Abstract

We theoretically investigate the formation of spatio-temporal structures in photorefractive media with interaction through reflection gratings and a non-local and sluggish medium response as in BaTiO₃, for example. An external static electric field is applied across the crystal in order to control the coupling strength which then becomes complex and leads to the formation of a running grating. A linear stability analysis predicts the onset of pattern formation for a counterpropagating beam geometry [1]. The homogeneous fixed-point solution spontaneously becomes unstable against a transverse spatial modulation through a Hopf-bifurcation.

© 1998 IEEE