Subexawatt few-cycle lightwave generation via multipetawatt pulse compression

We identify the physical scenarios of nonlinear spatiotemporal dynamics of extreme-power laser fields enabling compression of a broad-beam ultrafast multipetawatt laser output to subexawatt few-cycle light pulses focusable to pulse intensities up to 1025 W/cm2. We show that, with a careful control over the key limiting physical effects, which include dispersion, pulse self-steepening, small-scale self-focusing, and ionization effects, enhanced self-phase modulation of multipetawatt laser waveforms in a solid medium can provide spectral bandwidths compressible to few-cycle pulse widths with output beam profiles focusable to ultrarelativistic intensities.