title: Third-order nonlinear spectra and optical limiting of lead oxifluoroborate glasses.
abstract: We have determined two-photon absorption and nonlinear refraction spectra of the 50BO(1.5) - (50-x)PbF(2) - xPbO glasses (with x = 25, 35, 50 cationic %) at the range of the 470 and 1550 nm. The replacement of fluor atoms by oxygen leads to an increase in the third-order susceptibility, due to the formation of non-bridging oxygens (NBO). The nonlinear index of refraction is one order of magnitude higher than the one for fused silica, and it increases almost twice for the sample with x = 50. This sample has also shown promising features for all-optical switching as well as for optical limiting.
authors.affiliation: Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, Brasil.
authors.forename: J M P
authors.initials: JM
authors.lastname: Almeida
authors.forename: L
authors.initials: L
authors.lastname: De Boni
authors.forename: A C
authors.initials: AC
authors.lastname: Hernandes
authors.forename: C R
authors.initials: CR
authors.lastname: Mendonça