title: Circular grating coupler for creating focused azimuthally and radially polarized beams.
abstract: We show a planar optical circuit design that takes light from an input waveguide and creates a focused azimuthally or radially polarized beam emanating from the surface of the substrate. It is implemented in silicon-on-insulator waveguides and does not require any external components to focus the beam. The focal spot size can be subwavelength and is potentially useful for lithography, imaging, optical data storage, optical trapping, optical excitation of molecules, or coupling to optical fibers.
authors.affiliation: Bell Laboratories, Alcatel-Lucent, 791 Holmdel Road, Holmdel, New Jersey 07733, USA. crdoerr@alcatel-lucent.com
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Doerr
authors.forename: Lawrence L
authors.initials: LL
authors.lastname: Buhl