Thermal Photonics: Spectral, Directional and Nonreciprocal Control of Thermal Light Emission

Thermal management is a central challenge facing next-generation microelectronic technologies. from the chip-scale to the data center level. In this context, controlling and leveraging light emission through passive or active means remains a comparatively underexplored and understudied approach. In this talk, I will introduce our work on thermal photonics, including strategies to control the spectral and directional characteristics of thermal emission over infrared wavelengths, as well as violating the principle of detailed balance. 

First, I will show how a heavily-doped III-V-material-based platform allows us to enable tunable frequency and angle selectivity in emission across both polarizations by harnessing Epsilon-near-zero and effective Mu-near-zero behavior these systems can be engineered to support. Furthermore, I will show how Kirchhoff's law of thermal radiation can be violated over broad wavelengths by breaking Lorentz reciprocity in nonreciprocal photonic systems, enabling new capabilities for radiative heat transfer. I will highlight how new theoretical formalisms can allow us to probe the fundamental limits of magneto-optic control of nonreciprocity, and that experimentally we can now achieve broad spectrum nonreciprocal thermal emission.

Finally, one application of these capabilities, I will summarize our group's recent work on radiative cooling technologies for passive, non-evaporative cooling and its use for a broad range of energy applications.