title: Measurement of submicrometre diameters of tapered optical fibres using harmonic generation.
abstract: Applications of subwavelength-diameter optical fibres in nonlinear optics require precise knowledge of the submicrometre fibre waist diameter. We demonstrate a new technique for optical measurement of the diameter based on second- and third-harmonic generation with an accuracy of better than 2%. To generate the harmonic light, inter-modal phase matching must be achieved. We find that the phase-matching condition allows us to unambiguously deduce the fibre diameter from the wavelength of the harmonic light. High-resolution scanning electron microscope imaging is used to verify the results.
authors.affiliation: Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn, Germany. wiedemann@iap.uni-bonn.de
authors.forename: Ulrich
authors.initials: U
authors.lastname: Wiedemann
authors.forename: Konstantin
authors.initials: K
authors.lastname: Karapetyan
authors.forename: Cristian
authors.initials: C
authors.lastname: Dan
authors.forename: Dimitri
authors.initials: D
authors.lastname: Pritzkau
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Alt
authors.forename: Stephan
authors.initials: S
authors.lastname: Irsen
authors.forename: Dieter
authors.initials: D
authors.lastname: Meschede