OPTICAL SIGNAL-TO-NOISE MONITOR HAVING INCREASED COHERENCE

摘要

Methods and apparatus for rapid, accurate OSNR measurements by directly measuring the spectrally-resolved State of Polarization (SOP) variation access each DWDM channel and using a polarization controller (304) to deterministically extinguish the signal across narrow frequency subbands within each DWDM channel. In-band ASE noise is subsequently measured as a 5 function of frequency across the channel bandwidth.