Open AccessAlmost-total absorption of light in thin, biperiodic, weakly-absorbing semiconductor gratings
Author(s) -
Evgeny Popov,
Anne-Laure Fehrembach,
R. C. McPhedran
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.016410
Subject(s) - absorptance , optics , materials science , absorption (acoustics) , grating , semiconductor , wavelength , dielectric , layer (electronics) , optoelectronics , attenuation coefficient , physics , reflectivity , composite material
We consider the design of optical systems capable of providing near 100% absorption of visible light, consisting of a structured thin layer of a weakly absorbing semiconductor placed on top of a dielectric spacer layer and a metallic mirror layer. We generalise a system recently studied semi-analytically and experimentally by Stürmberg et al [Optica 3, 556 2016] which incorporated a grating layer of antimony sulphide and delivered high, narrow-band absorptance of normally-incident light for a single polarisation. We demonstrate that bi-periodic gratings can be optimised to deliver near-perfect absorptance of unpolarised light in the system, and comment on the wavelength and angular ranges over which the absorptance remains near 100%. We show that the properties of the systems studied depend on the interaction of multiple modes, and cannot be accurately modelled within the quasistatic approximation.