Multicolor infrared photodetector
CA 2038844 C · Owner: Government Of The United States, As Represented By The Secretary Of The Army (The) · Inventors: Choi, Kwong-Kit
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A multicolor infrared detection device comprising a number of doped quantum well structural units. Each unit consists of a thick well and a thin well separated by a thin barrier. This arrangement produces strong coupling. Infrared radiation incident on the device gives rise to intersubband absorption. For each transition a photosignal results which allows the detection of a plurality of incident frequencies.
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 22, 1991 and granted April 6, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended March 22, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by March 22, 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.