Optical system including wavelength tunable semiconductor laser
CA 2015482 C · Owner: American Telephone And Telegraph Company · Inventors: Schubert, Erdmann Frederick; Cunningham, John Edward; Harris, Timothy Dean
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Optical systems which include a particular type of wavelength-tunable semiconductor laser are disclosed. Significantly the active layer of the laser, includes a doping superlattice layer. Even more significantly wavelength-tunability, is achieved by nonuniformly optically and/or electrically pumping the laser.
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 April 26, 1990 and granted March 29, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 26, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 26, 2012.
- 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.