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:
May. 09, 2006
Filed:
Jan. 21, 2004
Shigenori Aoki, Sunnyvale, CA (US);
Kishio Yokouchi, San Jose, CA (US);
Hiroshi Nagaeda, Kitahiroshima, JP;
Kaoru Sugimoto, Kawasaki, JP;
Alexei Glebov, San Mateo, CA (US);
Shigenori Aoki, Sunnyvale, CA (US);
Kishio Yokouchi, San Jose, CA (US);
Hiroshi Nagaeda, Kitahiroshima, JP;
Kaoru Sugimoto, Kawasaki, JP;
Alexei Glebov, San Mateo, CA (US);
Fujitsu Limited, Kawasaki, JP;
Abstract
The intensity of signals in optical networks can be controlled using a variable optical attenuator (VOA). The present invention is a VOA that is particularly well suited for optical networks, for example to provide channel-by-channel normalization of gain control of wavelength division multiplexed signals. The inventive VOA includes a waveguide having a cladding that includes an electro-optical material and electrodes that produce an electric field within the electro-optical material when a voltage difference is applied to the electrodes. The VOA also includes a layer that is parallel to the core of the waveguide and that optically couples to the core to receive light from the attenuated signal. A power meter receives light from the layer as an indication of the amount of light attenuated from the signal and for controlling the voltage to the electrodes.