We report guiding of sub-100-fs pulses at intensities up to 5×10<sup>15</sup> W/cm <sup>2</sup> over a distance of 1 cm in a preformed plasma channel. The width of the guided pulse was shortened, which we attribute to ionization-induced refraction at the channel entrance. A pulse energy throughput of 30% in the lowest-order was measured.
© 1997 Optical Society of America
S. P. Nikitin, T. M. Antonsen, T. R. Clark, Yuelin Li, and H. M. Milchberg, "Guing of intense femtosecond pulses in preformed plasma channels," Opt. Lett. 22, 1787-1789 (1997)