The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 08, 1980
Filed:
May. 30, 1978
Bor-Uei Chen, Northridge, CA (US);
Antonio C Pastor, Santa Monica, CA (US);
Gregory L Tangonan, Oxnard, CA (US);
Hughes Aircraft Company, Culver City, CA (US);
Abstract
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.