Self-deflection of screening-photovoltaic spatial solitons in biased photovoltaic photorefractive crystals.

The self-deflection of a solitary wave arising from diffusion effects in a biased photovoltaic photorefractive crystal has been systematically investigated by employing numerical techniques. Adjusting both strength and polarity of the biased field can change the bending angle of the screening-photovoltaic (SP) soliton, and it is more effective by adjusting the polarity than by adjusting the strength. The stronger the input intensity is, the larger the bending angle is for a dark SP soliton, whereas the bending angle tends to decrease for very weak input intensity as well as for a very strong one, and has a larger value between these two regimes for a bright SP soliton. The dark SP soliton deflects left, whereas the bright one deflects right. The self-bending process of a SP soliton still occurs in a lossy crystal. If the input optical beam is a Gauss beam, whether it can evolve into a stable SP bright soliton or not in the crystal, it will bend with distance. [ABSTRACT FROM AUTHOR]