近日，美国纽约城市大学的Andrea Alu及其研究团队取得一项新进展。经过不懈努力，他们实现无反射散射模式混沌光学微腔的相干控制。相关研究成果已于2023年11月2日在国际知名学术期刊《自然—物理学》上发表。

该研究团队成功地在涉及超过一千种光学模式的混沌光子微腔中证实了无反射散射模式的存在。研究人员采用准正常模式扩展的方法，模拟了硅体育场微腔中的光场，成功在输入端口捕获了密集的反射零，与无反射散射模式密切相关。此外，他们还观察到了电信波段的无反射散射模式的非厄米简并现象，实现了对空腔中光辐射的有效动态控制。

据悉，近年来非厄米波工程在光子学领域引发了极大的研究兴趣。其中，一些突出的非厄米现象包括相干完全吸收及其产生、无反射散射模式（即输入端口的电磁散射在与泄漏到输出端口的功率的临界耦合作用下被抑制）以及干扰现象。这些概念非常适用于实现对吸收、散射和辐射的实时动态控制。然而，在开放系统和多输入复杂光子平台中，尚未观察到无反射散射模式。

附：英文原文

Title: Coherent control of chaotic optical microcavity with reflectionless scattering modes

Author: Jiang, Xuefeng, Yin, Shixiong, Li, Huanan, Quan, Jiamin, Goh, Heedong, Cotrufo, Michele, Kullig, Julius, Wiersig, Jan, Alu, Andrea

Issue&Volume: 2023-11-02

Abstract: Non-Hermitian wave engineering has attracted a surge of interest in photonics in recent years. Prominent non-Hermitian phenomena include coherent perfect absorption and its generalization, reflectionless scattering modes, in which electromagnetic scattering at the input ports is suppressed due to critical coupling with the power leaked to output ports, and interference phenomena. These concepts are ideally suited to enable real-time dynamic control over absorption, scattering and radiation. Nonetheless, reflectionless scattering modes have not been observed in complex photonic platforms involving open systems and multiple inputs. Here we demonstrate the emergence of reflectionless scattering modes in a chaotic photonic microcavity involving over a thousand optical modes. We model the optical fields in a silicon stadium microcavity within a quasi-normal mode expansion, which is able to capture a dense family of reflection zeros at the input ports, associated with reflectionless scattering modes. We observe non-Hermitian degeneracies of reflectionless scattering modes in the telecommunication wavelength band, enabling efficient dynamic control over light radiation from the cavity.

DOI: 10.1038/s41567-023-02242-w

Source: https://www.nature.com/articles/s41567-023-02242-w