title: Broadband perfect absorber based on one ultrathin layer of refractory metal.
abstract: Broadband perfect absorber based on one ultrathin layer of the refractory metal chromium without structure patterning is proposed and demonstrated. The ideal permittivity of the metal layer for achieving broadband perfect absorption is derived based on the impedance transformation method. Since the permittivity of the refractory metal chromium matches this ideal permittivity well in the visible and near-infrared range, a silica-chromium-silica three-layer absorber is fabricated to demonstrate the broadband perfect absorption. The experimental results under normal incidence show that the absorption is above 90% over the wavelength range of 0.4-1.4 μm, and the measurements under angled incidence within 400-800 nm prove that the absorber is angle-insensitive and polarization-independent.
authors.forename: Huixu
authors.initials: H
authors.lastname: Deng
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Li
authors.forename: Liliana
authors.initials: L
authors.lastname: Stan
authors.forename: Daniel
authors.initials: D
authors.lastname: Rosenmann
authors.forename: David
authors.initials: D
authors.lastname: Czaplewski
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Yang