COST 241 intercomparison of nonlinear refractiveindex measurements in dispersion shifted optical fibres at λ=1550 nm

Abstract
COST 241 measurements of the nonlinear refractive index, n2, exhibit a large scatter depending on the specific measurement technique. This is largely due to the electrostrictive contribution to the Kerr nonlinearity, as is revealed by the resonant behaviour of n2 (with peak values up to 3.9 10-20 m2 W-1) observed with signal modulation frequencies in the 0.1–1 GHz range.