title: Generation of radially polarized beam with a segmented spiral varying retarder.
abstract: We convert a linearly polarized Gaussian beam into a radially polarized doughnut beam with an eight-segment spirally varying retarder (SVR) at wavelength of 808 nm. The SVR is designed based on the linear birefringence of alpha-barium borate (alpha-BBO) crystal and fabricated using a dry etching process. Radially polarized light of high purity (> 96% at far-field distribution) was generated experimentally using the segmented SVR positioned between two quarter waveplates with orthogonal slow axes. The emergent polarization can be switched between radially and azimuthally polarized cylindrical vector beams with a pair of half-wave plates.
authors.affiliation: Temasek Laboratories, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553.
authors.forename: W J
authors.initials: WJ
authors.lastname: Lai
authors.forename: B C
authors.initials: BC
authors.lastname: Lim
authors.forename: P B
authors.initials: PB
authors.lastname: Phua
authors.forename: K S
authors.initials: KS
authors.lastname: Tiaw
authors.forename: H H
authors.initials: HH
authors.lastname: Teo
authors.forename: M H
authors.initials: MH
authors.lastname: Hong
mesh_terms: D001464:Barium / Q000737:chemistry*; D001718:Birefringence; D001895:Boron / Q000737:chemistry*; D003460:Crystallization; D004867:Equipment Design; D008027:Light; D015233:Models, Statistical; D016011:Normal Distribution; D055095:Optics and Photonics; D017785:Photons; D012031:Refractometry; D012825:Silicon
chemical_list: D001464:Barium; D001895:Boron; D012825:Silicon