Abstract: A method for preparing a material so as to exhibit second harmonic generan for optical radiation that passes through the material. The method includes a first step of providing a bulk glass comprised of substitutionally doped silica and a charge transfer dopant. The bulk glass is prepared for frequency doubling in accordance with a method that includes a step of irradiating the bulk glass with optical radiation having a first wavelength and a second wavelength, the bulk glass being irradiated for a period of time sufficient to obtain a desired amount of conversion efficiency of the first wavelength into the second wavelength. The silica is substitutionally doped with an element selected from the group consisting of Ge and Al, and the charge transfer dopant is selected from the group consisting of Ce.sup.3+, Nd.sup.3+, and Eu.sup.2+. In another embodiment of the invention the silica is substitutionally doped with Ge and the charge transfer dopant is comprised of naturally existing Ge defects.

Abstract: A method of fabricating a periodic nonlinear optic radiation modulation zone within a polymeric waveguide structure. The method includes the steps of (a) providing a layer of a polymeric material having an optically active material that is orientable by an electrical field; (b) applying an electrical field to the layer for orienting at least a portion of the optically active material; and (c) photopolymerizing at least a portion of the polymeric layer for fixing the oriented optically active material into the oriented position. In accordance with one embodiment the step of photopolymerizing includes the steps of (d) generating a diffraction pattern within the polymeric layer, the diffraction pattern being characterized by bright and dark fringes; and (e) photoplymerizing a volume of the polymeric layer within substantially only portions thereof that correspond to the bright fringes.

Abstract: A number of ordered colloidal suspension Bragg reflection optical devices are disclosed each of which comprises a receiver for receiving incident electromagnetic radiation, a modulator, responsive to at least one characteristic of the received radiation, for modulating the received radiation and an emitter for emitting the modulated radiation. The receiver, modulator and the emitter comprise a crystalline colloidal suspension having a lattice structure comprised of a plurality of parallel planes of ordered, electrically charged spheres suspended in an optically active medium, adjacent ones of the planes having a substantially uniform spacing therebetween. The optically active medium comprises molecules selected to have a predetermined index of refraction, radiation absorption, radiation emission or a nonlinear optical response property at a wavelength substantially equal to twice the spacing between the planes.