Method for fabrication of wavelength selective electro-optic grating for dfb/dbr lasers
CA 2136254 A1 · Owner: American Telephone And Telegraph Company · Inventors: Chiu, Tien-Heng; Williams, Michael D.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method is described for the preparation of a DFB/DBR laser which includes an electro-optic grating formed by periodically modulating the index of refraction of the cladding employed. The method involves depositing a waveguide upon a semi-insulating or doped substrate and then depositing an active layer upon the resultant structure. The active layer is subsequently selectively etched and a cladding material deposited adjacent thereto and electrically isolated therefrom. The cladding is then selectively patterned with a conductive material by photolithographic techniques to yield a grating to periodically modulate the index of refraction.
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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 November 21, 1994. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended November 21, 2014.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by November 21, 2016.
- 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
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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.