OPTICAL FIBER BIREFRINGENCE MEASUREMENT METHOD AND MEASUREMENT DEVICE, AND OPTICAL FIBER POLARIZATION MODE DISPERSION MEASUREMENT METHOD AND OPTICAL FIBER

摘要

In a method of measurement of the birefringence of an optical fiber, the round-trip Jones matrix R(z) for a first interval (0, z) from a measurement starting point 0 in the optical fiber for measurement to a prescribed position z, and the round-trip Jones matrix R(z+Deltaz) for a second interval (0, z+Deltaz) from the measurement starting point 0 to a position z+Deltaz differing from the position z, are acquired, the eigenvalues rho₁, rho₂ of the matrix R(z+Deltaz)R(z)^-1 are determined, and by computing the following equations (1) and (2), $\begin{array}{cc}\varphi =\frac{\arg \left(\frac{{\mathrm{rho}}_1}{{\mathrm{rho}}_2}\right)}{2}& \left(1\right)\\ \mathrm{Delta}n=\frac{\mathrm{lambda\varphi }}{2\mathrm{pi}.\mathrm{Delta}z}& \left(2\right)\end{array}$ (where phi represents the phase difference between linear polarization components due to birefringence, Deltan represents birefringence, and lambda represents wavelength), the birefringence in the infinitesimal interval Deltaz from the position z to the position z+Deltaz is obtained.