title: Vectorial vortex mode transformation for a hollow waveguide using Pancharatnam-Berry phase optical elements.
abstract: Transformation and inverse transformation between a free-space linearly polarized beam and the vectorial vortex mode of a circular hollow waveguide by use of Pancharatnam-Berry phase optical elements is proposed. Demonstration was achieved by fabricating GaAs subwavelength gratings and utilizing a 300 microm diameter hollow metallic waveguide for 10.6 microm wavelength CO(2) laser radiation. The mode transformations and the excitation of a single vectorial mode inside the hollow waveguide were verified by full polarization measurements. In addition, the inverse mode transformation of the single vectorial mode excitation in the waveguide enabled us to experimentally obtain a linearly polarized bright spot with a high central lobe.
authors.affiliation: Optical Engineering Laboratory, Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Yirmiyahu
authors.forename: Avi
authors.initials: A
authors.lastname: Niv
authors.forename: Gabriel
authors.initials: G
authors.lastname: Biener
authors.forename: Vladimir
authors.initials: V
authors.lastname: Kleiner
authors.forename: Erez
authors.initials: E
authors.lastname: Hasman