Almost-total absorption of light in thin, biperiodic, weakly-absorbing semiconductor gratings

作者：Popov Evgeny; Fehrembach Anne Laure; Mcphedran Ross C^*

来源：Optics Express, 2016, 24(15): 16410-16424.

DOI：10.1364/OE.24.016410

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 Stumberg 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.

• 出版日期2016-7-25