Tunable self-focusing and self-steering of nematicons

We investigate, both experimentally and theoretically, the nematicon behavior for different degrees of nonlinearity, discussing how the latter affects the beam width (self-focusing) and trajectory (self-steering). Having defined the angle between the molecular director h (i.e., the local optic axis) and the beam wavevector k = n₀k₀z (k₀ is the vacuum wavenumber, n₀ the linear refractive index), the propagation of the extraordinary wave in the plane yz in a homogeneous NLC cell of thickness L across x is ruled by the equivalent 2D model.