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. 07, 2006
Filed:
Sep. 18, 2001
Egbert Krause, Burgstaedt, DE;
Adalbert Bandemer, Herrsching, DE;
Egbert Krause, Burgstaedt, DE;
Adalbert Bandemer, Herrsching, DE;
Thorlabs GmbH, Karlsfeld, DE;
Abstract
A PMD emulation, measurement and compensation device is based upon an emulation device having a piece of fiber having a fixed differential group delay (DGD) and another short piece of fiber (or double refracting crystal) having a variable differential group delay (T-DGD). The two pieces of fiber are coupled with a non-zero torsional angle between their respective double refractive axes, preferably 45°. A fiber squeezer/stretcher is used to provide the variable DGD for the short piece of fiber. Various serial couplings of DGD and T-DGD fiber may be added to provide greater control and accuracy, with the torsional angles preferably alternating. Such an emulation device may be incorporated into a measurement device to measure the PMD-related distortion of an optical signal. Further the measurement device may be used in a PMD compensator where an emulation device in series with the optical signal path is controlled until the measured PMD in the PMD-related distorted optical signal is minimized.