近日，美国特拉华大学的Tingyi Gu及其研究小组与纽约城市大学的Andrea Alu等人合作并取得一项新进展。经过不懈努力，他们揭示微谐振器中的手性异常点增强主动调谐和非互易性。相关研究成果已于2025年1月9日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队使用非对称米氏散射体来打破微谐振器的旋转对称性，以展示跨越手性异常点（EP）的确定性热调谐，并演示EP介导的手性光学非线性响应和高效的电光调谐。研究结果表明，在吉赫兹频率和与CMOS兼容的电压水平下，实现了对比度高达17dB的非对称电光调制。这种晶圆级的手性电光调制器纳米制造技术以及基于手性EP的定制调谐，可能会为量子信息处理、电磁波控制和光学互连中的微谐振器带来新的功能。

据悉，异常点（EPs）在机械、声学、等离子体和光子系统中已得到广泛研究。然而，关于EPs在调节光学器件动态可调性中的作用，人们知之甚少。最近，一种被称为手性EPs的特定类型EPs，因其在控制光流和构建具有更高响应性的传感器方面的潜力而备受关注。最近通过光刻技术在谐振器边缘定义对称米氏散射体来实现手性EPs的方法，不仅为研究手性EPs提供了亟需的机械稳定性，还有助于减少由纳米制造缺陷引起的损失，从而促进了手性EPs及其对谐振器动力学和可调性贡献的原位研究。

附：英文原文

Title: Chiral exceptional point enhanced active tuning and nonreciprocity in micro-resonators

Author: Lee, Hwaseob, Chang, Lorry, Kecebas, Ali, Mao, Dun, Xiao, Yahui, Li, Tiantian, Al, Andrea, zdemir, Sahin K., Gu, Tingyi

Issue&Volume: 2025-01-09

Abstract: Exceptional points (EPs) have been extensively explored in mechanical, acoustic, plasmonic, and photonic systems. However, little is known about the role of EPs in tailoring the dynamic tunability of optical devices. A specific type of EPs known as chiral EPs has recently attracted much attention for controlling the flow of light and for building sensors with better responsivity. A recently demonstrated route to chiral EPs via lithographically defined symmetric Mie scatterers on the rim of resonators has not only provided the much-needed mechanical stability for studying chiral EPs, but also helped reduce losses originating from nanofabrication imperfections, facilitating the in-situ study of chiral EPs and their contribution to the dynamics and tunability of resonators. Here, we use asymmetric Mie scatterers to break the rotational symmetry of a microresonator, to demonstrate deterministic thermal tuning across a chiral EP, and to demonstrate EP-mediated chiral optical nonlinear response and efficient electro-optic tuning. Our results indicate asymmetric electro-optic modulation with up to 17dB contrast at GHz and CMOS-compatible voltage levels. Such wafer-scale nano-manufacturing of chiral electro-optic modulators and the chiral EP-tailored tunning may facilitate new micro-resonator functionalities in quantum information processing, electromagnetic wave control, and optical interconnects.

DOI: 10.1038/s41377-024-01686-w

Source: https://www.nature.com/articles/s41377-024-01686-w