OPTICAL TRANSMISSION SYSTEM AND METHOD FOR MONITORING POLARIZATION DEPENDENCE CHARACTERISTIC OF OPTICAL TRANSMISSION LINE

摘要

PROBLEM TO BE SOLVED: To measure a characteristic of an optical transmission line which depends on a polarization state, in a short time.SOLUTION: A first digital signal processor comprises: a frequency controller for sweeping a frequency of an optical signal by controlling an electric field information signal; and a polarization controller for controlling a polarization state of the optical signal by controlling mixture of a first electric field information signal corresponding to a first transmission signal and a second electric field information signal corresponding to a second transmission signal. The polarization controller provides a plurality of different transmission polarization states for each frequency when sweeping of the frequency of the optical signal is being performed. A second digital signal processor acquires polarization dependence characteristics corresponding to a plurality of different frequencies by calculating a polarization dependence characteristic of the optical transmission line on the basis of a plurality of pieces of reception electric field information corresponding to the plurality of different transmission polarization states for each frequency of the optical signal when the sweeping of the frequency of the optical signal is being performed. The second digital signal processor acquires statistical information on the polarization dependence characteristic of the optical transmission line on the basis of the plurality of polarization dependence characteristics.