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:
Jan. 31, 2006
Filed:
Oct. 09, 2002
Shigeru Yoneda, Tokyo, JP;
Shigeru Yoneda, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
An array waveguide diffraction gratingas waveguide type optical device comprises a planar lightwave circuitwith an optical waveguide layerformed on a silicon substrateand having a predetermined thickness h, a first compensation substratebonded to the side of the optical waveguide layerand having a thickness hand a second compensation substrateformed on the silicon substrateand having a thickness h. The linear expansion coefficients αand αof the two compensation substratesandare set to be greater than that of the optical waveguide elementand highly rigid adhesives are used as a first and a second adhesiveandIt is thus possible to have the contraction of the optical waveguide elementdue to a temperature change increased with the first and second substrates, thus permitting the center frequency setting to a desired value in a predetermined temperature range. Similar effects are obtainable by merely providing a support substrate on the substrate side of the optical waveguide element