Labyrinthine patterns on an inhomogeneous background in a nonlinear optical system

We experimentally show the existence of labyrinthine patterns between spatially modulated steady states in a simple nonlinear optical system consisting of a sodium vapor cell and a single feedback mirror. The inhomogeneity of the steady states leads to a locking phenomenon determining the length scale of the labyrinthine patterns and diminishes their region of existence in favor of localized periodic patterns. Numerical simulations confirm the experimental observations.