ELIMINATION OF SPATIOTEMPORAL DISORDER BY FOURIER SPACE TECHNIQUES

A recently proposed method for the stabilization of unstable patterns uses an instantaneous feedback derived from the Fourier transform of t he output [R. Martin et al., Phys. Rev. Leu. 66, 4007 (1996)]. We succ essfully extend this method to regimes of spatiotemporal disorder. By focusing on two different nonlinear optical systems, a laser and a Ker r slice with feedback, we demonstrate the usefulness, effectiveness, a nd generality of the technique. Our method allows for high power outpu ts without loss of spatial and temporal coherence. It also provides th e possibility of pattern selection and, in some instances, tracking wi thin a disordered regime.