title: Propagation characteristics of a focused laser beam in a strontium barium niobate photorefractive crystal under reverse external electric field.
abstract: The propagation characteristics of a focused laser beam in a SBN:75 photorefractive crystal strongly depend on the signal-to-background intensity ratio (R=Is/Ib) under reverse external electric field. In the range 20>R>0.05, the laser beam shows enhanced self-defocusing behavior with increasing external electric field, while it shows self-focusing in the range 0.03>R>0.01. Spatial solitons are observed under a suitable reverse external electric field for R=0.025. A theoretical model is proposed to explain the experimental observations, which suggest a new type of soliton formation due to "enhancement" not "screening" of the external electrical field.
authors.forename: Q L
authors.initials: QL
authors.lastname: Guo
authors.forename: B L
authors.initials: BL
authors.lastname: Liang
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: G Y
authors.initials: GY
authors.lastname: Deng
authors.forename: Y H
authors.initials: YH
authors.lastname: Jiang
authors.forename: S H
authors.initials: SH
authors.lastname: Zhang
authors.forename: G S
authors.initials: GS
authors.lastname: Fu
authors.forename: P J
authors.initials: PJ
authors.lastname: Simmonds
mesh_terms: D001464:Barium / Q000737:chemistry* / Q000528:radiation effects; D003460:Crystallization; D007834:Lasers; D008422:Materials Testing; D009556:Niobium / Q000737:chemistry* / Q000528:radiation effects; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation; D013324:Strontium / Q000737:chemistry* / Q000528:radiation effects
chemical_list: D009556:Niobium; D001464:Barium; D013324:Strontium