS) in photonic crystal fiber was numerically solved. The relationship of Brillouin frequency shift with pump wavelength and air hole filling fraction was studied. The dependency of De-GAWBS frequency shift on temperature, tensile strain, acoustic modes, the core diameter of photonic crystal fiber, and the number of air hole layers was investigated. The Brillouin frequency shift decreases linearly with the wavelength increasing, and the transverse velocity of acoustic wave decreases with the increasing of the air hole filling fraction at the same wavelength. The De-GAWBS frequency shift increases linearly with the increasing of temperature and strain. The frequency shift of the higher order torsional-radial mode is more sensitive in the same temperature condition, and the frequency shift of the lower order torsional-radial mode is more sensitive in the same tensile strain condition. The resonance frequency shift increases with the core diameter increasing and decreases with the number of layers of air hole increasing.