Rotation and oscillation of gap vortex solitons in optically induced square photonic lattices with a self-focusing nonlinearity

Abstract

We demonstrate the rotation and oscillation of the single-charged vortex (SCV) and double-charged vortex (DCV) in two-dimensional (2D) optically induced square photonic lattices under single-site excitation with appropriate self-focusing nonlinearity conditions. Numerical analysis shows that the SCV can self-trap into a localized gap vortex soliton mode that resides in the first Bragg reflection gap, for which a vortex is nested centrally in the rotating square-shaped optical envelope and four peaks always appear at four corners. Whereas DCV tends to evolve into a dynamical rotating quasi-vortex gap soliton formed in the second Bragg reflection gap, employing an out-of-phase quadrupole-like beam as a transition state to reverse the topological charge and the direction of rotation periodically. Our findings may provide insights into the experimental feasibility of observing such phenomena.

Optical fabrication of (2 + 1)-dimensional photorefractive photonic lattices by improved Billet split lens

“…The optical induced method utilizes multi-beam interference and photorefractive materials to prepare photonic lattices, which is a very promising method. At present, many quantized optical phenomena (such as optical Bloch oscillations, dynamic localization, tunneling control) have been discovered in optically induced photorefractive photonic lattices, and many meaningful achievements have been made [17][18][19][20][21][22][23]. However, in these related experimental studies, the optical devices used to produce photonic lattices are complex and difficult to adjust, or rely on expensive equipment.…”