Near-Field Energy Extraction with Hyperbolic Metamaterials
- Publication date
- 2015
- Publisher
Abstract
Although
blackbody radiation described by Planck’s law is commonly regarded
as the maximum of thermal radiation, thermal energy transfer in the
near-field can exceed the blackbody limit due to the contribution
from evanescent waves. Here, we demonstrate experimentally a broadband
thermal energy extraction device based on hyperbolic metamaterials
that can significantly enhance near-field thermal energy transfer.
The thermal extractor made from hyperbolic metamaterials does not
absorb or emit any radiation but serves as a transparent pipe guiding
the radiative energy from the emitter. At the same gap between an
emitter and an absorber, we observe that near-field thermal energy
transfer with thermal extraction can be enhanced by around 1 order
of magnitude, compared to the case without thermal extraction. The
novel thermal extraction scheme has important practical implications
in a variety of technologies, e.g., thermophotovoltaic energy conversion,
radiative cooling, thermal infrared imaging, and heat assisted magnetic
recording