Interplay of diffraction and nonlinear effects in the propagation of ultrashort pulses

Research output: Contribution to journalArticle

8 Citations (Scopus)


We investigate the interplay of diffraction and nonlinear effects during the propagation of very short light pulses. Adapting the factorization approach to the problem at hand by keeping the transverse-derivative terms apart from the residual nonlinear contributions we derive an unidirectional propagation equation which is valid for weak dispersion and reduces to the slowly-evolving-wave-approximation in the case of paraxial rays. A comparison of the numerical simulation results for the two equations shows pronounced differences when self-focusing plays an important role. We devote special attention to modelling the propagation of ultrashort terahertz pulses taking into account diffraction as well as Kerr-type and second-order nonlinearities. Comparing the measured and simulated wave forms we deduce the value of the nonlinear refractive index of lithium niobate in the terahertz region to be three orders of magnitude larger than in the visible part of the spectrum.

Original languageEnglish
Article number035401
JournalJournal of Physics B: Atomic, Molecular and Optical Physics
Issue number3
Publication statusPublished - Jan 8 2016



  • Kerr effect
  • diffraction
  • nonlinear propagation

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Condensed Matter Physics

Cite this