title: Focusing of higher-order radially polarized Laguerre-Gaussian beam.
abstract: We consider the formation of a small focal spot, which has been reported in [J. Opt. Soc. Am. A 24, 1793 (2007)], by separating a higher-order radially polarized Laguerre-Gaussian beam into two parts: a Bessel-like multi-ring part and an annular part. The latter forms a dominant small spot of longitudinal electric field component near the focus, while the former mainly contributes to a weak annular pattern of radial component.
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan. kozawa@tagen.tohoku.ac.jp
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kozawa
authors.forename: Shunichi
authors.initials: S
authors.lastname: Sato