Semiconductor lasers
CA 1265604 C · Owner: British Telecommunications Public Limited Company · Inventors: Westbrook, Leslie David
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The emission linewidth of a semiconductor laser can be reduced by operating it at a wavelength which is less than the wavelength of maximum gain at the threshold current, .lambda. max. An assembly for carrying out such operation comprises a ridge waveguide laser provided with a distributed feedback (DFB) grating. The period of the grating is selected to give a predetermined emission wavelength to the laser which is shorter than .lambda. max. The invention finds application in optical communications particularly, in coherent systems.
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
- Granted February 6, 1990. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended February 6, 2007.
- 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.