In-house beam-splitting pulse compressor for high-energy petawatt lasers

Abstract

One of the most serious bottleneck on achieving kilojoule-level high-energy petawatt (PW) to hundreds-petawatt (100PW) lasers with ps to fs pulse duration is the requirement of as large as meter-sized gratings in the compressor so as to avoid the laser-induced damage to the gratings. However, this kind of meter-sized grating with high quality is hard to manufacture so far. Here, we propose a new in-house beam-splitting compressor based on the property that the damage threshold of gratings depend on the pulse duration. The new scheme will simultaneously improve the stability, save expensive gratings, and simplify the size of compressor because the split beams share the first two parallel gratings. Furthermore, based on the fact that the transmitted wavefront of a glass plate can be much better and more precisely controlled than that of the diffraction wavefront of a large grating, then glass plates with designed transmitted wavefront are proposed to compensate the wavefront distortion introduced by the second, the third gratings, and other optics in-house such as the beam splitter. This simple and economical method can compensate the space-time distortion in the compressor and then improve the focal intensity, which otherwise cannot be compensated by the deformable mirror outside the compressor due to angular chirp. Together with multi-beams tiled-aperture combining scheme, the novel compressor provides a new scheme to achieve highenergy PW-100PW lasers or even exawatt lasers with relatively small gratings in the future.

Multistep pulse compressor for 10s to 100s PW lasers

“…Therefore, if we can reduce the spatial intensity modulation of the input laser beam, we can increase the maximum input pulse energy for the main FGC. Inspired by our previous "in-house beam-splitting compressor" work, in which the beam profile after the first pair of gratings is excellently smoothed in comparison to that of the input laser beam with strong spatial intensity modulation [23]. The beam smoothing effect is owing to the spatial dispersion of the laser beam by the grating pair.…”

“…Recently, a novel "in-house beam-splitting compressor" design has been proposed to reduce the beam combing challenge for 10s to 100s PW lasers [23]. In comparison to the XCELS-200PW, the ELI-200PW, and the former SEL-100PW designs, in which the beam splitters were located before the amplifier or before the compressor, respectively, the beam splitter in this new "in-house beam-splitting compressor" is moved backward into the compressor, which is located between the second grating and the third grating of a typical FGC.…”

“…As a result, we can find resolutions from shaping or modifying the spatiotemporal properties of the input and output laser beams. In the previous "in-house beam-splitting compressor", the property that laser-induced damage threshold of gratings decreases with the shortening of pulse duration was passively used [23]. Here, through actively modifying both the temporal and the spatial properties of the input and output laser beams on the surface of the first and the last gratings, respectively, it is possible to improve the maximum input and output pulse energy in the FGC.…”

“…These two parallel grating pairs are mirroring each other. Here, a compensating plate (CP) is used to compensate the diffraction wavefront errors of grating G2 and grating G3 [23]. The CP can also be used to compensate the negative spectral dispersion induced by the prism pair in the pre-compressor.…”

A Survey of Spatio-Temporal Couplings throughout High-Power Ultrashort Lasers

“…Yet, this provides for the first time a glimpse of the full spatio-temporal properties of high-power ultrashort laser pulses while they are being produced, and illustrates the potential of applying the latest generation of ultrafast diagnostics not only at the output of but also inside ultrashort laser systems. We hope that this will help open new trends in the development, control and optimization of ultrashort light sources-especially the most sophisticated ones, such as Optical Parametric Chirped-pulse Amplification [14], Frequency-domain Optical Parametric Amplification systems [15], systems with coherent combination [16,17], compressors based on tiled gratings [18][19][20], or even more exotic scenarios to go beyond the Petawatt power range in future generations [21]. Fig.…”