Spectral discrete solitons: from cnoidal waves to spatio-temporal helical beams
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Thu, 25/11/2010 16:00 |
Andrey Gorbach (University of Bath) |
Differential Equations and Applications Seminar  |
DH 1st floor SR |
| In my talk I will introduce the concept of spectral discrete solitons (SDSs): solutions of nonlinear Schroedinger type equations, which are localized on a regular grid in frequency space. In time domain such solitons correspond to periodic trains of pulses. SDSs play important role in cascaded four-wave-mixing processes (frequency comb generation) in optical fibres, where initial excitation by a two-frequency pump leads to the generation of multiple side-bands. When free space diffraction is taken into consideration, a non-trivial generalization of 1D SDSs will be discussed, in which every individual harmonic is an optical vortex with its own topological charge. Such excitations correspond to spatio-temporal helical beams. | |||