Interferometric study of laser plasma at two wavelengths

Using laser interferometry at two wavelengths $\lambda=$10.64 and 0.63 $\mu m$ with high spatial and temporal resolution, a study was made of the electron concentration distribution in laser plasma. The plasma was formed when a TEA CO$_2$ laser pulse with a duration of 3 $\mu s$ and an energy per pulse of up to 3 $J$ hit the surface of a graphite target in vacuum.