Realizing Narrow Band Thermal Emitters in the Mid-Infrared by Utilizing Polaritonic Metasurfaces.*

The purpose of this study is to show evidence that surface phonon polaritonic(SPhP) metasurfaces can produce a well-defined thermal emission signal in the optical phonon band of Silicon Carbide to realize narrow band emitters in the mid-IR wavelengths. Preliminary data and results have demonstrated strong localized SPhP resonances of these devices, so there is a high possibility that a well-defined emission signal will be obtained if we apply Kirchhoff’s Law of Heat Radiation. To observe the thermal radiation from the polaritonic metasurface patterns, an optical setup was built in which the beam path of the visible light and thermal radiation would be equivalent. This was done primarily for the precise alignment of the metasurface and to maximize the collection of thermal radiation. The device was heated conventionally and data analysis was attained using a FTIR Spectrometer. Initial results showed an emission spectrum with broad resonances from 820 cm-1 to 960 cm-1 and it was determined the resonances were from multiple patterns on the metasurface. Currently, we have improved the setup to collect emissions from single patterns.