Polarization-maintaining optical fiber
CA 2008451 C · Owner: Messerly, Michael J. · Inventors: Mikkelson, Raymond C.; Messerly, Michael J.; Donalds, Lawrence J.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A single-mode, polarization-maintaining optical fiber has both excellent signal attenuation and resistance to adverse bending effects because (1) its cladding and any portion of the jacket that is within five times the radius of the mode-field in its core have a substantially uniform index of refraction that is at least 0.005 less than that of pure silica, and (2) the index of refraction of the core is at least as great as, but preferably not substantially greater than, that of pure silica. Preferably the, stress-applying region of the fiber is elliptical and the, jacket is pure silica.
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 January 24, 1990 and granted February 3, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 24, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 24, 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.