title: Overcoming the impeding effect of core-cladding interface on the progression of the second-order nonlinearity in thermally poled optical fibers.
abstract: The spatial distribution of the second-order optical nonlinearity in thermally poled optical fibers was characterized with second-harmonic microscopy. The second-order optical nonlinearity (SON) was found to be distributed in a layer, the progression of which was impeded at the core-cladding interface, which acted as an extra potential barrier to the migrating ions. At higher poling voltages and temperatures, the SON layer could overcome this barrier and extend further into the fiber core. The polarization dependence of the optical nonlinearity within the fiber core was also checked and found to be almost negligible.
authors.affiliation: Optical Fibre Technology Cente, Australian Photonics Cooperative Research Centre, University of Sydney, 206 National Innovation Centre, Australian Technology Park, Eveleigh, NSW 1430, Australia. h.an@oftc.usyd.edu.au
authors.forename: Honglin
authors.initials: H
authors.lastname: An
authors.forename: Simon
authors.initials: S
authors.lastname: Fleming