A new symposium is being arranged to take place April 27 - May 1, 1992 at the Spring Meeting of the Materials Research Society to be held in San Francisco. The title of the symposium is: Photo-Induced Space Charge Effects in Semiconductors: Photoconductivity, Spectroscopy and Electro-Optics. Travel and registration funds for students and post-doctoral attendees for this symposium is requested. Of the submitted abstracts, at least two from students and post-docs will be elevated to the status of invited talks. Travel and registrations for these two speakers are requested. In addition, funds for partial support for 4 additional students or post-docs are requested in order to ensure that good speakers will be able to attend who would not otherwise have the resources. The technical content of the symposium centers around the photorefractive effect and application to semiconductor structures. The photorefractive effect is a space- charge phenomena. It operates through the generation of photocarriers in a high- resistivity sample, followed by photoconductive transport and trapping of the charge at defects. The photogenerated space-charge fields alter the optical properties of the sample through the electro-optic effect. The photorefractive effect is one of the most attractive optical nonlinearity for applications of all-optical control and image processing because it requires very low light intensities. This low-light requirement is a direct consequence of the storage of space-charge on defects, allowing low light intensities to be integrated over time. Applications include phase conjugation, optical amplification and spatial light modulators. Recent advances in the photorefractive effect are using the electro-optic properties of quantum-confined structures ?Nolte, 1990!. The role of the photo- induced space-charge in these photorefractive quantum wells is closely analogous to the feedback that occurs in self electro-optic devices.
