TY - JOUR

T1 - Study of dispersion of the evaporated gold permittivity in terahertz range based on characteristics of surface plasmon polaritons

AU - Gerasimov, V. V.

AU - Vanda, V. S.

AU - Lemzyakov, A. G.

AU - Kocheneva, A. G.

AU - Nazmov, V. P.

AU - Azarov, I. A.

AU - Kuznetsova, L. S.

AU - Ivanov, A. I.

AU - Nikitin, A.

N1 - The work was carried out at the shared research facility Siberian Center for Synchrotron and Terahertz Radiation on the basis of the Novosibirsk Free Electron Laser at Budker Institute of Nuclear Physics SB RAS. The authors thank the core facilities VTAN (Novosibirsk State University) for the access to the experimental equipment. The authors also thank the Novosibirsk free electron laser team for assistance in conducting the experiments, as well as I.G. Sokolova for proofreading the English text of this article.

PY - 2025

Y1 - 2025

N2 - The article presents results on determination of the effective dielectric permittivity ε1 of sputtered gold in the wavelength range λ = 51–357 μm (0.84–6 THz) from such surface plasmon polaritons (SPPs) characteristics as the refractive index and propagation length. The SPPs were generated on 15-cm flat samples containing a 0.8-µm magnetron-sputtered gold layer by radiation of the Novosibirsk free-electron laser. For suppression of radiative losses of SPPs, which deteriorate the measurement correctness, the gold surface was covered with a zinc sulfide layer of submicron thickness, at which the ohmic losses of SPPs significantly exceed the radiative losses. The SPP characteristics were measured with the surface plasmon Michelson interferometer, which gives considerably more reliable results than those gained by other conventional techniques. The obtained dependence ε1λ qualitatively correlates with calculations engaging the Drude model and reference data for the bulk metal with ideally smooth surface, but the found ε1 values are an order of magnitude less than the calculated ones, and an order of magnitude higher than all earlier-published data obtained found from experiments with SPPs.

AB - The article presents results on determination of the effective dielectric permittivity ε1 of sputtered gold in the wavelength range λ = 51–357 μm (0.84–6 THz) from such surface plasmon polaritons (SPPs) characteristics as the refractive index and propagation length. The SPPs were generated on 15-cm flat samples containing a 0.8-µm magnetron-sputtered gold layer by radiation of the Novosibirsk free-electron laser. For suppression of radiative losses of SPPs, which deteriorate the measurement correctness, the gold surface was covered with a zinc sulfide layer of submicron thickness, at which the ohmic losses of SPPs significantly exceed the radiative losses. The SPP characteristics were measured with the surface plasmon Michelson interferometer, which gives considerably more reliable results than those gained by other conventional techniques. The obtained dependence ε1λ qualitatively correlates with calculations engaging the Drude model and reference data for the bulk metal with ideally smooth surface, but the found ε1 values are an order of magnitude less than the calculated ones, and an order of magnitude higher than all earlier-published data obtained found from experiments with SPPs.

KW - Effective dielectric permittivity

KW - Metal layers

KW - Skin layer

KW - Surface plasmon polaritons

KW - Terahertz spectral range

KW - Thin dielectric layers

UR - https://www.scopus.com/pages/publications/105011970327

UR - https://www.mendeley.com/catalogue/51cc7db8-1cb3-326d-9a0d-56eb6bd833f4/

U2 - 10.1016/j.infrared.2025.106046

DO - 10.1016/j.infrared.2025.106046

M3 - Article

VL - 150

JO - Infrared Physics and Technology

JF - Infrared Physics and Technology

SN - 1350-4495

M1 - 106046

ER -