Observation of asymmetric solitons in waveguide arrays with refractive index gradient

摘要

We study light propagation in waveguide arrays made in Kerr nonlinear mediawith a transverse refractive index gradient, and we find that the presence ofthe refractive index gradient leads to the appearance of a number of newsoliton families. The effective coupling between the solitons and the localizedlinear eigenmodes of the lattice induces a drastic asymmetry in the solitonshapes and the appearance of long tails at the soliton wings. Such unusualsolitons are found to be completely stable under propagation, and we reporttheir experimental observation in fs-laser written waveguide arrays withfocusing Kerr nonlinearity.