We show that the angle-wavelength spectra of light filaments excited by ultrashort pulses experience a transition from X- to O-like structures when their carrier wavelengths are switched from normal to anomalous dispersion. Calculations confirm that the O-shaped conical emission follows the elliptic geometry of the nonlinear Schrödinger equation with anomalous dispersion.
© 2005 Optical Society of America
Miguel A. Porras, Audrius Dubietis, Ernestas Kucinskas, Francesca Bragheri, Vittorio Degiorgio, Arnaud Couairon, Daniele Faccio, and Paolo Di Trapani, "From X- to O-shaped spatiotemporal spectra of light filaments in water," Opt. Lett. 30, 3398-3400 (2005)