Experimental study of the first-order spatiotemporal couplings effect in laser plasma accelerators*

Laser plasma accelerators can produce electron beams with energies of multi GeV level [1], which attracts a variety of applications including high-energy physics and drivers for light sources. However, the beam quality has to be improved for most applications. Among parameters to affect beam quality, spatiotemporal couplings (STCs) of the laser pulse can be an important effect. With the first-order STCs [2], laser pulse can have pulse front tilt (PFT), which exhibits dynamic behavior near focus [3]. We have investigated the effect of PFT on electron beam steering experimentally using the BELLA petawatt laser  at the Lawrence Berkeley National Lab. While previous studies were focused on the near-field angular dispersion effect [4], we show for the first time the effect of temporal chirp combined with the near-field angular dispersion.

[1] W. Leemans et al., PRL 113 (2014) 245002.

 [2] S. Akturk et al., Opt. Exp., 13 (2005) 8642.

 [3] K. Nakamura et al., IEEE J. Quantm. Electron. 53 (2017) 1200121.

[4] A. Popp et al., PRL 105 (2010) 215001.