Title: | An In-situ and Direct Confirmation of Super-Planckian Thermal Radiation Emitted From a Metallic Photonic-Crystal at Optical Wavelengths |
Authors: | Lin, Shawn-Yu Hsieh, Mei-Li John, Sajeev Frey, B. Bur, James A. Luk, Ting-Shan Wang, Xuanjie Narayanan, Shankar 光電工程學系 Department of Photonics |
Issue Date: | 23-Mar-2020 |
Abstract: | Planck's law predicts the distribution of radiation energy, color and intensity, emitted from a hot object at thermal equilibrium. The Law also sets the upper limit of radiation intensity, the blackbody limit. Recent experiments reveal that micro-structured tungsten can exhibit significant deviation from the blackbody spectrum. However, whether thermal radiation with weak non-equilibrium pumping can exceed the blackbody limit in the far field remains un-answered experimentally. Here, we compare thermal radiation from a micro-cavity/tungsten photonic crystal (W-PC) and a blackbody, which are both measured from the same sample and also in-situ. We show that thermal radiation can exceed the blackbody limit by >8 times at lambda = 1.7 mu m resonant wavelength in the far-field. Our observation is consistent with a recent calculation by Wang and John performed for a 2D W-PC filament. This finding is attributed to non-equilibrium excitation of localized surface plasmon resonances coupled to nonlinear oscillators and the propagation of the electromagnetic waves through non-linear Bloch waves of the W-PC structure. This discovery could help create super-intense narrow band thermal light sources and even an infrared emitter with a laser-like input-output characteristic. |
URI: | http://dx.doi.org/10.1038/s41598-020-62063-2 http://hdl.handle.net/11536/155467 |
ISSN: | 2045-2322 |
DOI: | 10.1038/s41598-020-62063-2 |
Journal: | SCIENTIFIC REPORTS |
Volume: | 10 |
Issue: | 1 |
Begin Page: | 0 |
End Page: | 0 |
Appears in Collections: | Articles |