Dataset for Spatio-temporal dynamics in the near-field of mosaic grating compressors with different pulse durations for kilojoule petawatt laser system

In the kilojoule petawatt laser systems, laser-induced damage of meter-sized compression gratings has become the bottleneck limiting output performance. The optical mosaic is a mature approach for meter-sized grating fabrication, but the diffraction of mosaic gaps would increase damage risks of the final grating. As the grating damage exhibits strong dependence on electric field and pulse duration, here, under the cases of Fourier-transform-limited (FTL) pulse and the 10ps pulse for physical applications, the 3D dynamics in the near-field of symmetric and asymmetric compressors employing mosaic gratings are investigated. For the FTL pulse, when the diffraction patterns originating from gaps of the upstream gratings exhibit frequency dependence, the resulting near-field intensity fluctuations at the last grating can be effectively smoothed out. The effect from the first grating gap in symmetric compressor is exceptional. For the 10ps pulse, when the single upstream grating possesses a gap, the near-field intensity fluctuations remain unsmoothed regardless of its frequency dependence at the final grating. Notably, the instantaneous intensity fluctuations become significantly deteriorated while gaps exist in all upstream gratings. The results offer a crucial guidance for the configuration optimization and safe operation of the compressor.