METHOD AND DEVICE FOR MEASURING DOUBLE REFRACTION OF OPTICAL FIBER, METHOD OF MEASURING POLARIZATION MODE DISPERSION OF OPTICAL FIBER AND OPTICAL FIBER

摘要

It is an object of the invention to measure the birefringence and PMD of a short optical fiber (2) in the free state with accuracy. This method comprises the steps of generating pulse light from a pulse light generating means (12); converting polarized state of the pulse light by a polarization conversion means (13); inputting the converted pulse light to one end of the optical fiber (2); and detects the polarization state of backscattered light returning to the one end; acquiring the round-trip Jones matrix R(z) for a first interval (0,z); acquiring the round-trip Jones matrix R(z+Δz) for a second interval (0,z+Δz); determining the eigenvalues p1, p2 of the matrix R(z+Δz)R(z)-1; and obtaining the birefringence in the infinitesimal interval Δz by computing the following equations (1) and (2). φ represents the phase difference between linear polarization components due to birefringence, Δn represents birefringence, and λ represents wavelength.