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:
Aug. 06, 1991
Filed:
Aug. 31, 1989
Applicant:
Inventors:
Assignee:
GEC-Marconi Limited, Stanmore, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
385130 ;
Abstract
A smoothing layer is provided between the rough etched sides of a channel in a substrate in which an optical waveguiding material is to be produced. Losses are substantially reduced thereby. For a rectangular or rib waveguide, where the sides of the rib are left rough by etching, a smoothing layer is again provided over the rib. The smoothing layer preferably has a refractive index close to or the same as the materials having surface roughness.