Introduction

Abstract

Much progress has been made in the last decade in using light as an information carrier. Optical telecommunication using optical fibers and optical displays using liquid crystalline or polymeric light emitting materials are the best-known examples of these fast growing areas. It is expected that optical information technology will expand rapidly at a rate that roughly doubles transport, processing and storage capacity every three years. Within a decade, information transport networks of terabits per second, storage of terabytes and ultrafast processing systems with teraoperations per second should be realized [1]. It is believed that a large fraction of the elements for these technologies will use light as the information carrier. For this reason the search for new materials and the investigation of older materials are very important tasks.