title: Laser beams: knotted threads of darkness.
abstract: Destructive interference may lead to complete cancellation when light waves travelling in different directions cross, and in three-dimensional space this occurs along lines that are vortices of electromagnetic energy flow. Here we confirm theoretical predictions by experimentally creating combinations of optical laser beams in which these dark threads form stable loops that are linked and knotted.
authors.affiliation: Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK. j.leach@physics.gla.ac.uk
authors.forename: Jonathan
authors.initials: J
authors.lastname: Leach
authors.forename: Mark R
authors.initials: MR
authors.lastname: Dennis
authors.forename: Johannes
authors.initials: J
authors.lastname: Courtial
authors.forename: Miles J
authors.initials: MJ
authors.lastname: Padgett