Opto-mechanical interactions in guided wave media are drawing great interest in fundamental research and applications. Forward stimulated Brillouin scattering, in particular, is widely investigated in optical fibres and photonic integrated circuits. In this work, we report a comprehensive study of forward stimulated Brillouin scattering over standard, panda-type polarization maintaining fibres. We distinguish between intra-polarization scattering, in which two pump tones are co-polarized along one principal axis, and inter-polarization processes driven by orthogonally polarized pump waves. Both processes are quantified in analysis, calculations and experiment. Inter-modal scattering, in particular, introduces cross-polarization switching of probe waves that is non-reciprocal. Switching takes place in multiple wavelength windows. The results provide a first demonstration of opto-mechanical non-reciprocity of forward scatter in standard fibre. The inter-polarization process is applicable to distributed sensors of media outside the cladding and coating boundaries, where light cannot reach. The process may be scaled towards forward Brillouin lasers, optical isolators and circulators and narrowband microwave-photonic filters over longer sections of off-the-shelf polarization maintaining fibres.

导波介质中的光机械相互作用引起了基础研究和应用的极大兴趣。特别是前向受激布里渊散射在光纤和光子集成电路中得到了广泛的研究。在这项工作中，我们报告了对标准熊猫型保偏光纤的前向受激布里渊散射的综合研究。我们区分了偏振内散射，其中两个泵浦音沿一个主轴共偏振，以及由正交偏振泵浦波驱动的偏振间过程。这两个过程都在分析、计算和实验中量化。特别是模式间散射引入了非互易的探测波的交叉极化切换。切换发生在多个波长窗口中。结果首次证明了标准光纤中前向散射的光机械非互易性。内极化过程适用于光无法到达的包层和涂层边界之外的分布式介质传感器。该工艺可以扩展到前向布里渊激光器、光隔离器和循环器以及窄带微波光子滤波器，覆盖更长的现成保偏光纤。