近日，中国科学技术大学的邹长铃及其研究小组与山西大学的李刚等人合作并取得一项新进展。经过不懈努力，他们揭示自诱导光学非互易性。相关研究成果已于2025年1月2日在国际知名学术期刊《光：科学与应用》上发表。

本文提出了一种光学介质的非线性非互易易感性机制，并在实验上实现了无需任何外部偏置场的自诱导光学信号隔离。输入信号的自诱导隔离表现出了极高的隔离比（63.4dB）、60dB隔离带宽（2.1GHz）以及低插入损耗（约1dB）。此外，这一新机制还催生了包括偏振纯化和非互易杠杆效应在内的新型功能光学器件。

通过引入非对称腔，研究人员实现了一种完整的无源隔离器。实验证明，70微瓦的信号即可利用非互易性，对功率高出100倍的反向激光实现30dB的隔离。所展示的非线性非互易介质为研究人员提供了一种控制光的通用工具，加深了研究人员对光与物质相互作用的理解，并使得从拓扑光子学到网络中的单向量子信息传输等应用成为可能。

据悉，非互易光学元件在光学应用中不可或缺，而无需磁场即可实现这类元件的技术在光子学领域引起了越来越多的研究兴趣。通过引入光学介质的空间-时间调制，或将克尔型光学非线性与光子结构中的空间不对称性相结合，已经取得了令人振奋的实验进展。然而，第一种方法需要额外的驱动场，而第二种方法则无法同时实现噪声隔离和信号传输。

附：英文原文

Title: Self-induced optical non-reciprocity

Author: Wang, Zhu-Bo, Zhang, Yan-Lei, Hu, Xin-Xin, Chen, Guang-Jie, Li, Ming, Yang, Peng-Fei, Zou, Xu-Bo, Zhang, Peng-Fei, Dong, Chun-Hua, Li, Gang, Zhang, Tian-Cai, Guo, Guang-Can, Zou, Chang-Ling

Issue&Volume: 2025-01-02

Abstract: Non-reciprocal optical components are indispensable in optical applications, and their realization without any magnetic field has attracted increasing research interest in photonics. Exciting experimental progress has been achieved by either introducing spatial-temporal modulation of the optical medium or combining Kerr-type optical nonlinearity with spatial asymmetry in photonic structures. However, extra driving fields are required for the first approach, while the isolation of noise and the transmission of the signal cannot be simultaneously achieved for the other approach. Here, we propose the mechanism of nonlinear non-reciprocal susceptibility for optical media and experimentally realize the self-induced isolation of optical signals without any external bias field. The self-induced isolation by the input signal is demonstrated with an extremely high isolation ratio of 63.4dB, a bandwidth of 2.1GHz for 60dB isolation, and a low insertion loss of ~1dB. Furthermore, the new mechanism allows novel functional optical devices, including polarization purification and non-reciprocal leverage. A complete passive isolator is realized by introducing an asymmetry cavity. It is demonstrated that the 70μW signal could lever the non-reciprocity and realize a 30dB isolation of the backward laser with a power 100times higher. The demonstrated nonlinear non-reciprocal medium provides a versatile tool to control light and deepen our understanding of light-matter interactions and enables applications ranging from topological photonics to unidirectional quantum information transfer in a network.

DOI: 10.1038/s41377-024-01692-y

Source: https://www.nature.com/articles/s41377-024-01692-y