title: Optical vortex metrology based on the core structures of phase singularities in Laguerre-Gauss transform of a speckle pattern.
abstract: A new technique for displacement measurement is proposed that makes use of phase singularities in the complex signal generated by a Laguerre-Gauss filter operation applied to a speckle pattern. The core structures of phase singularities are used as unique fingerprints attached to the object surface, and the displacement is determined by tracing the movement of registered phase singularities with their correspondence being identified by the fingerprints. Experimental results for translational and rotational displacement measurements are presented that demonstrate large dynamic range and high spatial resolution of the proposed optical vortex metrology.
authors.affiliation: Laboratory for Information Photonics and Wave Signal Processing, Department of Information and Communication Engineering, The University of Electro-Communications, 1-5-1, Chofugaoka, Chofu, Tokyo 182-8585, Japan. weiwang@ice.uec.ac.jp
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Yokozeki
authors.forename: Reika
authors.initials: R
authors.lastname: Ishijima
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Takeda
authors.forename: Steen G
authors.initials: SG
authors.lastname: Hanson