Fourier space control in an LCLV feedback system

We show that a control technique, based on feedback filtered at a Fourier plane, can stabilize the spatio-temporally disordered output of a nonlinear optical system. We demonstrate this in an experiment with a LCLV feedback system and in a theoretical model. We stabilize the system and select square and roll patterns. The technique is non-invasive in that the control signal becomes small when control is achieved. A combination of real- and Fourier-space filtering can stabilize patterns in any chosen region of the transverse space.