O. Sandfuchs et al., SPATIOTEMPORAL PATTERN-FORMATION IN COUNTERPROPAGATING 2-WAVE MIXING WITH AN EXTERNALLY APPLIED-FIELD, Journal of the Optical Society of America. B, Optical physics, 15(7), 1998, pp. 2070-2078
The spatiotemporal dynamics of two counterpropagating beams in a photo
refractive crystal with nonlocal and sluggish response is investigated
in the longitudinal and one transverse dimension. A static external e
lectric field is applied to the crystal to control the coupling streng
th of the two-wave mixing process. A nonautonomous linear stability an
alysis is performed that takes a nonconstant modulation depth into acc
ount. The onset of pattern formation for arbitrary coupling constants
and pump ratios and the influence of linear absorption are discussed.
Above the threshold predicted by stability analysis, running transvers
e waves appear in the optical near field and wandering spots appear in
the corresponding far field. A nonlinear eigenmode analysis reveals t
he running transverse waves as secondary instabilities. (C) 1998 Optic
al Society of America.