美国耶鲁大学Peter T. Rakich团队研究了太赫兹带宽非磁性隔离器。该项研究成果发表在2025年4月15日出版的《自然—光子学》杂志上。
宽带光隔离器对于几乎所有光子系统的稳健运行至关重要。然而，由于磁性介质与这些电路技术的不兼容性，它们很难以集成形式实现。研究组首次演示了具有太赫兹级光带宽的集成非磁性光隔离器。
该系统包括两个声光分束器，它们创建了一个非互易多模干涉仪，表现出高对比度、非互易光传输。研究组通过精确平衡干涉仪路径的群延迟，大大提高了该系统的隔离带宽。使用这种方法，他们展示了集成的非磁性隔离器，其光学对比度高达24.5 dB，插入损耗低至-2.16 dB，光学带宽高达2 THz（16 nm）。
研究组还表明，通过调整用于驱动声光分束器的微波信号的相对相位，可以快速重新配置光隔离的中心频率和方向。凭借其互补的金属-氧化物-半导体兼容性、宽带操作、低损耗和快速可重构性，这种集成隔离器解决了在芯片上集成各种光子功能的关键障碍。
附：英文原文
Title: A terahertz-bandwidth non-magnetic isolator
Author: Cheng, Haotian, Zhou, Yishu, Ruesink, Freek, Pavlovich, Margaret, Gertler, Shai, Starbuck, Andrew L., Leenheer, Andrew J., Pomerene, Andrew T., Trotter, Douglas C., Dallo, Christina, Boady, Matthew, Musick, Katherine M., Gehl, Michael, Kodigala, Ashok, Eichenfield, Matt, Lentine, Anthony L., Otterstrom, Nils T., Rakich, Peter T.
Issue&Volume: 2025-04-15
Abstract: Wideband optical isolators are critical for the robust operation of virtually all photonic systems. However, they have been challenging to realize in the integrated form due to the incompatibility of magnetic media with these circuit technologies. Here we present the first-ever demonstration of an integrated non-magnetic optical isolator with terahertz-level optical bandwidth. The system comprises two acousto-optic beamsplitters that create a non-reciprocal multimode interferometer exhibiting high-contrast, non-reciprocal light transmission. We dramatically enhance the isolation bandwidth of this system by precisely balancing the group delays of the paths of the interferometer. Using this approach, we demonstrate integrated non-magnetic isolators with an optical contrast as high as 24.5dB, insertion losses as low as 2.16dB and optical bandwidths as high as 2THz (16nm). We also show that the centre frequency and direction of optical isolation are rapidly reconfigurable by tuning the relative phase of the microwave signals used to drive the acousto-optic beamsplitters. With their complementary metal–oxide–semiconductor compatibility, wideband operation, low losses and rapid reconfigurability, such integrated isolators address a key barrier to the integration of a wide range of photonic functionalities on a chip.
DOI: 10.1038/s41566-025-01663-8
Source: https://www.nature.com/articles/s41566-025-01663-8