Kavli Affiliate: Anna V. Shneidman
| First 5 Authors: Alireza Shahsafi, Graham Joe, Soeren Brandt, Anna V. Shneidman, Nicholas Stanisic
| Summary:
Engineered optical absorbers are of substantial interest for applications
ranging from stray light reduction to energy conversion. We demonstrate a
large-area (centimeter-scale) metamaterial that features near-unity
frequency-selective absorption in the mid-infrared wavelength range. The
metamaterial comprises a self-assembled porous structure known as an inverse
opal, here made of silica. The structure’s large volume fraction of voids,
together with the vibrational resonances of silica in the mid-infrared spectral
range, reduce the metamaterial’s refractive index to close to that of air and
introduce considerable optical absorption. As a result, the frequency-selective
structure efficiently absorbs incident light of both polarizations even at very
oblique incidence angles. The absorber remains stable at high temperatures
(measured up to ~900 degrees C), enabling its operation as a
frequency-selective thermal emitter. The excellent performance of this
absorber/emitter and ease of fabrication make it a promising surface coating
for passive radiative cooling, laser safety, and other large-area applications.
| Search Query: ArXiv Query: search_query=au:”Anna V. Shneidman”&id_list=&start=0&max_results=3