Energy exchange between (3+1)D colliding spatiotemporal optical solitons in dispersive media with cubic--quintic nonlinearity

We investigate the energy exchange between (3+1)D colliding spatiotemporal solitons (STSs) in dispersive media with cubic--quintic (CQ) nonlinearity by numerical simulations. Energy exchange between two (3+1)D head on colliding STSs caused by their phase difference is observed, just as occurring in other optical media. Moreover, energy exchange between two head-on colliding STSs with different speeds is firstly shown in the CQ and saturable media. This phenomenon, we believe, may arouse some interest in the future studies of soliton collision in optical media.