Active Thermal Extraction of Near-field Thermal Radiation

TL;DR

This paper introduces an active method to extract near-field thermal radiation into the far-field using a laser gain medium, enabling enhanced control over thermal emission for applications in thermal management.

Contribution

It proposes and numerically demonstrates a novel active scheme leveraging laser gain media to convert near-field thermal modes into far-field radiation, surpassing traditional limitations.

Findings

Successful numerical demonstration of mode extraction

Enhanced far-field thermal radiation control

Potential applications in thermal management

Abstract

Radiative heat transport between materials supporting surface-phonon polaritons is greatly enhanced when the materials are placed at sub-wavelength separation as a result of the contribution of near-field surface modes. However, the enhancement is limited to small separations due to the evanescent decay of the surface waves. In this work, we propose and numerically demonstrate an active scheme to extract these modes to the far-field. Our approach exploits the monochromatic nature of near-field thermal radiation to drive a transition in a laser gain medium, which, when coupled with external optical pumping, allows the resonant surface mode to be emitted into the far-field. Our study demonstrates a new approach to manipulate thermal radiation that could find applications in thermal management.