We show that optically induced photonic lattices in a nonconventionally biased photorefractive crystal can support the formation of discrete and gap solitons owing to a mechanism that differs from the conventional screening effect. Both the bias direction and the lattice orientation can dramatically influence the nonlinear beam-propagation dynamics. We demonstrate a transition from self-focusing to -defocusing and from discrete to gap solitons solely by adjusting the optical-beam orientation.
© 2008 Optical Society of America
Original Manuscript: November 26, 2007
Revised Manuscript: February 3, 2008
Manuscript Accepted: February 21, 2008
Published: April 14, 2008
Peng Zhang, Sheng Liu, Jianlin Zhao, Cibo Lou, Jingjun Xu, and Zhigang Chen, "Optically induced transition between discrete and gap solitons in a nonconventionally biased photorefractive crystal," Opt. Lett. 33, 878-880 (2008)