Generalised dispersive phase and its effect on four wave mixing in fibers

A generalised method of calculating the efficiency of four wave mixing products in an optical fiber is presented in this paper. Apart from indicating the insufficiency of the existing theoretical model, this work brings out the importance of calculating the dispersive phase shift more precisely in combination with the nonlinear phase shift to predict the efficiencies of sideband generation. The experimental results for the generation of the first and second order sidebands are analysed. Contrary to expectations, higher powers and longer lengths of fiber do not result in larger number of sidebands. An attempt is made to understand this aspect as well as the experimentally observed fluctuations in the four wave mixing products.