Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900
Funds: Supported by the National Natural Science Foundation of China under Grant No 61377102, and the Defense Industrial Technology Development Program under Grant No B1520133010.
Based on the frequency-to-time mapping relation of the linearly chirped pulse, the temporal phase shift induced by a laser-excited wake in a helium gas jet is measured using a chirped-pulse spectral interferometry with 140 fs resolution over a temporal region of 1 ps in a single shot. In this measurement, the image of the wake is obtained with one-dimensional spatial resolution and temporal resolution limited only by the bandwidth and chirp of the pulse. The 'bubbles' feature of the wake structure, along with multiple wakes excited by the main lobe and the side lobe of a laser focal-spot, is captured simultaneously.
Hideyuki K, Masaki K, Takatsugu O, Shinichi M, James K K, Shuji K, Shuhei K, Takashi Y, Toru M and Kazuhisa N 2002 Phys. Plasmas 9 1392 doi: 10.1063/1.1457464