Patent Yard Sign in
Expired Canadian patentCanada

Controllable polarisation transformer

CA 2092778 C · Owner: Koninklijke Ptt Nederland N.V. · Inventors: Van Der Tol, Johannes Jacobus Gerardus Maria

CIPO record

Overview

Drawings and full text

Its claims, description and drawings are in the Canadian Patents Database.

Open the CIPO record

Abstract From the Canadian patent

Controllable polarisation transformer comprising a passive mode converter (4), a controllable phase shifter (5) and a controllable Mach-Zehnder interferometer (7). The mode converter (4) converts the first signal component of one polarisation (TE or TM) of a light signal entering via an input (1) into a signal component of the other polarisation without affecting the second signal component of the other polarisation (TM or TE) the, conversion taking place to another order of the guided mode. Phase control by means of the phase shifter (5) controls the intensity distribution of the light signal over the two branches (8, 9) of the interferometer (7). Optical wavelength control in the …

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 March 26, 1993 and granted February 24, 1998. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 26, 2013.
  • A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 26, 2015.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledMarch 26, 1993
GrantedFebruary 24, 1998
Term endedMarch 26, 2013
Patent numberCA 2092778 C
Classification (IPC)G02F1/22 +1 more

Timeline

Timeline From CIPO dates

1994199619982000200220042006200820102012Application filedMarch 26, 1993Patent grantedFeb 24, 1998Term endedMarch 26, 2013

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.