Highly coherent thermal emission obtained by plasmonic bandgap structures

Abstract

We demonstrate an extraordinary quasimonochromatic thermal emission with high spatial coherence length (lc>2400λ) and a quality factor Q=2320 at radiation frequencies that are much smaller than the plasma frequency of metal (ω≪ωp). This emission is achieved by forming a plasmonic bandgap, which is obtained by a periodic structure on a metallic surface. Such a structure modifies the dynamics of the surface wave and results in a van Hove singularity [Van Hove, Phys. Rev. 89, 1189 (1953)] in the spectral density of states while maintaining a large coherence length.

Slow surface phonon polaritons for sensing in the midinfrared spectrum

“…Several mechanisms were proposed to increase the DOS by changing the dynamics of the delocalized surface waves. These changes can be due to tailoring the plasma frequency within a metamaterial, 8 localization of SPPs in microcavities, 9 surface enhanced infrared absorption, 10 confined waveguiding plasmonic modes in ultrathin film, 11 plasmonic bandgap structure, 12 and standing waves coupled SPPs. 13 In this letter, we propose utilizing a different type of surface waves known as surface phonon polaritons ͑SPhPs͒ for refractive index sensing in the mid-IR region.…”

Radiative energy and momentum transfer for various spherical shapes: A single sphere, a bubble, a spherical shell, and a coated sphere

“…For example, Rytov investigated the thermal radiation of a spherical body based on his proposed formalism of electromagnetic fluctuations, 2 Eckhardt summarized and compared two methods, Rytov's fluctuation-dissipation theorem and Langevin theory (stochastic electrodynamics) to study the radiative heat transfer, 13 Kattawar and Eisner used Rytov's formalism to calculate the radiant power from a homogeneous isothermal sphere of arbitrary size, 14 Kr€ uger et al discussed radiative heat transfer and Casimir force from a cylinder emphasizing its polarized nature, 15 Golyk et al explored the radiation from a long cylinder at uniform temperature when the radius of the cylinder is much smaller than the thermal wavelength, 16 Barabanenkov and Barabanenkov explored the coherent effect of thermal microwave radiation from a heated body, 17 and others. [18][19][20][21][22] Near-field radiative energy and momentum transfer between flat and curved surfaces has been studied for the past years. Enhancement of radiative energy transfer, wavelength selectivity, and size and scale dependence are typical characteristics of near-field phenomena which make it more interesting.…”

Optical resonances in the scattering of light from a nanostructured metal surface: A three-dimensional numerical study

“…1-3 The large plethora of resonant phenomena has been revealed and discussed such as extraordinary transmission through the subwavelength hole arrays [4][5][6][7][8][9][10][11] and metallic grating, 5,[12][13][14][15] absorption of the incoming radiation, [16][17][18][19][20] and coherent thermal emission. [21][22][23] The resonances represent sharp features in the frequency dependence of the scattering matrix. From the time dependent point of view, they reflect the existence of the long-lived ͑slowly decaying͒ electromagnetic near-field modes "trapped" by the structure.…”