ABSTRACT
B. M. Luther, Y. Wang, M.Berrill, D. Alessi, M.C. Marconi, M. A. Larotonda, and J.J. Rocca National Science Foundation Engineering Research Center for Extreme Ultraviolet Science and Technology, and Electrical and Computer Engineering Department, Colorado State University, Fort Collins, CO 80523
Abstract. We report the characterization of multiply ionized plasma waveguides created by a fast capillary discharge and the demonstration of guiding of laser pulses with peak intensity up to 2.2 xlO17 W/cm2 in a 5.5 cm long plasma column containing highly charged Ar ions. These discharge plasmas can reach the Ne-like or Ni-like stage of ionization for several atoms and are of interest for the generation of efficient soft x-ray lasers by longitudinal laser excitation. The guides were characterized using plasma interferometry, near and far-field imaging, and transmission measurements. A rapid discharge-driven hydrodynamic compression is observed to guide progressively lower order modes through the plasma with increasing density and degree of ionization, until the guide collapses on axis. The lowest order mode (FWHM ~50 u,m) is guided shortly before the plasma reaches the conditions for lasing in Ne-like Ar. The subsequent rapid plasma expansion forms a significantly more leaky and absorbent guide.
