Screening dark spatial solitions in photorefractive materials

In this paper, the dynamical evolution of dark screening solitons in PR media was investigated under steady-state conditions. Our numerical study indicates that these optical dark soliton at lower power level are stable against small perturbations whereas those at higher power level will split into pairs of dark spatial solitons. The influence of loss in refractive materials is studied in detail. The effect of the external bias field on the self-defocusing behavior of dark optical beam is also discussed.