Universal modal radiation laws for all thermal emitters
Abstract
Radiation laws must relate the fraction of incident radiation absorbed by an object and the amount of radiation emitted when it is hot so that objects can come to the same temperature just by exchanging electromagnetic radiation. Such laws are fundamentally important and set limits to practical applications such as in the conversion of light to electricity and in heat and thermal management generally. Kirchhoff's classic results work well in many situations, but fail in others (specifically for "nonreciprocal" materials), and were derived using simplified models that do not apply to modern nanotechnology and light beams. We derive revised versions of laws that avoid these problems and discover additional and unexpected radiation laws that substantially expand the fundamental relations between optical absorption and emission.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- April 2017
- DOI:
- 10.1073/pnas.1701606114
- Bibcode:
- 2017PNAS..114.4336M
- Keywords:
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- Kirchhoff radiation laws;
- thermal radiation;
- optical modes;
- solar energy conversion;
- mode conversion