Nontrivial coupling of light into a defect: the interplay of nonlinearity and topology

摘要

The two illustrations show the tilted excitation (green arrows) for nontrivial (left) and trivial (right) lattices, where the red dot marks the position of the nontrivial edge. (a1–b2) The experimental results obtained with the nontrivial lattice, where (a1) shows the written SSH waveguide lattice examined by a probe beam, (a2) shows the output of a topological edge state under normal (straight) excitation, and (b1) and (b2) show the outputs with a tilted beam (kx = −1.4π/a) in linear and nonlinear cases. (b3) The simulation results show a side-view (up to a crystal length of 20 mm) of the beam dynamics under nonlinear excitation. The right panels (c1–d3) have the same layout as the left panels except that the results are obtained with the trivial lattice. The white dashed-dotted line marks the edge position of the SSH lattice in all figures