Demonstration of a nearly ideal wavelength-selective optical mirror using a metamaterial-enabled dielectric coating

Abstract

We report a thin nanostructured dielectric optical coating with a nearly ideal polarization insensitive reflectance at a wavelength of 3.46 μm. A genetic algorithm was used to optimize the doubly periodic amorphous silicon subwavelength nanostructure to satisfy a metamaterial-enabled reflecting condition at this resonance wavelength. Optical measurements of the nanofabricated dielectric coating had a peak reflectance of 99.76% at 3.46 μm, showing strong agreement with simulation. The average reflectance measured at nine positions on a 2.54 cm × 2.54 cm coating demonstrated a high optical uniformity of 99.5% ± 0.1% across the large-area component. These results outline a route to design and manufacture low-loss metamaterial-enabled dielectric optical coatings.