Nonlinear pattern formation in active optical systems: Shocks, domains of tilted waves, and cross-roll patterns

Vortices, shocks, domains of tilted waves, and cross-roll patterns are typical patterns of the complex Swift-Hohenberg equation, which describes spatiotemporal dynamics in nonlinear optical systems of large Fresnel number, such as lasers, optical parametric oscillators, and photorefractive oscillators. We show the occurrence of such ''essentially nonlinear'' patterns experimentally on a photorefractive oscillator and compare it with numerical solutions of the complex Swift-Hohenberg equation.