The soi-gei process is based on the mixing of liquid reactants on a molecular scale and the
subsequent solidification of the solution into a porous amorphous oxide gel. The porous gel is then heated
to give glasses or poiycrystailine solids. Additives can be made to the liquid mixture to give composites.
Many new optical materials have been prepared by the sol-gel technique in the past five years. The present
status of the scientific understanding of the process is summarized and examples presented of different
types of materials successfully developed for optical applications. The enormous potentials of the process
are not fully exploited at present. Sol-gei optics promises to be a growing field of science and technology.