Determination of the non-resonant non-linear refractive index of germano-silicate glass fiber with an arbitrary GeO2 concentration profile

We propose a new method to measure the non-resonant third-order optical non-linearity of germano-silicate glass fiber having arbitrary GeO2 concentration profile using wavelength dependence of mode field diameter. The measured non-linear refractive indices of Samsung’s single mode fiber and the Sumitomo’s highly non-linear optical fiber were found to be in good agreement with the published results within 3.2% and 3.1% error, respectively. The method is applicable only for the optical fibers whose dispersion is dominated by the material dispersion.