NONLINEAR REFRACTIVE INDEX MEASURING METHOD AND DEVICE FOR SINGLE MODE OPTICAL FIBER

摘要

PROBLEM TO BE SOLVED: To measure a nonlinear refractive index by using a correction coefficient according to a group velocity dispersion value of a single mode optical fiber. SOLUTION: The spectral width of an output optical pulse of a measured optical fiber with respect to each input power value is measured, the spectral spread of the spectral width with respect to the input spectral width is calculated, and the nonlinear refractive index n2 ' of the measured optical fiber is obtained from the gradient of a straight line produced when the spectral spread becomes a linear function of the input power. The correction coefficientξexpressed as a function of Leff /Ld obtained by dividing the effective fiber length Leff of the measured optical fiber by the dispersion length Ld is found by numerical calculation, and the nonlinear refractive index n2 ' obtained by the measurement is multiplied by the correction coefficientξ, so that a nonlinear refractive index n2 compensated for influence of wavelength dispersion is calculated.