title: Observation of continuous-wave on-resonance "self-focusing".
abstract: We report what to our knowledge are the first observations of an increase in the on-axis intensity of an intense cw on-resonance beam resulting from nonlinear absorption and diffraction during its propagation through a highly absorbing medium (sodium vapor). This "self-focusing" is not a self-lensing; instead it is modeled well by placing an aperture part way through the cell: The stripping by the aperture approximates the effect of the nonlinear absorption, and then Fresnel diffraction results in on-axis minima and maxima.
authors.forename: K
authors.initials: K
authors.lastname: Tai
authors.forename: H M
authors.initials: HM
authors.lastname: Gibbs
authors.forename: M C
authors.initials: MC
authors.lastname: Rushford
authors.forename: N
authors.initials: N
authors.lastname: Peyghambarian
authors.forename: J S
authors.initials: JS
authors.lastname: Satchell
authors.forename: M G
authors.initials: MG
authors.lastname: Boshier
authors.forename: R J
authors.initials: RJ
authors.lastname: Ballagh
authors.forename: W J
authors.initials: WJ
authors.lastname: Sandle
authors.forename: M
authors.initials: M
authors.lastname: Leberre
authors.forename: E
authors.initials: E
authors.lastname: Ressayre
authors.forename: A
authors.initials: A
authors.lastname: Tallet
authors.forename: J
authors.initials: J
authors.lastname: Teichmann
authors.forename: Y
authors.initials: Y
authors.lastname: Claude
authors.forename: F P
authors.initials: FP
authors.lastname: Mattar
authors.forename: P D
authors.initials: PD
authors.lastname: Drummond