title: Asymmetric transmission of radially polarized THz radiation through a double circular grating.
abstract: We report on unidirectional and asymmetric transmission of radially polarized THz radiation through a dual circular metallic grating with sub-wavelength slits. Unidirectional transmission is shown theoretically for a super-Gaussian incident beam, and an asymmetric transmission is demonstrated experimentally, when the radially polarized beam of 0.1 THz is obtained by converting a linearly polarized beam with a discontinuous phase retarder and a tapered waveguide. The dual grating does not include nonlinear materials, its operation is reciprocal, and analogous to that of some planar metallic gratings.
authors.forename: Dmitriy
authors.initials: D
authors.lastname: Yavorskiy
authors.forename: Marcin
authors.initials: M
authors.lastname: Stolarek
authors.forename: Jerzy
authors.initials: J
authors.lastname: Łusakowski
authors.forename: Rafał
authors.initials: R
authors.lastname: Kotyński