Guiding of high-intensity laser pulses with a hydrogen-filled capillary discharge waveguide

We report guiding of laser pulses with peak input intensities greater than 10(17) W cm(-2) in 30 mm and 50 mm long H-2-filled capillary discharge waveguides. Under conditions producing good guiding the coupling and propagation losses of the waveguide were <4% and (7+/-1) m(-1), respectively. The spectra of the transmitted pulses were not broadened significantly, but were shifted to shorter wavelength. It is concluded that this shift is not associated with significant temporal distortion of the laser pulse.