title: Optical pattern transitions from modulation to transverse instabilities in photorefractive crystals.
abstract: We show by experimental measurements and theoretical analyses that there exists a pattern transition from optical modulation instability to transverse instability in nonlinear media. An input coherent beam propagating in the photorefractive crystals is observed to break up into stripe filaments at a first threshold voltage. By modeling the periodic strip filaments as cnoidal waves, we demonstrate that a second threshold voltage for forming dot filaments comes from the transverse instability, resulting in a good agreement with the experimental data.
authors.affiliation: Department of Physics, National Chung-Hsing University, Taichung 402, Taiwan.
authors.forename: Chien-Chung
authors.initials: CC
authors.lastname: Jeng
authors.forename: YuanYao
authors.initials: Y
authors.lastname: Lin
authors.forename: Ray-Ching
authors.initials: RC
authors.lastname: Hong
authors.forename: Ray-Kuang
authors.initials: RK
authors.lastname: Lee