Abstract

It has been experimentally shown that a rigid polyimide Kapton film of submillimeter thickness is sufficiently transparent in the frequency range of 1.2–3 THz and can be used for splitting surface plasmon polaritons (SPPs) propagating along a flat conducting surface. The transmittance $T$ and reflectance $R$ measured for SPPs excited by a free-electron laser radiation ($\lambda =130\;\unicode{x00B5}{\rm m}$) in “gold–ZnS layer–air” flat structures are in good agreement with the results of numerical simulations obtained using the rigorous coupled-wave analysis technique. Transmittance of the SPPs decreases slightly when the layer gets thicker. To minimize the SPP radiative losses emerging due to diffraction of the SPPs on the impedance discontinuity, the Kapton film should be placed normal to the guiding surface and brought in good contact with it (the gap must be less than $\lambda /2$). The performed experiments clearly demonstrated Kapton films to be very promising for SPP beam splitting in large-scale terahertz SPP devices.

© 2020 Optical Society of America

Propagation of terahertz surface plasmon polaritons around a convex metal–dielectric interface

B. A. Knyazev, V. V. Gerasimov, A. K. Nikitin, I. A. Azarov, and Yu. Yu. Choporova
J. Opt. Soc. Am. B 36(6) 1684-1689 (2019)

Surface plasmon polaritons launched using a terahertz free-electron laser: propagation along a gold–ZnS–air interface and decoupling to free waves at the surface edge

Vasily V. Gerasimov, Boris A. Knyazev, Igor A. Kotelnikov, Alexey K. Nikitin, Valery S. Cherkassky, Gennady N. Kulipanov, and Guerman N. Zhizhin
J. Opt. Soc. Am. B 30(8) 2182-2190 (2013)

Excitation of terahertz surface plasmon polaritons on etched groove gratings

Michael Martl, Juraj Darmo, Karl Unterrainer, and Erich Gornik
J. Opt. Soc. Am. B 26(3) 554-558 (2009)

Terahertz spoof surface-plasmon-polariton subwavelength waveguide

Ying Zhang, Yuehong Xu, Chunxiu Tian, Quan Xu, Xueqian Zhang, Yanfeng Li, Xixiang Zhang, Jiaguang Han, and Weili Zhang
Photon. Res. 6(1) 18-23 (2018)

Multiple surface-plasmon-polariton waves guided by a chiral sculptured thin film grown on a metallic grating

Sema Erten, Muhammad Faryad, and Akhlesh Lakhtakia
J. Opt. Soc. Am. B 34(9) 1937-1945 (2017)