Permittivity evaluation of multilayered hyperbolic metamaterials: Ellipsometry vs. reflectometry
Abstract
Metal-dielectric nanolaminates represent a class of hyperbolic metamaterials with uniaxial permittivity tensor. In this study, we critically compare permittivity extraction of nanolaminate samples using two techniques: polarized reflectometry vs. spectroscopic anisotropic ellipsometry. Both Au/MgF2 and Ag/MgF2 metal-dielectric stacks are examined. We demonstrate the applicability of the treatment of the multilayered material as a uniaxial medium and compare the derived optical parameters to those expected from the effective medium approximation. We also experimentally compare the effect of varying the material outer layer on the homogenization of the composite. Additionally, we introduce a simple empirical method of extracting the epsilon-near-zero point of the nanolaminates from normal incidence reflectance. The results of this study are useful in accurate determination of the hyperbolic material permittivity and in the ability to tune its optical properties.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Mar 11, 2015
- Source ID
- 10.1063/1.4914524
Entities
People
- M. A. Noginov
- S. T. Kee
- T. U. Tumkur
- V. Liberman
- Y. Barnakov
Organizations
- Air Force Office of Scientific Research
- Army Research Office
- Massachusetts Institute of Technology
- National Science Foundation
- Norfolk State University