Deeply Subwavelength Layered Metamaterials: From Hyperbolic Dispersion Metasurfaces to Fano Resonance Optical Coatings

Abstract

In recent years a wide interest has been spurred by the inverse design of artificial layered heterostructures for nano-biophotonic applications. In particular, the extreme optical properties of artificial hyperbolic dispersion nanomaterials allowed to access new physical effects and mechanisms. The unbound isofrequency surfaces of hyperbolic metamaterials and metasurfaces allow to access virtually infinite photonic density of states, ultrahigh confinement of electromagnetic fields and anomalous wave propagation. Similarly, by layering metal-dielectric thin films is possible to obtain a type of optical coatings that exhibit photonic Fano resonance, or a Fano-resonant optical coating (FROC). We expand the coupled mechanical oscillator description of Fano resonance to thin-film nanocavities. We observed that semi-transparent FROCs can transmit and reflect the same color as a beam splitter filter, a property that cannot be realized through conventional optical coatings. Here, we present the physics of different deeply subwavelength layered heterostructures and how they allow to control light-matter interaction at the single nanometer scale, including within living systems.REFERENCES[1] K. V. Sreekanth, Antonio De Luca & Giuseppe Strangi "Experimental demonstration of surface and bulk plasmon polaritons in hypergratings” Scientific Reports 3, 03291 (2013)[2] K. V. Sreekanth, Y. Alapan, M. ElKabbash, U. A. Gurkan, E. Ilker, M. Hinczevski, A. De Luca and G. Strangi Nature Materials 15, 4 4609 (2016)[3] ElKabbash, M., Letsou, T., Jalil, S.A. Hoffman N., Lininger A., Hinczewski M. et.al & G. Strangi. “Fano-resonant ultrathin film optical coatings”. Nature Nanotechnology (2021). https://doi.org/10.1038/s41565-020-00841-9