Recent Applications of Photochromic Sol-Gel Materials

Abstract

Among the developments associated with sol-gel materials, of relevance is the entrapment of photochromic molecules. Photochromic-doped sol-gel gel-glasses can be prepared by adding a spiropyrane photochromic dye to a solution of ethoxy silane monomers containing non-reacting ethyl radicals. After polymerization, normal photochromism (i.e., colored material upon UV irradiation) is obtained in the resulting matrix. The sol-gel matrix strongly affects the photohhermal reactions of the embedded organic molecule. If these materials are attached to optical fibers, the properties of the light throughput may be modified. An approach to optical memory applications by writing and erasing on newly developed photochromic and thermochromic materials is reported. In this report we emphasize on some of the applications of doped sol-gel glasses, reviewing past results and describing recent progress, mainly in our laboratories.