We report on a multi-petawatt 3-cascaded all-optical parametric chirped-pulse amplification laser facility. The experimental results demonstrate that the maximum energy after the final amplifier and after the compressor is 168.7 J and 91.1 J, respectively. The pulse width (FWHM) is 18.6 fs in full width at half maximum after optimization of pulse compression. Therefore, 4.9 PW peak power has been achieved for the laser facility. To the best of our knowledge, this is the highest peak power reported so far for an all-optical parametric chirped-pulse amplification facility, and a compressed pulse shorter than 20 fs is achieved in a PW-class laser facility for the first time.

We report a high-intensity laser facility named Xingguang-III that generates femtosecond, picosecond, and nanosecond beams with three wavelengths, i.e. 800 nm, 1053 nm, and 527 nm, respectively. To the best of our knowledge, the laser facility is the first one which produces three beams with different pulse widths and wavelengths. An optical synchronization technique, combining super continuum generation and femtosecond optical parametric amplification, was developed to ensure three beams are from the same source to achieve precise synchronization. The femtosecond beam is a double chirped-pulseamplification Ti:sapphire laser which applies cross-polarized wave generation to improve the temporal contrast. The picosecond/nanosecond beams utilize the optical parametric amplification + Nd:glass mixed amplification scheme. The output energy and pulse width of the three beams are 20.1 J/26.8 fs, 370.2 J/0.48 ps (shortest), and 575.4 J/1.0 ns, respectively. The smallest synchronization time (peak-to-valley) and the shot-to-shot timing jitter (peak-topeak) of less than 1.32 ps have been achieved for the femtosecond and picosecond beams.

Femtosecond lasers are powerful in studying matter’s ultrafast dynamics within femtosecond to attosecond time scales. Drawing a three-dimensional (3D) topological map of the optical field of a femtosecond laser pulse including its spatiotemporal amplitude and phase distributions, allows one to predict and understand the underlying physics of light interaction with matter, whose spatially resolved transient dielectric function experiences ultrafast evolution. However, such a task is technically challenging for two reasons: first, one has to capture in single-shot and squeeze the 3D information of an optical field profile into a two-dimensional (2D) detector; second, typical detectors are only sensitive to intensity or amplitude information rather than phase. Here we have demonstrated compressed optical field topography (COFT) drawing a 3D map for an ultrafast optical field in single-shot, by combining the coded aperture snapshot spectral imaging (CASSI) technique with a global 3D phase retrieval procedure. COFT can, in single-shot, fully characterize the spatiotemporal coupling of a femtosecond laser pulse, and live stream the light-speed propagation of an air plasma ionization front, unveiling its potential applications in ultrafast sciences.

Laser amplification in plasma, including stimulated Raman scattering amplification and strongly coupled stimulated Brillouin scattering (sc-SBS) amplification, is very promising to generate ultrahigh-power and ultrashort laser pulses. But both are quite complex in experiments: at least three different laser pulses must be prepared; temporal delay and spatial overlap of these three pulses are difficult. We propose a single pulse compression scheme based on sc-SBS in plasma. Only one moderately long laser is applied, the front part of which ionizes the gas to produced plasma, and gets reflected by a plasma mirror at the end of the gas channel. The reflected front quickly depletes the remaining part of the laser by sc-SBS in the self-similar regime. The output laser is much stronger and shorter. This scheme is at first considered theoretically, then validated by using 1D PIC simulations.

In a tiled-grating system, it is difficult to make two tiled gratings strictly coplanar. We propose and demonstrate for the first time, as far as we know, a simple method by which the longitudinal piston error between two tiled gratings can be reduced below lambda/10, close to the influence of the environmental factors. The alignment precision of the method increases with the tiled-grating system's stability to environmental factors.