Compact photonic-crystal superabsorbers from strongly absorbing media
Devarapu, Ganga Chinna Rao
Journal of Applied Physics
American Institute of Physics (AIP)
We present a route to near-perfect absorption in compact photonic-crystal (PC) structures constructed from strongly absorbing media that are typically highly reflective in bulk form. Our analysis suggests that the key underlying mechanism in such PC superabsorbers is the existence of a PC-band-edge reflectionless condition. Although the latter is by default uncharacteristic in photonic crystals, we propose here a clear recipe on how such condition can be met by tuning the structural characteristics of one-dimensional lossy PC structures. Based on this recipe, we constructed a realizable three-layer SiC- BaF2 -SiC PC operating within the Reststrahlen band of SiC. We demonstrate near-perfect absorption in this prototype of total thickness smaller than λ/3 , where more than 90% of the impinging light is absorbed by the top deep-subwavelength layer of thickness ∼λ/1100 . We believe our study will inspire new photonic-crystal-based designs for extreme absorption harnessing across the electromagnetic spectrum.
University of Exeter
Copyright © 2013 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Journal of Applied Physics, Volume 114 (3), article 033504, and may be found at http://dx.doi.org/10.1063/1.4811521
Vol. 114 (3), article 033504