Hughes Aircraft Company

Bor-Uei Chen

Gregory L Tangonan

Antonio C Pastor

There is disclosed a method by which a three-dimensional horn structure at the end of a channel waveguide in a dielectric chip is produced to facilitate coupling of a fiber optic waveguide by butt coupling techniques. The three-dimensional horn structure is fabricated by localized surface diffusion resulting from superposing a CO.sub.2 laser heating beam on the desired enlarged area while diffusion of the waveguide is taking place or after it has taken place in a controlled ambient furnace atmosphere.

Method of laser enhanced thermal diffusion

The specification describes an optical waveguide device formed by diffusing a metal into a substrate which may be either a semiconductor material or a dielectric material. The substrate is first coated with a liquid composition comprising organo-metallic solutions of the desired metal and silica. The coated substrate is then heated at an elevated temperature for a period of time sufficient to cause the organic portion of the solution to decompose, thereby leaving a composite film comprising an oxide of the desired metal and SiO.sub.2. Upon further heating, the metal from the metal oxide diffuses into the substrate. The residual composite film may be left in place or removed.

Optical waveguide formed by diffusing metal into substrate

Apparatus is provided comprising a laser source, a collimating lens, a focussing lens and a detector array disposed along an optical path. A surface acoustic wave transducer is disposed between the collimating and focussing lenses and is adapted to modulate laser light provided by the laser source as a function of the amplitude and frequency of energy applied to the transducer. In accordance with the invention, a 90.degree. Bragg diffraction grating disposed between the collimating lens and the transducer, is adapted for transmitting light of a predetermined frequency and predetermined polarization along the optical path. A specific embodiment incorporates the components on an integrated circuit chip.

RF Spectrum analyzer

The specification describes a process for diffusing a metal into a substrate which may be either a semiconductor material or a dielectric material. The substrate is first coated with a liquid composition comprising organo-metallic solutions of the desired metal and silica. The coated substrate is then heated at an elevated temperature for a period of time sufficient to cause the organic portion of the solution to decompose, thereby leaving a composite film comprising an oxide of the desired metal and SiO.sub.2. Upon further heating, the metal from the metal oxide diffuses into the substrate. The residual composite film may be left in place or removed.

Method for diffusing metals into substrates

A process for suppressing the out-diffusion of Li.sub.2 O from LiNbO.sub.3 and LiTaO.sub.3 waveguide structures by exposing the structures to a Li.sub.2 O-rich environment at sufficient vapor pressure that Li.sub.2 O diffuses into the structure as a compensation process and a solid-solid surface interaction occurs. In one embodiment of the invention, the out-diffusion of Li.sub.2 O from LiNbO.sub.3 and LiTaO.sub.3 crystals into which Ti has been diffused is eliminated by annealing the structure in a high purity powder of LiNbO.sub.3 or LiTaO.sub.3. In a second embodiment, the Li.sub.2 O out-diffusion is partially suppressed by annealing the structure in molten LiNO.sub.3. In a third embodiment of the invention, a waveguide structure comprising a Li.sub.2 O-rich guiding layer is formed by annealing LiNbO.sub.3 or LiTaO.sub.3 crystals in a high purity powder of LiNbO.sub.3 or LiTaO.sub.3, which not only suppresses Li.sub.2 O out-diffusion but also promotes Li.sub.2 O in-diffusion into the crystals.

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Northridge, CA, United States of America

Bor-Uei Chen