Chirped pulse shadowgraphy for single shot time resolved plasma expansion measurements

The dynamics of ultrashort laser plasmas demand single shot temporal measurements on fast time scales. We describe a method to record the plasma expansion on picosecond (ps) timescales continuously over hundreds of ps, in single shot. The method uses the chirp of a Ti:sapphire laser as a time-resolved optical diagnostic tool. Using this technique, the evolution of the plasma expansion had been recorded with ps time resolutions, by probing with a chirped laser pulse of 200 ps duration. A peak expansion velocity of 1.8×107 cm/s is observed and its evolution in time is obtained for ∼300 ps.