Abstract
Nanosecond-level pulses of specific shape is usually generated by stacking chirped pulses for high-power inertial
confinement fusion driver, in which nonlinear imaging of scatterers may damage precious optical elements. We present a
numerical study of the characteristics of nonlinear imaging of scatterers in broadband laser stacked by chirped pulses to
disclose the dependence of location and intensity of images on the parameters of the stacked pulse. It is shown that, for
sub-nanosecond long sub-pulses with chirp or transform-limited sub-pulses, the time-mean intensity and location of
images through normally dispersive and anomalously dispersive self-focusing medium slab are almost identical; While
for picosecond-level short sub-pulses with chirp, the time-mean intensity of images for weak normal dispersion is
slightly higher than that for weak anomalous dispersion through a thin nonlinear slab; the result is opposite to that for
strong dispersion in a thick nonlinear slab; Furthermore, for given time delay between neighboring sub-pulses, the
time-mean intensity of images varies periodically with chirp of the sub-pulse increasing; for a given pulse width of
sub-pulse, the time-mean intensity of images decreases with the time delay between neighboring sub-pulses increasing;
additionally, there is a little difference in the time-mean intensity of images of the laser stacked by different numbers of
sub-pulses. Finally, the obtained results are also given physical explanations.
