Patent ID: 9596027
Date: 2017-03-14
CPC Classifications: H04B,H04J

Claim:
1. A method for determining a quality parameter characterizing a polarization-multiplexed optical signal-under-test (SUT) propagating on an optical communication link and comprising at least a data-carrying signal contribution and an Amplified Spontaneous Emission (ASE) noise contribution within an optical signal bandwidth, the method comprising: measuring, using an optical spectrum analyzer, a test optical spectrum trace of said optical signal-under-test corresponding to a test point along said optical communication link, said test optical spectrum trace extending over a spectral range encompassing at least a portion of said optical signal bandwidth; using a computing device: obtaining a reference optical spectrum trace corresponding to a reference signal; estimating a spectral deformation of said signal contribution of said signal-under-test compared to said reference optical spectrum trace, within said spectral range, using said reference optical spectrum trace and said test optical spectrum trace, wherein the spectral deformation is at least partially induced by non-linear effects; and determining said quality parameter at least from the estimated spectral deformation; and outputting the determined quality parameter.