Patent ID: 9673899
Date: 2017-06-06
CPC Classifications: H04B,H04J

Claim:
1. A method for estimating an Optical Signal-to-Noise Ratio (OSNR), on a polarization-multiplexed optical Signal-Under-Test (SUT) comprising two polarized phase-modulated data-carrying contributions and an optical noise contribution, the method comprising: for each of a multiplicity of distinct polarization-analyzer conditions, analyzing said SUT to provide at least one polarization-analyzed component of the SUT and detecting said at least one component with an electronic bandwidth at least ten times smaller than the symbol rate of said SUT to obtain a corresponding acquired electrical signal; for each acquired electrical signal, determining a value of a statistical parameter from the ac component of the acquired electrical signal, thereby providing a set of statistical-parameter values corresponding to said multiplicity of distinct polarization-analyzer conditions; and mathematically determining, from the set of statistical-parameter values, said OSNR representative of said optical noise contribution.