Pattern Formation in Non-Linear Optics Ana Jofre Transverse spatial structures comprised of patterns such as hexagons, rings, and stripes are frequently observed in laser beams traversing nonlinear optical media. Three typical systems in which such pattern formation occurs are a Fabry-Perot Cavity containing a non-linear medium, a non-linear medium interacting with counterpropagating beams, and a thin non-linear medium with a single feedback mirror. The observed pattern depends on the polarization of the beam, the non-linear medium, and parameters of the experimental set-up such as the distance between the feedback mirror and the non-linear medium. An overview of the mechanism involved leading to pattern formation and the corresponding experimental observations will be presented. --------------E67C10EB8055F152FBB1B84A--