Photorefractive Nonlinear Optics.

Abstract

Abstract : This research program resulted in the development of several new photorefractive devices, and an increase in basic understanding of photorefractive nonlinear interactions. We developed an interferometric phase conjugating ellipsometer which also led to a new highly accurate class of interferometer applicable to polarimetry and distance measurement. The effectiveness of photorefractive beam cleanup was investigated, and found to be most useful for highly aberrated beams. We investigated the feasibility of efficient self aligning coupling of multiple beams simultaneously into a single single mode fiber. This has applications to fiber optic communications. We studied methods of broadening the spectral bandwidth of volume holographic devices by using achromatic techniques. Applications are in self-pumped phase conjugation of trains of femtosecond pulses, and high data rate transmission in optical fibers. The photorefractive beam propagation method was developed as a tool to analyze photorefractive devices and effects involving large bandwidth signals. It was also applied to model amplified photorefractive scattering (fanning) and the double phase conjugate mirror. A successful statistical model of fanning was developed and tested. We have also begun to study photorefractive waveguides, both epitaxially grown and self induced. High resolution X-ray topography was used to investigate photorefractive crystals and waveguides. A new method for nonvolatile data storage in photorefractive crystals was discovered and theoretically analyzed. (MM)