Quasiperiodic envelope solitons

We analyze nonlinear wave propagation and cascaded self-focusing due to sec ond-harmonic generation in Fibbonacci optical superlattices and introduce a novel concept of nonlinear physics. the quasiperiodic soliton, which descr ibes spatially localized self-trapping of a quasiperiodic wave. We point ou t a link between the quasiperiodic soliton and partially incoherent spatial solitary waves recently generated experimentally.