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:
Mar. 29, 2005
Filed:
Nov. 06, 2002
Motoyuki Nishizawa, Kawasaki, JP;
Masatoshi Ishii, Kawasaki, JP;
Masayuki Kato, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An optical waveguide comprising an MgO substrate, and a slab waveguide layerformed on the MgO substrateand including a core layerof a ferroelectric or an antiferroelectric, further comprises a stress alleviating layerwhich substantially lattice-matches with the MgO substrate and the slab waveguide layerand has an average thermal expansion coefficient in the range of 7.0×10-14.0×10/° C. at the room temperature to 700° C. Accordingly, the optical waveguide device utilizing the magnesium oxide substrate can be formed without breaking the optical waveguide layer and the magnesium oxide substrate itself.