In an ideal perfectly straight multimode fiber with a circular core, the symmetry ensures that rotating the input wave front leads to a corresponding rotation of the output wave front. This invariant property, known as the rotational memory effect (RME), remains independent of the typically unknown output profile. The RME thus offers significant potential for imaging and telecommunication applications. However, in real-life fibers, this effect is degraded by intrinsic imperfections and external perturbations, and is challenging to observe because of its acute sensitivity to misalignments and aberrations in the optical setup. Building on a previously established method for precisely estimating fiber transmission properties, we demonstrate an accurate extraction of RME properties. Additionally, we introduce a comprehensive theoretical framework for both qualitative and quantitative analysis, which specifically links the angular-dependent correlation of the RME to the core deformation’s geometrical properties and the fiber’s mode characteristics. Our theoretical predictions align well with experimental data and simulations for various amounts of fiber distorsion. Finally, we demonstrate the ability to engineer wave fronts with significantly enhanced correlation across all rotation angles. This work enables accurate characterization of distributed disorder from the fabrication process and facilitates calibration-free imaging in multimode fibers.

中文翻译：

---

多模光纤中旋转记忆效应的表征和开发


在具有圆形纤芯的理想完美笔直多模光纤中，对称性确保旋转输入波前会导致输出波前的相应旋转。这种不变的属性，称为旋转记忆效应 （RME），与通常未知的输出配置文件无关。因此，RME为成像和电信应用提供了巨大的潜力。然而，在现实生活中的光纤中，这种效应会因固有缺陷和外部扰动而降低，并且由于其对光学设置中的错位和像差非常敏感，因此难以观察。在先前建立的精确估计光纤传输特性的方法的基础上，我们展示了 RME 特性的准确提取。此外，我们引入了一个用于定性和定量分析的综合理论框架，该框架专门将 RME 的角度依赖性相关性与纤芯变形的几何特性和光纤的模式特性联系起来。我们的理论预测与各种纤维扭曲量的实验数据和模拟非常吻合。最后，我们展示了在所有旋转角度上具有显著增强相关性的波前设计能力。这项工作能够准确表征制造过程中的分布式无序，并有助于多模光纤中的免校准成像。