title: Determination of the polarization states of an arbitrary polarized terahertz beam: vectorial vortex analysis.
abstract: Vectorial vortex analysis is used to determine the polarization states of an arbitrarily polarized terahertz (0.1-1.6 THz) beam using THz achromatic axially symmetric wave (TAS) plates, which have a phase retardance of Δ = 163° and are made of polytetrafluorethylene. Polarized THz beams are converted into THz vectorial vortex beams with no spatial or wavelength dispersion, and the unknown polarization states of the incident THz beams are reconstructed. The polarization determination is also demonstrated at frequencies of 0.16 and 0.36 THz. The results obtained by solving the inverse source problem agree with the values used in the experiments. This vectorial vortex analysis enables a determination of the polarization states of the incident THz beam from the THz image. The polarization states of the beams are estimated after they pass through the TAS plates. The results validate this new approach to polarization detection for intense THz sources. It could find application in such cutting edge areas of physics as nonlinear THz photonics and plasmon excitation, because TAS plates not only instantaneously elucidate the polarization of an enclosed THz beam but can also passively control THz vectorial vortex beams.
authors: School of Biomedical Engineering, Saitama Medical University, Yamane 1397-1, Hidaka, Saitama 350-1241, Japan.
authors: Toshitaka
authors: T
authors: Wakayama
authors: 1] Department of Advanced Interdisciplinary Sciences, Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585, Japan [2] Center for Optical Research &Education (CORE), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585, Japan.
authors: Takeshi
authors: T
authors: Higashiguchi
authors: Department of Advanced Interdisciplinary Sciences, Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585, Japan.
authors: Hiroki
authors: H
authors: Oikawa
authors: Research Institute for Science and Engineering, Waseda University, Kikuicho 17, Shinjuku, Tokyo 162-0044, Japan.
authors: Kazuyuki
authors: K
authors: Sakaue
authors: Research Institute for Science and Engineering, Waseda University, Kikuicho 17, Shinjuku, Tokyo 162-0044, Japan.
authors: Masakazu
authors: M
authors: Washio
authors: School of Biomedical Engineering, Saitama Medical University, Yamane 1397-1, Hidaka, Saitama 350-1241, Japan.
authors: Motoki
authors: M
authors: Yonemura
authors: NPO 3D Associates, Kishiya 4-13-18, Yokohama, Japan.
authors: Toru
authors: T
authors: Yoshizawa
authors: College of Optical Sciences, The University of Arizona, Tucson, AZ 85721, USA.
authors: J Scott
authors: JS
authors: Tyo
authors: Center for Optical Research &Education (CORE), Utsunomiya University, Yoto 7-1-2, Utsunomiya, Tochigi 321-8585, Japan.
authors: Yukitoshi
authors: Y
authors: Otani