Spectral emissivity design using aluminum-based hybrid gratings.

We propose a strategy to design infrared emitters with predefined spectral response using aluminum gratings as building blocks. We begin by identifying 3 target spectra with resonances in the 7-15 µm wavelength range. Next, we use FDTD simulations and interpolation to create a reference library of gratings relating their structural parameters to attributes of their infrared spectra. By using a search algorithm based on minimization of errors in spectral attributes, we identify gratings from this library corresponding to peaks in the target spectra. Finally, we discuss an approach for designing hybrid structures from these gratings to generate each of the 3 target spectra. This strategy can be extended to design structures with complex spectral responses.