Scientists at the LOA (Laboratoire d’Optique Appliquée) in France succeeded for the first time to drive at a thousand shots per second a so-called plasma mirror in the relativistic regime (i.e., with a laser-field so strong that it hurls the plasma-electrons back and forth at nearly the speed of light.
Click here for original story, Relativistic mirror made of plasma at kilohertz repetition rate
Source: Phys.org