The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 24, 2001
Filed:
Dec. 23, 1999
Stephen Day, Harlow, GB;
James E Whiteaway, Sawbridgeworth, GB;
Alan Fielding, Bishop's Stortford, GB;
Terry Clapp, Standon, GB;
Nortel Networks Limited, Montreal, CA;
Abstract
It is found that the use of a multimode interference (MMI) section to flatten the pass-bands of an arrayed waveguide grating (AWG) multiplexer/demultiplexer or comb filter introduces undesirable non-linear wavelength dispersion into those pass-bands if that MMI section mixes modes of more than two different orders. This dispersion can be substantially compensated by the use of a tandem arrangement of two AWGs with MMIs of differing length chosen to provide complementary dispersions. In the case of a comb filter, an equivalent compensation can be achieved by arranging for the light to make a second passage through the AWG in the reverse direction.