Reliable Determination of Optical Fiber Nonlinearity Using Dispersion Simulations and Improved Power Measurements

We have improved the accuracy of the continuous-wave self-phase modulation method for measuring the nonlinearity of optical fibers. Evaluation of the measurement uncertainty shows that the most significant source of uncertainty is the measurement of fiber-optic power. However, chromatic dispersion can also have a significant effect on the apparent results if it is not taken properly into account. We demonstrate means to achieve an expanded uncertainty of 2% (coverage factor k=2) for the measurement of the nonlinear coefficient n₂ /A_eff. Also, the metrological aspects related to the determination of the nonlinear coefficient and the measurement uncertainty are discussed