Design and deposition of a metal-like and admittance-matching metamaterial as an ultra-thin perfect absorber

Abstract

A stratiform metamaterial, comprising metal and dielectric thin films, exhibits both near-perfect antireflection and strong light extinction to function as a perfect and ultra-thin light absorber. The equivalent admittance and extinction coefficient of the metamaterial are tailored using a visual method that is based on an admittance diagram. A five-layered metamaterial was designed and deposited with a total thickness of 260 nm on a mirror to exhibit strong and wide angle absorption over wavelengths from 400 nm to 2000 nm. A seven-layered metamaterial with a total thickness of less than 200 nm was designed and deposited to have equivalent admittance around unity and an extinction coefficient that is comparable to that of metal. Such a metal-like metamaterial exhibits low reflectivity so couples most visible light energy into the films and dissipates energy with an equivalent skin depth of less than 55 nm over visible wavelengths.

Design a Stratiform Metamaterial with Precise Optical Property

“…In a previous work, a 7-layered metal-dielectric symmetrical film stack was designed and fabricated to have an E eq near unity and an N eq with large imaginary part that was comparable to that of a metal. Such a layered metamaterial can couple most incident light into the upper interface and dissipate its energy with a very small thickness [18].…”

Design and realization of light absorbers using plasmonic nanoparticles

“…A first highly-efficient absorber design concerns the metal-insulator-metal (MIM) structures [1][2][3]. The simplest MIM structure is composed of two metallic layers separated by a dielectric layer.…”

“…Deposition techniques such as sputtering [3] or thermal evaporation, sol-gel/spin coating [1] or Langmuir-Blodgett [5] methods, are of particular interest because of their simplicity and potential for low cost upscaling. Recent works have reported their ability to achieve efficient absorbers for large angles of incidence with a low polarization sensitivity.…”

High-efficiency and ultrabroadband flexible absorbers based on transversely symmetrical multi-layer structures

“…From the comparison results of admittance loci at different wavelengths, MIM resonance structure has the largest effective admittance, and it is noteworthy that the contribution of effective admittance of Cr in a short-wave band is much higher than that in a long-wave band. 37 Previous descriptions of this work focus on the effects of TM waves on the proposed absorber. Next, we also simulated the angular-dependence absorption spectra for TE and TM polarization waves, as shown in Figs.…”