GLASSES, CERAMICS, POWDERS, MEMBRANES AND COMPOSITES .10. SOL-GEL GLASSES FOR OPTICS AND ELECTROOPTICS

This paper reviews the processing of organic-doped sol-gel gel-glasses for optics and electro-optics. The coupling of low-temperature processing and gel-glass doping with organic photoactive or electroactive molecules opens new opportunities for optical and electro-optical applications. The manuscript focusses on the requirement of precise control of compositional and pore surface variations in cage trapped molecules of different optical and electro-optical gel-glasses. The methods used for achieving this goal are related. These involved combinations of molecular precursors and polymerizing conditions. Examples are given for fluorescent gel-glasses, room-temperature phosphorescent gel-glasses and photochromic gel-glasses with a combination of optical properties. Gel-glass dispersed liquid crystal (GDLC) with electro-optical properties are also described. The sensitivity and the photophysical behavior and properties of the trapped organic molecules have been used to observe the structural changes that occur in a polymerizing system of silicon alkoxides in ceramer composites and in a reversed phase silica obtained by the sol-gel technique.