近日，以色列巴伊兰大学Zadok, Avi团队研究了低模光纤中的正向布里渊散射。该项研究成果发表在2025年7月9日出版的《光：科学与应用》杂志上。

前向布里渊散射是两个共传播光场在共同介质中以共散射模式耦合的光力学效应。自1985年以来，人们已经在标准光纤中研究了这种效应，但几乎所有的研究都局限于单光模式。单模光纤中的前向布里渊散射仅通过两类共散射模式发生：纯径向模式和双重方位角对称模式。共声模式只能在其截止频率处被激发，标准光纤中的共声频率被限制在600 MHz。

研究组通过分析，计算和实验将前向布里渊散射的研究扩展到少模光纤。测量是在一个商用的，现成的阶梯折射率光纤与标准包层通过三种光学模式。研究组首次证明了一阶和四阶方位对称的共谐模的刺激。合成频率高达1.8 GHz，在其截止频率以上激发共声模式。角动量在光波和光波的轨道自由度之间传递。这些结果扩展了对光纤中正向布里渊散射的理解和表述，并可能在光纤激光器、传感、非互易传播效应和量子态操纵中得到应用。

附：英文原文

Title: Forward Brillouin scattering in few-mode fibers

Author: Layosh, Elad, Zehavi, Elad, Bernstein, Alon, Hen, Mirit, Holsblat, Maayan, Pearl, Ori, Zadok, Avi

Issue&Volume: 2025-07-09

Abstract: Forward Brillouin scattering is an opto-mechanical effect in which two co-propagating optical fields couple with an acoustic mode in a common medium. The effect has been studied in standard optical fibers since 1985, however nearly all studies have been limited to the single optical mode regime. Forward Brillouin scattering in single-mode fibers takes place through two classes of acoustic modes only: purely radial ones and modes of two-fold azimuthal symmetry. Acoustic modes may only be stimulated at their cut-off frequencies, and the acoustic frequencies in standard fibers are limited to 600MHz. In this work, we extend the study of forward Brillouin scattering to few-mode optical fibers through analysis, calculations, and experiment. Measurements are performed in a commercial, off-the-shelf step-index fiber with standard cladding through three optical modes. We demonstrate for the first time the stimulation of acoustic modes with first-order and fourth-order azimuthal symmetries. Acoustic frequencies up to 1.8GHz are observed, and the acoustic modes are stimulated above their cut-off frequencies. Angular momentum is transferred between the orbital degrees of freedom of the optical and acoustic waves. The results extend the understanding and formulation of forward Brillouin scattering in optical fibers, and they may find applications in fiber lasers, sensing, non-reciprocal propagation effects, and quantum states manipulation.

DOI: 10.1038/s41377-025-01877-z

Source: https://www.nature.com/articles/s41377-025-01877-z