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:
Feb. 26, 2002
Filed:
Mar. 17, 1998
Christopher Richard Doerr, Middletown, NJ (US);
Yuan P. Li, Duluth, GA (US);
Agere Systems Optoelectronics Guardian Corp., Orlando, FL (US);
Abstract
An optical add-drop multiplexer (ADM) avoids waveguide crossings by being constructed in the form of a Mach-Zehnder interferometer having a demultiplexer/multiplexer (demux/mux) pair in each of its arms. Each demux/mux pair is interconnected by coherent connecting paths having heating elements for increasing the path length of selected connecting paths. Waveguide optical couplers having asymmetric transfer functions are used at the input and output of the ADM. These couplers cooperate with the activated heating elements to add and/or delete a selected optical channel to/from an optical transmission path. Each coherent connecting path includes a number of waveguides. The end-to-end transmission characteristic of the ADM through each individual waveguide has a Gaussian shape. These Gaussian shapes are designed intersect at their −3 dB wavelengths so that the end-to-end transmission characteristic of the ADM is flat.