Small-scale Self-focusing of High Power Periodic Chirped Pulses with Applied Angular Dispersion
W-Y. Cheng, X-M. Zhang and J-Q. Su
In inertial confinement fusion, an efficient far-field-smoothing method is periodic chirped pulse (PCP) with applied angular dispersion. In this paper, small-scale self-focusing of angularly dispersed PCP in near field is studied numerically. The results indicate self-focusing of angularly dispersed PCP grows intensely after nonlinear propagation a distance in near field. By tracing the motion of self-focusing focal points depending on time, it is found angularly dispersed PCP is a motion beam in transverse space. If an optimum colour cycle is employed, instantaneous peak intensity and peak of time-average intensity of a spatial focal spot will be suppressed, which will prevent the amplifier medium to be damaged in a way.
Keywords: Periodic chirped pulse, angular dispersion, nonlinear propagation, small-scale self-focusing, motion beam, inertial confinement fusion