Thermal Radiation from Nanophotonic Structures: Theory, Numerical Simulation and Applications

Thermal radiation manifests a ubiquitous aspect of nature. Any object with a finite temperature emits thermal radiation due to the thermally induced motion of charged particles or quasiparticles. The blackbody radiation model put forward by Max Planck sets the limit for the thermal radiation in terms of intensity and directionality. The ability to manipulate thermal radiation to achieve desired radiative properties lays the foundation for many promising applications such as radiative cooling, infrared sensing and thermophotovoltaic device. Nanophotonic structures prove to be the ideal platform to control thermal radiation. However, the understanding of the thermal radiation from nanophotonic structures is still relatively immature in the aspects of numerical modeling, theoretical description and experimental demonstrations and characterization.

In this dissertation, we systematically investigate the thermal radiation from nanophotonic structures such as metamaterial, 2D materials, plasmonic emitters, etc. We develop and implement highly efficient numerical tools to directly calculate the thermal radiation from arbitrary geometries based on the fluctuational electrodynamics. With these numerical tools, we investigate the thermal radiation of complex nanophotonic structures, and propose a set of general theories to explain and predict the thermal radiation from nanophotonic structures. Finally, we demonstrate the spectral, directional and active control of the thermal radiation from nanophotonic structures verified through numerical simulation, theoretical prediction and experiments by using the nano-fabrication techniques. In addition, we also manage to extract near-field thermal radiation from nanostructures via optical waveguide.