Patent ID: 6396575
Filing Date: 2002-05-28
Classification: G01M

Abstract:
An apparatus for measuring transmission loss in a passive optical network (PON) transmitting optical signals from an optical fiber to each of N branches, said apparatus comprising:means for launching optical pulses into the PON, said optical pulses having different known states of polarization; polarization markers deployed with each branch of the passive optical network for introducing a unique polarization dependent loss (PDL) in the corresponding branch of the PON; means for measuring the backscatter of the optical pulses from the PON as a function of time, for each of the different known states of polarization; and means for deriving the transmission loss based on the backscatter of the optical pulses for each of the different known states of polarization, wherein the unique PDL associated with each branch is used as the basis for distinguishing the branches of the PON from each other.