title: Generation of azimuthally polarized beams in fast axial flow CO2 laser with hybrid circular subwavelength grating mirror.
abstract: A hybrid circular subwavelength grating mirror is proposed and fabricated as a rear mirror in a fast axial flow CO2 laser system to generate azimuthally polarized beams (APBs). This grating mirror, with particular gold-covered ridges and nanopillar-stuffed grooves, performs wideband TE wave reflectivity and high polarization selectivity. It shows that the polarization selectivity mechanism lies in the gold ridge's high reflectivity to the TE wave and the lower TM wave reflectivity, which are the result of the mode leaking into substrate through the dielectric-like nanopillar layer. Finally, a high-quality 550 W APB is obtained in subsequent experiments, which provides potential applications in drilling and welding.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhao
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Heng
authors.initials: H
authors.lastname: Zhao
authors.forename: Wenjin
authors.initials: W
authors.lastname: Wang
authors.forename: Yi
authors.initials: Y
authors.lastname: Hu
authors.forename: Sisi
authors.initials: S
authors.lastname: Liu
authors.forename: Youqing
authors.initials: Y
authors.lastname: Wang