Collapse Dynamics of Vortex Beams in a Kerr Medium with Refractive Index Modulation and PT-Symmetric Lattices

Using the two-dimensional nonlinear Schrödinger equation, collapse dynamics of vortex beams in a Kerr medium with refractive index modulation and parity–time (PT) symmetric lattices are explored. The critical power for real optical (i.e., lattices) was obtained discussed. Numerical calculations showed that number self-focusing points, locations collapse, propagation distances sensitively dependent on factors, topological charge numbers, initial powers. When field propagates lattices, will into symmetrical shape. However, shape beam be chaotically distorted asymmetric patterns during PT-symmetric because presence complex refraction index. Introducing materials may offer new approach to controlling beams.