Self-Induced Passive Nonreciprocal Transmission by Nonlinear Bifacial Dielectric Metasurfaces
Self-Induced Passive Nonreciprocal Transmission by Nonlinear Bifacial Dielectric Metasurfaces
复制标题
DOI：
10.1103/physrevapplied.13.054056
复制
发表时间：
2020-05-22
影响因子：
4.6
通讯作者：
Argyropoulos, Christos
中科院分区：
文献类型：
--
作者：
Jin, Boyuan;Argyropoulos, Christos
打破洛仑兹互易定律是一项不平凡的任务，因为它通常需要庞大的磁铁或复杂的时间调制动态技术来完成。在这项工作中，我们提出了一个简单而紧凑的设计，非线性双面介质metasurface实现强大的自诱导无源非互易传输，而无需使用外部偏置。所提出的设计是自由空间光学应用的理想选择，可以在两种入射偏振下工作，并且需要非常低的输入激发功率来达到非互易机制。它是由两个被动的硅基超颖表面表现出法诺和洛伦兹共振嵌入在一个玻璃基板。高度不对称的场增强实现与建议的设计，导致在低激发强度，由于大的克尔非线性硅强非互易性。此外，级联的设计，提出了进一步降低插入损耗，扩大非互易强度范围，并通过提高传输对比度提高隔离比。最后，它表明，所提出的非线性超颖表面是强大的制造缺陷方面，可以实现较大的隔离相对较宽的输入功率范围内，即使在两个入射波同时从两个方向撞击的情况下。目前的工作预计将导致几个紧凑的非互易纳米光子器件，如全光二极管，隔离器，环行器，和敏感的光学元件的防反射保护层。
The breaking of the Lorentz reciprocity law is a nontrivial task, since it usually requires bulky magnets or complicated time-modulation dynamic techniques to be accomplished. In this work, we present a simple and compact design of a nonlinear bifacial dielectric metasurface to achieve strong self-induced passive nonreciprocal transmission without the use of external biases. The proposed design is ideal for free-space-optics applications, can operate under both incident polarizations, and requires very low input excitation power to reach the nonreciprocal regime. It is composed of two passive silicon-based metasurfaces exhibiting Fano and Lorentzian resonances embedded in an ultrathin glass substrate. Highly asymmetric field enhancement is achieved with the proposed design that leads to strong nonreciprocity at low excitation intensities due to the large Kerr nonlinearity of silicon. Moreover, cascade designs are presented to further reduce the insertion loss, broaden the nonreciprocal intensity range, and increase the isolation ratio by enhancement of the transmission contrast. Finally, it is demonstrated that the proposed nonlinear metasurface is robust with regard to fabrication imperfections and can achieve large isolation for a relatively broad input power range even in the case of two incident waves impinging at the same time from both directions. The current work is expected to lead to several compact nonreciprocal nanophotonic devices, such as all-optical diodes, isolators, circulators, and ultrathin protective layers for sensitive optical components.