Magnetic-free non-reciprocity and isolation based on parametrically modulated coupled-resonator loops
Magnetic-free non-reciprocity and isolation based on parametrically modulated coupled-resonator loops
复制标题
基于参数调制耦合谐振器回路的无磁非互斥性和隔离功能
DOI：
10.1038/nphys3134
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发表时间：
2014-12-01
期刊：
影响因子：
19.6
通讯作者：
Alu, Andrea
中科院分区：
文献类型：
--
作者：
Estep, Nicholas A.;Sounas, Dimitrios L.;Alu, Andrea
对许多现代通信系统至关重要的非互易元件几乎完全基于磁光材料，严重限制了它们的适用性。实现无磁非互易的一种实用且廉价的途径可能会彻底改变射频和纳米光子通信网络。角动量偏置最近被提出作为实现在旋转介质中传播的声波隔离的一种手段(1)，并被设想为通向紧凑、线性集成的非互反电磁分量的途径(2),(3)。受这个概念的启发，我们在这里展示了一种亚波长，线性射频非互反环行器，无磁性材料和偏置。该方案是基于三个相同的，强和对称耦合谐振腔的参数调制。它们的谐振频率由具有相同振幅和相对相位差为120度的外部信号调制，赋予系统有效的电子角动量。我们观察到巨大的非互易性，在相反方向上的传输差异高达6个数量级。此外，该器件的拓扑结构是实时可调的，可以直接嵌入到传统的集成电路中。
Non-reciprocal components, which are essential to many modern communication systems, are almost exclusively based on magneto-optical materials, severely limiting their applicability. A practical and inexpensive route to magnetic-free non-reciprocity could revolutionize radio-frequency and nanophotonic communication networks. Angular-momentum biasing was recently proposed as a means of realizing isolation for sound waves travelling in a rotating medium(1), and envisaged as a path towards compact, linear integrated non-reciprocal electromagnetic components(2),(3). Inspired by this concept, here we demonstrate a subwavelength, linear radio-frequency non-reciprocal circulator free from magnetic materials and bias. The scheme is based on the parametric modulation of three identical, strongly and symmetrically coupled resonators. Their resonant frequencies are modulated by external signals with the same amplitude and a relative phase difference of 120 degrees, imparting an effective electronic angular momentum to the system. We observe giant non-reciprocity, with up to six orders of magnitude difference in transmission for opposite directions. Furthermore, the device topology is tunable in real time, and can be directly embedded in a conventional integrated circuit.