Abstract

We consider a self-defocusing model for a Kerr medium in a planar resonator, which takes into account the vectorial character of the radiation field For an intensity of the pump beam larger than a given threshold, a y polarized transverse stripe pattern appears. We analyze the spatial behavior of quantum fluctuations around this inhomogeneous steady state, using a Langevin treatment based on Wigner representation. The model is continuous, so that we avoid any restriction to a reduced number of spatial modes The spatial distribution of the quantum fluctuations around the roll-pattern is dominated by the neutral (or Goldstone) mode, corresponding to rigid spatial displacements of the pattern The spatial configuration of the field immediately outside the cavity input/output mirror depends on the time window over which fluctuations are averaged: only when the time window is on the order of the cavity lifetime the output field fluctuations are qualitatively similar to that of the intracavity field. In Fig.1 we compare fluctuations inside a) and outside the cavity b) in the y-polarized field.

© 2000 IEEE