Fundamental scaling laws of on-off intermittency in a stochastically driven dissipative pattern-forming system

Noise-driven electroconvection in sandwich cells of nematic liquid crystals exhibits on-off intermittent behavior at the onset of the instability. We study laser scattering of convection rolls to characterize the wavelengths and trajectories of the stochastic amplitudes of the intermittent structures. The pattern wavelengths and statistics of these trajectories are in quantitative agreement with simulations of the linearized electrohydrodynamic equations. The fundamental tau(-3/2) distribution law for the durations tau of laminar phases as well as the power law of the amplitude distribution of intermittent bursts are confirmed in the experiments. Power spectral densities of the experimental and numerically simulated trajectories are discussed.