A 100-PW compressor based on single-pass single-grating pair

Abstract

A multistep pulse compressor (MPC) based on a single-pass single-grating-pair (SSGP) is proposed to simplify the entire multi-petawatt (PW) compressor. Only one grating pair with relatively long perpendicular distance is used to generate the same amount of spectral chirp compared with a fourgrating main compressor. As SSGP compressor induces the largest spatial chirp, it can introduce the best beam-smoothing effect to the laser beam on the last grating. When considering the diffraction loss of only two gratings, the total compression efficiency of the SSGP compressor is even larger than that of a four-grating main compressor. Furthermore, the wavefront aberration induced by SSGP compressor can be better compensated by using deformable mirrors, however it is difficult or complicated to be well compensated in a four-grating compressor. Approximately 50-100 PW laser pulses can be obtained using this SSGP-based multistage-smoothing MPC with a single laser beam.

Reducing laser beam fluence and intensity fluctuations in symmetric and asymmetric compressors

“…According to the contrary assertion made in Ref. [25], the integrated contrast does not degrade, which is evidently due to the neglect of the space-time coupling effects considered above.…”

“…This is the difference between the AFGC and the TC. A compressor with a single-grating pair (single-pass single-grating pair (SSGC)) [ 25 ] is a particular case of an AFGC with .…”

“…It is obvious that the compressor, in which the beam passes a considerable distance, is also a fluence fluctuation filter, but the properties of this filter have not been studied before. Moreover, to smooth fluence fluctuations it was recently proposed to use a pair of prisms [ 23 ] and an asymmetric four-grating compressor (AFGC) [ 24 ] , as well as a compressor with one pair of gratings [ 25 , 26 ] , which is a particular case of the AFGC. Numerical simulations were carried out in Refs.…”

“…Note that sometimes (see, e.g., Ref. [25]), instead of Equation (34) it is assumed that , where is the path length from A1 to C1, which contradicts Equation (34). Taking into account that from Equations (34) and (35) to an accuracy of , we obtain the following: The second pair of gratings from point A2 to point C2 is equivalent to the first pair from point A1 to C1 accurate to the replacement of by or by , since for increases but decreases, which is well-described in Figure 1.…”

“…Note that sometimes (see, e.g., Ref. [25]), instead of Equation (34) it is assumed that , where is the path length from A1 to C1, which contradicts Equation (34). Taking into account that from Equations (34) and (35) to an accuracy of , we obtain the following: …”