Instabilities, Self-Oscillation, and Chaos in a Simple Nonlinear Optical Interaction

It is shown that two light beams interacting in a third-order nonlinear medium undergo transition from a stationary to periodic and chaotic states, as their intensities are increased. A threshold for the onset of instabilities is calculated and verified by computer simulations. It is therefore proved that external feedback is not necessary for self-oscillations in nonlinear optical systems.