Convection induced nonlinear phase modulations in optical systems

This study presents convection induced nonlinear phase modulations in optical systems. This investigation considers a degenerate optical parametric oscillator (DOPO) because convection (walk-off) arises naturally from the crystal birefringence that composes the optical device. Near to the threshold the nonlinear symmetry breaking is described by a Ginzburg-Landau model with an original dependence of the nonlinear self-coupling term upon convection. As a result, nonlinear travelling waves are no more symmetrical and the explicit analytical expressions of their intensities ratio with both convection and the distance from threshold are derived. Results show good agreement between the analytical and numerical results for the intensities ratio of the travelling waves that compose the signal field.