Semiconductor laser
CA 2071025 C · Owner: Sumitomo Electric Industries, Ltd. · Inventors: Yoshida, Ichiro
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A p-clad layer constituting the semiconductor laser device according to this invention includes an inner clad area near to an active layer and an outer, clad area remote from the active layer the outer clad, area having a narrower bandgap than that of the inner clad area, the thickness and the composition of the inner clad area being so set that beams do not substantially exude from the active layer to the outer clad area. A multi-quantum barrier structure is provided between the active layer and the p-clad layer. At least one of barrier layers of the multi-quantum barrier structure is formed of a material which applies tensile stress thereto, and at least one of well layers provided …
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 11, 1992 and granted August 10, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 11, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 11, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.