Abstract

Spontaneous pattern formation has been widely studied both by experimentalists and theoreticians. But most of these studies have concentrated on optical systems having third- order nonlinearities. Second order nonlinear effects have recently received a large interest. They provide at the same time a simple mechanism and a rich variety of phenomena because of the coupling between waves of different frequencies. Theoreticians have predicted various transverse patterns especially in the case of Optical Parametric Oscillators (OPO) [1]. We have developed a c.w. OPO operating in cavities with degenerate transverse modes and observed spontaneous pattern formation due to second order nonlinearity [2].

© 2000 IEEE