Patent ID: 7655376

Claim:
A process comprising (a) providing a substantially inorganic photoreactive composition comprising (1) at least one cationically reactive species, (2) a multi-photon photoinitiator system, and (3) a plurality of precondensed, inorganic nanoparticles; (b) exposing, using a multibeam interference technique involving at least three beams, at least a portion of said photoreactive composition to radiation of appropriate wavelength, spatial distribution, and intensity to produce a two-dimensional or three-dimensional periodic pattern of reacted and non-reacted portions of said photoreactive composition; (c) exposing at least a portion of said non-reacted portion of said photoreactive composition to radiation of appropriate wavelength and intensity to cause multi-photon absorption and photoreaction to form additional reacted portion and a remaining non-reacted portion; (d) removing said remaining non-reacted portion or the entire reacted portion of said photoreactive composition to form interstitial void space; and (e) at least partially filling said interstitial void space with at least one material having a refractive index that is different from the refractive index of the remaining non-reacted or reacted portion of said photoreactive composition.