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arXiv 2108.01007physics.opticsphysics.app-ph
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具有增益和损耗的时间超材料

Temporal metamaterials with gain and loss

Victor Pacheco-Peña, Nader Engheta

摘要:

在有损耗和有增益的系统中操纵波-物质相互作用已经开辟了随意控制波传播的新机制。在过去的几年中,通过利用从量子物理学中得到启发的宇称时间(PT)对称性概念,已经研究了具有空间非均匀损耗和增益的超材料和超表面。在这项工作中,我们从理论上研究了空间无界的超材料具有时间调制的介电常数,其虚部在时间上调制,以诱导损耗和增益,而实部保持不变的光-物质相互作用的控制。我们在数值上和理论上证明了这种具有损耗和增益的时间调制多阶超材料可以等效于具有由时间阶跃函数建模的有效介电常数的时间有效超材料。有趣的是,它示出了如何的单色电磁波的振幅在这样的时间超材料内旅行可以经历时空衰减或放大取决于添加到系统中的损失和增益的值,而其波数被保存。我们设想,我们的研究结果可能会开辟新的途径,在信号放大和损失减轻的时间超材料的潜在应用的探索。

英文摘要:

Manipulation of wave-matter interactions in systems with loss and gain have opened new mechanisms to control wave propagation at will. Metamaterials and metasurfaces having spatially inhomogeneous loss and gain have been studied in the past few years by exploiting parity-time (PT) symmetry concepts inspired from quantum-physics. In this work we theoretically study the control of light-matter interactions in spatially unbounded metamaterials having a time-modulated permittivity whose imaginary part is temporally modulated to induce loss and gain, while the real part stays unchanged. We show both numerically and theoretically how such temporally modulated multistepped metamaterials with loss and gain can be equivalent to a temporal effective metamaterial having an effective permittivity modelled by a step function in time. Interestingly, it is shown how the amplitude of a monochromatic electromagnetic wave traveling inside such temporal metamaterials can experience spatiotemporal decay or amplification depending on the values of loss and gain added into the system, while its wavenumber is preserved. We envision that our findings may open new avenues in exploration of potential applications of temporal metamaterials in signal amplification and loss mitigation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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