Dynamic soliton modes

Summary form only given. In the past few years, spatially incoherent solitons have attracted much research interest. One necessary condition to observe the spatially incoherent solitons is that the nonlinearity must be "non-instantaneous", namely, the nonlinear response of medium is slow enough that it cannot respond to the relatively rapid local intensity fluctuation of the optical beam. The medium only "see" the time-averaged light intensity in the order of the material response time, generating a spatially smooth and temporally constant waveguide that can accommodate all the constitutive modes of the soliton beam. How fast the local intensity should fluctuate to make the nonlinearity of the medium look "non-instantaneous" in order to form incoherent solitons? To target such problems for the first time and to clearly observe the dynamic soliton behavior, we study experimentally with the bicomponent solitons in a slow-responding photorefractive SrBaNb/sub 2/O/sub 6/ (SBN) crystal, which belong to the least complex category of the spatially partially incoherent solitons.