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arXiv 2011.04489physics.opticsphysics.class-ph
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时间调制介质中的强空间色散

Strong Spatial Dispersion in Time-Modulated Dielectric Media

Dani Torrent

摘要:

提出了时间调制介质的有效介质描述。通过在一个调制周期上取平均场,导出它们之间的关系,从而定义不同的本构参数。在最一般的情况下,它被发现,有效的材料是通过一个空间和时间色散的横向介电函数和一个恒定的纵向介电函数。还发现,与其波数依赖性(空间色散)相比,前者的频率依赖性较弱。这种空间色散的不同的物理后果进行了讨论,特别强调在弱色散近似,限制中,它被发现的有效材料的行为作为一个共振和各向同性磁介质没有额外的纵向模式,因为它是常见的空间色散材料。因此,时间相关介质开辟了一种设计动态可调超材料的替代方法。

英文摘要:

We present an effective medium description of time-modulated dielectric media. By taking the averaged fields over one modulation period, the relationship between them is derived, defining therefore the different constitutive parameters. In the most general situation, it is found that the effective material is described by means of a spatially and temporally dispersive transverse dielectric function and a constant longitudinal dielectric function. It has been also found that the frequency dependence in the former is weak, in comparison with its wavenumber-dependence (spatial dispersion). Different physical consequences of this spatial dispersion are discussed, with special emphasis in the weak dispersion approximation, limit in which it is found that the effective material behaves as a resonant and isotropic magnetodielectric medium with no additional longitudinal mode, as it is commonly found in spatially dispersive materials. Time-dependent media opens therefore an alternative way of designing dynamically tunable metamaterials.

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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