Extraordinarily transparent compact metallic metamaterials

Samuel J. Palmer, Xiaofei Xiao, Nicolas Pazos-Perez, Luca Guerrini, Miguel A. Correa-Duarte, Stefan A. Maier, Richard V. Craster, Ramon A. Alvarez-Puebla, Vincenzo Giannini

Research output: Contribution to journalArticleResearchpeer-review

22 Citations (Scopus)

Abstract

The design of achromatic optical components requires materials with high transparency and low dispersion. We show that although metals are highly opaque, densely packed arrays of metallic nanoparticles can be more transparent to infrared radiation than dielectrics such as germanium, even when the arrays are over 75% metal by volume. Such arrays form effective dielectrics that are virtually dispersion-free over ultra-broadband ranges of wavelengths from microns up to millimeters or more. Furthermore, the local refractive indices may be tuned by altering the size, shape, and spacing of the nanoparticles, allowing the design of gradient-index lenses that guide and focus light on the microscale. The electric field is also strongly concentrated in the gaps between the metallic nanoparticles, and the simultaneous focusing and squeezing of the electric field produces strong ‘doubly-enhanced’ hotspots which could boost measurements made using infrared spectroscopy and other non-linear processes over a broad range of frequencies.

Original languageEnglish
Article number2118
Number of pages7
JournalNature Communications
Volume10
Issue number1
DOIs
Publication statusPublished - 1 Dec 2019
Externally publishedYes

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