Fundamental & Applications of Nonlinear Optics.

The report describes research on nonperturbative solutions to problems in resonant nonlinear optics and on photorefractive nonlinear optics and its applications. Nonperturbative solutions have been found for optical double resonance and applied to optical switching and three wave mixing in quantum well materials and to degenerate four wave mixing studies on the 2 Sigma - 2Pi 0-0 band of OH. A nonperturbative analysis has also been carried out for simultaneous one, two, and three photon resonances in coherent anti-Stokes Raman spectroscopy CARS. This allows optimization of CARS signals in diagnostic systems that operate at very low particle densities. Research has also been carried on periodically driven two level systems and two level systems with permanent dipole moments. In other work, the beam propagation method has been developed for use in photorefractive nonlinear optics. This method has been applied to the problem of nonlinear beam cleanup and to studies of the statistical nature of amplified scattering. Development was carried out on phase conjugate interferometry and ellipsometry measurement techniques for thin films. For holographic storage systems that use different wavelengths for reading and writing, a birefringent phase matching technique has also been developed.