We present a theoretical investigation of the self-focusing dynamics of femtosecond pulses in a hollow waveguide. We show that transverse effects play an important role in these dynamics, even for pulses that are significantly below the critical power for self-focusing in free space, and that excitation of higher-order modes of the waveguide results in the spreading of the pulse in time. Inclusion of self-steepening and space–time focusing in our model is necessary for properly capturing the pulse dynamics.
© 2000 Optical Society of America
(230.7370) Optical devices : Waveguides
(260.5950) Physical optics : Self-focusing
(270.5530) Quantum optics : Pulse propagation and temporal solitons
(320.7110) Ultrafast optics : Ultrafast nonlinear optics
D. Homoelle and Alexander L. Gaeta, "Nonlinear propagation dynamics of an ultrashort pulse in a hollow waveguide," Opt. Lett. 25, 761-763 (2000)