Liu Kexin, He Sailing
Department of Electromagnetic Engineering, School of Electrical Engineering, KTH Royal Institute of Technology, Stockholm S-100 44, Sweden.
Centre for Optical and Electromagnetic Research, State Key Laboratory of Modern Optical Instrumentation, JORCEP (Sino-Swedish Joint Research Center of Photonics), Zhejiang University, Hangzhou 310058, China.
Sci Rep. 2016 Jul 25;6:30206. doi: 10.1038/srep30206.
The concept of a "trapped rainbow" has generated considerable interest for optical data storage and processing. It aims to trap different frequency components of the wave packet at different positions permanently. However, all the previously proposed structures cannot truly achieve this effect, due to the difficulties in suppressing the reflection caused by strong intermodal coupling and distinguishing different frequency components simultaneously. In this article, we found a physical mechanism to achieve a truly "trapped rainbow" storage of electromagnetic wave. We utilize nonreciprocal waveguides under a tapered magnetic field to achieve this and such a trapping effect is stable even under fabrication disorders. We also observe hot spots and relatively long duration time of the trapped wave around critical positions through frequency domain and time domain simulations. The physical mechanism we found has a variety of potential applications ranging from wave harvesting and storage to nonlinearity enhancement.
“捕获彩虹”的概念已引起光学数据存储和处理领域的广泛关注。其目的是将波包的不同频率成分永久地捕获在不同位置。然而，由于难以抑制强模间耦合引起的反射并同时区分不同频率成分，所有先前提出的结构都无法真正实现这种效果。在本文中，我们发现了一种实现电磁波真正“捕获彩虹”存储的物理机制。我们利用锥形磁场下的非互易波导来实现这一点，并且即使在制造缺陷的情况下，这种捕获效果也是稳定的。我们还通过频域和时域模拟观察到临界位置周围捕获波的热点和相对较长的持续时间。我们发现的物理机制具有从波收集和存储到非线性增强等多种潜在应用。
