All-Optical Control of Gigahertz Acoustic Resonances by Forward Stimulated Interpolarization Scattering in a Photonic Crystal Fiber
All-Optical Control of Gigahertz Acoustic Resonances by Forward Stimulated Interpolarization Scattering in a Photonic Crystal Fiber
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DOI：
10.1103/physrevlett.105.153901
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发表时间：
2010-10-05
影响因子：
8.6
通讯作者：
Russell, P. St. J.
中科院分区：
文献类型：
--
作者：
Kang, M. S.;Brenn, A.;Russell, P. St. J.
我们报告了一种新的非线性光声现象的观察，我们将其命名为正向受激间极化散射。当两个频率偏移的激光信号被射入双折射小芯（直径1.8 μ m）光子晶体光纤的正交偏振导模时，会产生一个轴向移动的偏振条纹图案，其速度和间距取决于频率偏移。在频率偏置数ghz范围内，运动条纹的模式可以很好地匹配核心内紧密引导的扭转-径向声模式的相速度和轴向波长（3.9 mm）。强烈的光声相互作用随之而来，导致功率从高频（泵浦）模式到正交极化低频（斯托克斯）模式的有效非线性交换。一个全矢量理论被发展出来解释这些观测结果。
We report the observation of a novel nonlinear optoacoustic phenomenon, that we name forward stimulated interpolarization scattering. When two frequency-offset laser signals are colaunched into orthogonally polarized guided modes of a birefringent small-core (1.8 mu m diameter) photonic crystal fiber, a pattern of axially moving polarization fringes is produced, with a velocity and spacing that depends on the frequency offset. At values of frequency offset in the few-GHz range, the pattern of moving fringes can perfectly match the phase velocity and axial wavelength (3.9 mm) of the torsional-radial acoustic mode tightly guided in the core. An intense optoacoustic interaction ensues, leading to efficient nonlinear exchange of power from the higher frequency (pump) mode to the orthogonally polarized lower frequency (Stokes) mode. A full-vectorial theory is developed to explain the observations.