Simulation and evaluation of frequency coupling coefficients in the nonlinear dispersive regime of single-mode fibers

We investigated the IM-IM and IM-PM coupling (conversion) coefficients of a microwave modulated optical link, where a Bragg grating is inserted. The Bragg reflector allows measurements accessing only to one fibre ends, and simultaneously increases the transmission length. Numerical simulations of the IM-IM and IM-PM coupling coefficients are realized as a function of the modulation frequency, fibre length and laser power, using the method derived by Ramos and Marti. The experimental measurements deviated considerably from the theoretical expressions, particularly at low powers (< 10mW). We expect the method to be useful to measure non-linear and dispersive characteristics of installed fibre links.