title: Self-focusing in photorefractive two-wave mixing.
abstract: Self-focusing and self-defocusing of light in two-wave mixing are investigated experimentally. Amplification and self-focusing are measured as functions of the frequency shift between signal and pump beams. A frequency dependence is found in Kramers-Kronig form, as is plausible by the analogy of photorefractive amplification and laser amplification. Reversal of the external dc field on the material or a change in the frequency shift between the signal and pump beams is found to change self-focusing to self-defocusing.
authors.forename: M
authors.initials: M
authors.lastname: Vaupel
authors.forename: C
authors.initials: C
authors.lastname: Seror
authors.forename: R
authors.initials: R
authors.lastname: Dykstra