Interaction of photorefractive spatial solitons

I present experimental and theoretical studies concerning the interaction and collision of photorefractive screening solitons. We will show that coherent interactions leads to effects such as soliton fusion, energy exchange, "birth" and annihilation of solitons. In case of incoherent solitons the outcome of interaction depends on geometry of interaction. In particular, we show that two solitons may experience both, attractive and /or repulsive forces depending on their mutual separation and location