METHOD AND APPARATUS FOR MEASUREMENT OF POLARIZATION MODE DISPERSION

摘要

PROBLEM TO BE SOLVED: To measure the polarization mode dispersion of an optical transmission medium by actually measuring Jones' vector which uses normalized Stokes vectors as components. SOLUTION: Three kinds of beams of incident light whose polarization state is different are incident on an optical transmission medium 1 from an incidence means 2. Beams of radiant light, in respective polarization state, which have been passed through the optical transmission medium 1 are detected as Stokes vector quantities by optical intensity detectors 9o , 9a to 9c . A Jones' matrix calculating and computing part 12 calculates and evaluates Jones' matrix describing the polarization characteristics of the optical transmission medium 1 by using Stokes' vectors. A difference-approximation computing part 13 approximates the difference of the Jones' matrix U(ω) obtained by the light incidence of an angular frequency ω and the Jones' matrix U(ω+4ω) obtained by the incidence of an angular frequency ω+δω. A polarization-dispersion-vector computing part 14 computes a polarization dispersion vector Ω on the basis of a matrix component obtained by the difference approximation. A polarization-mode-dispersion computing part 15 computes the absolute value of the polarization dispersion vector Ω so as to find the polarization mode dispersion of the optical transmission medium 1.