Temporally and Spatially Coherent Emission from Thermal Embedded Eigenstates

Thermal emission manipulation is of key importance in numerous applications, yet a number of challenges have prevented its full technical maturation. Efficient mid- and far-infrared sources are valuable for sensing and thermal engineering, yet they are far from matching the sophistication of sources at lower or higher frequencies. Spectrally or spatially narrowband thermal emission has been proposed, partially overcoming the inherent incoherence of thermal processes. However, designing an ideal thermal source with spectral and spatial tailoring of the emission, and enhancing its line width within a small footprint, remains significantly challenging. Here we show how embedded eigenstates in the radiation continuum can be employed to realize compact thermal sources with narrow frequency and spatial spectra of emission, broadening the opportunities for thermal emission manipulation. The proposed concept can be extended to a wide class of thermal emitters, as well as more broadly within the context of thermal management.