Zhong Qi, Zhao Haoqi, Feng Liang, Busch Kurt, Özdemir Şahin K, El-Ganainy Ramy
Department of Physics, Michigan Technological University, Houghton, MI 49931, USA.
Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA 19104, USA.
Nanophotonics. 2022 Aug 19;11(19):4427-4437. doi: 10.1515/nanoph-2022-0304. eCollection 2022 Sep.
Optical resonators are structures that utilize wave interference and feedback to confine light in all three dimensions. Depending on the feedback mechanism, resonators can support either standing- or traveling-wave modes. Over the years, the distinction between these two different types of modes has become so prevalent that nowadays it is one of the main characteristics for classifying optical resonators. Here, we show that an intermediate link between these two rather different groups exists. In particular, we introduce a new class of photonic resonators that supports a hybrid optical mode, i.e. at one location along the resonator the electromagnetic fields associated with the mode feature a purely standing-wave pattern, while at a different location, the fields of the same mode represent a pure traveling wave. The proposed concept is general and can be implemented using chip-scale photonics as well as free-space optics. Moreover, it can be extended to other wave phenomena such as microwaves and acoustics.
光学谐振器是利用波的干涉和反馈在所有三个维度上限制光的结构。根据反馈机制，谐振器可以支持驻波模式或行波模式。多年来，这两种不同类型模式之间的区别已经变得非常普遍，以至于如今它是光学谐振器分类的主要特征之一。在这里，我们表明在这两个截然不同的类别之间存在一个中间环节。具体而言，我们引入了一类新的光子谐振器，它支持一种混合光学模式，即在沿着谐振器的一个位置，与该模式相关的电磁场具有纯驻波模式，而在不同位置，同一模式的场代表纯行波。所提出的概念具有普遍性，可以使用芯片级光子学以及自由空间光学来实现。此外，它可以扩展到其他波动现象，如微波和声学。
