Magnetic field free circularly polarized thermal emission from a chiral metasurface
Magnetic field free circularly polarized thermal emission from a chiral metasurface
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DOI：
10.1103/physrevb.98.235416
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发表时间：
2018-12-17
影响因子：
3.7
通讯作者：
Tikhodeev, S. G.
中科院分区：
文献类型：
--
作者：
Dyakov, S. A.;Semenenko, V. A.;Tikhodeev, S. G.
无序放置的非共振辐射体的热辐射是宽带非相干的各向同性热辐射。在外部磁场中，来自任何源的热辐射都是圆偏振的。在这里，我们提出了一种热辐射源，它发出圆偏振辐射，而不是放置在磁场中。热源由一个平板波导与蚀刻的手征超颖表面的四重旋转对称。利用傅里叶模态法分析了结构的本征模态和发射率谱。我们证明，由于没有镜像对称的超颖表面的本征模以及热产生的电磁波成为圆偏振。在本文中，我们详细讨论了这种现象的起源。我们证明，在优化的结构中的圆偏振度可以高达0.87。
Thermal radiation from bulk disorderly placed nonresonant emitters is incoherent broadband and isotropic. In an external magnetic field the thermal radiation from any source is circularly polarized. Here we propose a thermal radiation source which emits circularly polarized radiation and which is not placed in a magnetic field. The thermal source consists of a slab waveguide with etched chiral metasurface of fourfold rotational symmetry. Using the Fourier modal method we analyze the eigenmodes of the structure and the emissivity spectra. We demonstrate that due to the absence of a mirror symmetry of the metasurface its eigenmodes as well as the thermally generated electromagnetic waves become circularly polarized. In this paper we discuss the origin of this phenomenon in detail. We demonstrate that the degree of circular polarization in an optimized structure can be as high as 0.87.