Ultrafast pump-probe reflectometry and Doppler spectrometry of a supercritical density
plasma layer excited by 10 17–10 18 W/cm 2 intensity, 30 fs, and 800 nm laser pulses reveal
the interplay of laser intensity contrast and inward shock wave strength. The inward shock
wave velocity increases with an increase in laser intensity contrast. This trend is supported
by simulations as well as by a separate independent experiment employing an external
prepulse to control the inward motion of the shock wave. This kind of cost-effective control of …