This research program will study control of the chaotic dynamics of solid state laser systems that contain intracavity nonlinear elements. These laser systems are rapidly finding important applications in optical communications and information processing, materials processing, medicine and laser radar. Specific goals include novel pulsed operation and complex periodic waveform generation by semiconductor and diode-pumped solid state lasers. These goals will be achieved through the development of control techniques that are applicable to chaotic systems. Control algorithms that have very recently been developed by Ott, Grebogi and Yorke will be implemented on laser systems to obtain specific complex waveforms that cannot be generated by stable systems. This will require novel electronic and optical techniques for fast feedback and control of laser parameters. We will attempt to control multimode laser systems and develop the techniques for switching between complex periodic waveforms, such as the antiphase states demonstrated recently in a diode-pumped solid state laser. Such studies should have an impact not only on the development of new laser systems and optical communications, but on the control of systems of chemical reactions and biological systems as well. A fundamental understanding of the statistical nature of chaotic dynamics and the influence of quantum noise in chaotic lasers will be developed.