All-optical phase-independent logic elements based on phase shift induced by coherent soliton collisions

International audienceWe demonstrate, for the first time to our knowledge, that a fast coherent collision between two Kerr spatial solitons can give rise to a significant phase shift for both interacting beams. The maximal collision-induced phase shift rad takes place when the amplitudes of the solitons are equal (1 = 2) and the length of the interaction zone is comparable with a soliton phase period. Depending on the ratio 2 1 and the collision angle between the solitons, the magnitude of the phase shift can be varied within a reasonable range, for example from 180 to 40. The analysis of the effect performed by the finite-difference beam-propagation method has shown that it is insensitive to the initial phase difference between the incident beams (), even in the case when 1 = 2. It has been demonstrated that the phenomenon can be used for all-optical three-soliton logic elements, which are capable of providing more than 3-dB signal amplification and possess -independent output characteristics