Observation of relativistic and charge-displacement self-channeling of intense subpicosecond ultraviolet (248 nm) radiation in plasmas

Experimental studies examining a anew relativistic regime of high-intensity short-pulse propagation in plasmas have been performed which present evidence for the formation of a stable mode of spatially confined (channeled) propagation. For an electron density of \ensuremath{\sim}1.35\ifmmode\times\else\texttimes\fi{}${10}^{21}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$ and a power of \ensuremath{\sim}3\ifmmode\times\else\texttimes\fi{}${10}^{11}$ W, the results indicate a channel radius ,1 \ensuremath{\mu}m and a peak intensity \ensuremath{\sim}${10}^{19}$ W ${\mathrm{cm}}^{2}$. Comparison of these findings with a dynamical theory yields agreement for both the longitudinal structure and the radial extent of the propagation observed.