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:
Nov. 17, 2009
Filed:
Feb. 12, 2007
Ahmad Atieh, Ottawa, CA;
John Mills, Ottawa, CA;
Ahmad Atieh, Ottawa, CA;
John Mills, Ottawa, CA;
BTI Systems Inc., Ottawa, Ontario, CA;
Abstract
An optical protection switch and a method for optical protection switching are provided. The optical protection switch includes a loop mirror-based optical switch with two circulators and a direction-dependent phase shifter in the loop mirror. The direction-dependent phase shifter introduces phase shifts in counter-propagating optical signals in the loop mirror such that either one of a first optical signal and a second optical signal are switched as an output optical signal. The direction-dependent phase shifter is controlled by a controller which initiates switching from the first optical signal to the second optical signal if a drop in power level is detected in the first optical signal and a corresponding drop in power level is not detected in the second optical signal and vice versa.