Overcoming black body radiation limit in free space: Metamaterial superemitter

Research output: Contribution to journalArticle

Researchers

Research units

  • Universidade de Coimbra

Abstract

Here, we demonstrate that the power spectral density of thermal radiation at a specific wavelength produced by a body of finite dimensions set up in free space under a fixed temperature could be made theoretically arbitrary high, if one could realize double negative metamaterials with arbitrary small loss and arbitrary high absolute values of permittivity and permeability (at a given frequency). This result refutes the widespread belief that Planck's law itself sets a hard upper limit on the spectral density of power emitted by a finite macroscopic body whose size is much greater than the wavelength. Here we propose a physical realization of a metamaterial emitter whose spectral emissivity can be greater than that of the ideal black body under the same conditions. Due to the reciprocity between the heat emission and absorption processes such cooled down superemitter also acts as an optimal sink for the thermal radiation - the 'thermal black hole' - which outperforms Kirchhoff-Planck's black body which can absorb only the rays directly incident on its surface. The results may open a possibility to realize narrowband super-Planckian thermal radiators and absorbers for future thermo-photovoltaic systems and other devices.

Details

Original languageEnglish
Article number013034
JournalNew Journal of Physics
Volume18
Issue number1
Publication statusPublished - 1 Jan 2016
MoE publication typeA1 Journal article-refereed

    Research areas

  • black body, metamaterial, thermal radiation

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