Biomedical subjects

Tomás Dohnal

Publications and source records attributed to Tomás Dohnal.

2 recordsLinked to original sources

PubMed2006

Finite-dimensional model for defect-trapped light in planar periodic nonlinear structures.

We study the dynamics of 2D gap solitons (GSs) in Bragg resonant nonlinear (photonic) gratings in the presence of localized defects. Previous work [Stud. Appl. Math.115, 209 (2005)] explains the mechanism of trapping the GS-carried energy at a defect via a resonant energy transfer from the GS into defect modes. We derive a finite-dimensional model that describes the evolution of the defect-trapped state as an interaction of linear defect modes and show that this model approximates the full dynamics very well in the regime when moderate amounts of GS energy are trapped.

Journal Article↗

PubMed2005

Effects of dissipative disorder on front formation in pattern forming systems.

We study the effects of weak disorder in the linear gain coefficient on front formation in pattern forming systems described by the cubic-quintic nonlinear Schrödinger equation. We calculate the statistics of the front amplitude and position. We show that the distribution of the front amplitude has a loglognormal diverging form at the maximum possible amplitude and that the distribution of the front position has a lognormal tail. The theory is in good agreement with our numerical simulations. We show that these results are valid for other types of dissipative disorder and relate the loglognormal divergence of the amplitude distribution to the form of the emerging front tail.

Journal Article↗