Multistep pulse compressor for 10s to 100s PW lasers

Abstract

High-energy tens (10s) to hundreds (100s) petawatt (PW) lasers are key tools for exploring frontier fundamental researches such as strong-field quantum electrodynamics (QED), and the generation of positron-electron pair from vacuum. Recently, pulse compressor became the main obstacle on achieving higher peak power due to the limitation of damage threshold and size of diffraction gratings. Here, we propose a feasible multistep pulse compressor (MPC) to increase the maximum bearable input and output pulse energies through modifying their spatiotemporal properties. Typically, the new MPC including a prism pair for pre-compression, a four-grating compressor (FGC) for main compression, and a spatiotemporal focusing based self-compressor for post-compression. The prism pair can induce spatial dispersion to smooth and enlarge the laser beam, which increase the maximum input and output pulse energies. As a result, as high as 100 PW laser with single beam or more than 150 PW through combining two beams can be obtained by using MPC and current available optics. This new optical design will simplify the compressor, improve the stability, and save expensive gratings/optics simultaneously. Together with the multi-beam tiled-aperture combining method, the tiled-grating method, larger gratings, or negative chirp pulse based self-compression method, several 100s PW laser beam is expected to be obtained by using this MPC method in the future, which will further extend the ultra-intense laser physics research fields.

Further Development of the Short‐Pulse Petawatt Laser: Trends, Technologies, and Bottlenecks

“…Another possible solution is to use two matched gratings or deformable gratings as the second and the third gratings in the main compressor to compensate each other; [ 360 ] or to introduce a wavefront‐correction plate or a deformable mirror in the main compressor (between the second and the third gratings) to correct the overlaid wavefront of the second and the third gratings. [ 284,361 ] In our opinion, this complex spatiotemporal distortion in technology is not a fatal problem for the next‐generation short‐pulse PW laser, although it now becomes more and more serious in current short‐pulse PW lasers, especially in high average‐power TW/PW lasers.…”

“…That is why kinds of technologies for beam smoothing and spatial noise (spatial frequency) filtering have been widely used in almost all nanosecond, picosecond, and femtosecond high-energy lasers. [279][280][281][282][283][284][285][286] Even in air/vacuum, Figure 19f,g shows a simulation result: after 2 m long free propagation, diffraction also degrades both the intensity and wavefront profiles and leads to energy lost. Here, based on a 300 nm (700-1000 nm) broadband intense laser pulsed beam, the simulation shows that SSSF has limited spectral dependence due to a short interaction length in media (see Figure 19d,e), while long-distance free propagation in air/vacuum introduces obvious spatiospectral coupling (accordingly spatiotemporal coupling) in both amplitude (intensity) and phase (wavefront) (see Figure 19f,g).…”

Beam Smoothing Based on Prism Pair for Multistep Pulse Compressor in PW Lasers

“…These problems can be solved in the whole system design in Ref. [15] by a reflective deformable mirror (DM). Actually, the induced spatial dispersion width is small in comparison to the beam size, and the transmitted light owning small wavefront distortion.…”

“…Recently, it was reported that this spatiotemporal focusing can be used in ultrahighpeak-power laser systems with large beam sizes [20][21][22][23]. In this MPC optical design, the intentionally induced spatial dispersion using a grating or prism pair was used to smoothen the laser beam with large beam sizes to reduce its LSIMR [15].…”

“…Recently, a novel optical design called a multistep pulse compressor (MPC) was proposed to increase the input/output pulse energy of grating-based pulse compressors [15]. With the MPC method, beam smoothing based on prism pairs is an important process that is used as the pre-compressor step.…”