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:
Apr. 22, 2003
Filed:
Jan. 17, 2001
Martin Jaspan, Somerville, MA (US);
Sycamore Networks, Inc., Chelmsford, MA (US);
Abstract
A method and apparatus for variable optical attenuation is disclosed. A variable optical attenuator is provided having a housing. Within the housing, a filter is mounted on a drive shaft of a motor such that the drive shaft passes through a substantially center point of the filter. The filter has a monotonically increasing filter gradient that begins at a lower optical density and gradually increases in optical density in a diametrical pattern. An input optical fiber provides a light signal to be attenuated. The input optical fiber introduces the light signal, which passes through a first collimator, through the filter, through a second collimator, and to an output optical fiber which exits the housing. When activated, the motor rotates the drive shaft to position the filter to a desired attenuation position for attenuating the light signal.