The influence of 3-photon absorption and pulse interactions on discrete X-waves in normally dispersive waveguide arrays

In this paper, we investigate the influences of 3-photon absorption on discrete X-waves in nonlinear normally dispersive waveguide arrays. It is found that 3-photon absorption can cause the decrease of the total power, which results in the appearances of the discrete diffraction for an intermediate input peak-power and the discrete X-wave for a higher input peak-power. Also, the interaction between pulses for different waveguide excitation are studied in detail. The results show that for the in-phase waveguide excitation of neighboring channels, the bound states can be formed by choosing properly the initial peak-power; for the in-phase waveguide excitation of distant channels, however, the bound states can not be formed. For the out-of-phase multiple waveguide excitation, due to interplay the repulsive force and nonlinearity, the interaction of two pulses can form the X-like wave or the double X-like wave as long as choosing the proper input peak-power.