By use of an imaging spectrometer we map the far-field (theta-lambda) spectra of 200-fs optical pulses that have undergone beam collapse and filamentation in a Kerr medium. By studying the evolution of the spectra with increasing input power and by using a model based on an asymptotic linear superposition of stationary wave modes (rather than the exact instantaneous solution), we are able to trace a consistent model of optical beam collapse highlighting the interplay between conical emission, multiple pulse splitting, and other effects such as spatial chirp.
© 2005 Optical Society of America
Daniele Faccio, Paolo Di Trapani, Stefano Minardi, Alberto Bramati, Francesca Bragheri, Carlo Liberale, Vittorio Degiorgio, Audrius Dubietis, and Aidas Matijosius, "Far-field spectral characterization of conical emission and filamentation in Kerr media," J. Opt. Soc. Am. B 22, 862-869 (2005)