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:
Jun. 12, 2018
Filed:
May. 09, 2016
Fujitsu Network Communications, Inc., Richardson, TX (US);
Emilio Bravi, Hillsdale, NJ (US);
Fujitsu Limited, Kawasaki, JP;
Abstract
Systems and methods for measuring the in-phase/quadrature (I/Q) skew of optical signals. The method may be used to characterize the I/Q skew of optical signals transmitted by optical coherent transponders in complex modulation formats. The method may include providing an input signal to a transponder to produce a periodic (and generally sinusoidal) output signal, providing the output signal to a test system including an optical spectrum analyzer, measuring the optical power of a first harmonic of the signal, and comparing the measured optical power to calibration data to determine the I/Q skew. The optical power may be analyzed in a portion of the spectrum where sensitivity of the power to changes in skew is highest. The calibration data may map previously-obtained optical power measurements to corresponding known skew amounts. The system may provide more accurate skew measurements using less expensive equipment than existing skew measurement methods.