近日，以色列本-古里安大学Yshai Avishai团队研究了光学中的几何相位：在螺旋光纤中传播的光的偏振。2025年3月27日出版的《物理评论A》杂志发表了这项最新研究成果。

光学几何相位（OGP）与光的偏振直接相关。课题组研究了单模光束在缠绕成圆形螺旋结构的单模光纤中传播时，在有和没有应力诱导双折射的情况下，OGP发生的物理原理。还讨论了螺旋光纤的曲率和扭转对偏振矢量旋转和相关OGP的影响，推导了进入螺旋光纤的光的任何初始偏振态的偏振矢量和斯托克斯参数的解析表达式，以及作为螺旋弧长函数的光的OGP的解析表达式。

此外，还导出了取决于最终OGP的初始和最终光束叠加的强度，分析了OGP与庞加莱球上绘制的螺旋切线矢量所对立体角之间的关系，并考虑了指定螺旋纤维几何形状和材料特性的参数波动对OGP的影响。研究组还指出，OGP是一个几何相，而不是拓扑相，因此在拓扑上没有受到保护，无法抵御可能对容错产生不利影响的局部扰动。

附：英文原文

Title: Geometric phases in optics: Polarization of light propagating in helical optical fibers

Author: Y. B. Band, Igor Kuzmenko, Yshai Avishai

Issue&Volume: 2025/03/27

Abstract: The optical geometric phase (OGP) is directly associated with the polarization of light. We investigate the physical principles underlying the occurrence of the OGP for a single-mode light beam propagating in a single-mode optical fiber wound into a circular helix configuration, with and without stress-induced birefringence. The effects of the curvature and torsion of the helical fiber on the rotation of the polarization vector and the associated OGP are discussed. Analytic expressions are derived for the polarization vector and Stokes parameters for any initial polarization state of the light entering the helical fiber, as well as for the OGP of the light as a function of helix arclength. Additionally, the intensity of a superposition of the initial and final beams, which depends on the final OGP, is derived. Furthermore, the relationship between the OGP and the solid angle subtended by the tangent vector of the helix plotted on the Poincaré sphere is analyzed and the effects of fluctuations of the parameters specifying the geometry and the material characteristics of the helical fiber on the OGP are considered. We also point out that the OGP is a geometric phase and not a topological phase and therefore is not topologically protected against local perturbations which can adversely affect fault tolerance.

DOI: 10.1103/PhysRevA.111.033530

Source: https://journals.aps.org/pra/abstract/10.1103/PhysRevA.111.033530