Digital optical switch
CA 2042007 C · Owner: Koninklijke Kpn N.V. · Inventors: Doeksen, Doeke Kornelis; Van Der Tol, Johannes Jacobus Gerardus Maria
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
In a digital optical switch which is based on the modeselectivity principle, made up of a passive section (A) containing a first optical wave guide (1) and a second optical wave guide (2) and a switching section (B) containing a third optical wave guide (3) and a fourth optical wave guide (4), both the required asymmetry and the bringing of the optical wave guides within or outside each other's interaction region are achieved with the aid of curves (K1, K2) in said optical wave guides. In the switching section (B) said asymmetry is switchable. Use is made of the effect that a curve results in general, in a reduction of the propagation constant in the optical wave guide. Suitable curves are …
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 May 7, 1991 and granted April 12, 1994. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 7, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 7, 2013.
- 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.