By: Chao Hang
At: Complexo Interdisciplinar, Anfiteatro
We consider propagation of a light beam propagating in a resonant three-level atomic system in the persence of electromagnetically induced transparency (EIT). In such a system stable two-dimentional spatial solitons and as well as several types of instabilities can be observed. Different dynamical regimes can be implemented by simple control of the lattice parameters, achiavable by change of either the geometry of the control field or its intensity. We employ a unified theory to solve the respective nonlinear system with different geometries of the control fields inducing an optical lattice. The formation of spatial solitons and instabilities are studied both analytically and numerically. Different from conventional passive optical media, the solitons in such resonant system can be created by light at a very weak intensity.