Propagation of ultrashort intense laser pulses in a plasma Bragg grating induced by two intersecting laser pulses is studied. Such a plasma grating exhibits an ultrawide photonic band gap, near which the strong dispersion appears. It is found that the grating dispersion dominates the dispersion of the background plasma by several orders of magnitude. Particle-in-cell (PIC) simulations show the light speed reduction, pulse stretching, chirped-pulse compression, and fast compression of Bragg grating solitons in the plasma grating. The nonlinear coupled-mode theory agrees well with the PIC results. Since the plasma grating can support an ultrahigh damage threshold, it can be a novel photonic device to manipulate extremely intense femtosecond laser pulses.
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Though PBG has no thermal DT, it can be ponderomotively damaged. The given DT about a few is obtained from PIC simulations for incident laser pulses with wavelength of and duration of about a few hundred femtoseconds.
