Noise-sustained convective structures in nonlinear optics

Evidence of the existence of noise-sustained patterns in
nonlinear optical systems is given. They are found in passive
optical cavities, filled by Kerr type nonlinear media, when
the angle of incidence of the pump beam is not zero, in a
regime of convective instability. These patterns arise as a
macroscopic manifestation of amplified noise. We characterize
the difference between noise-sustained and deterministic
patterns in terms of statistical properties of the field
spectral intensity.