Laser Requirements for High-Order Harmonic Generation by Relativistic Plasma Singularities

Alexander Pirozhkov, Timur Esirkepov, Tatiana Pikuz, Anatoly Faenov, Akito Sagisaka, Koichi Ogura, Yukio Hayashi, Hideyuki Kotaki, Eugene Ragozin, David Neely, James Koga, Yuji Fukuda (+10 others)
2018 Quantum Beam Science  
We discuss requirements on relativistic-irradiance (I 0 > 10 18 W/cm 2 ) high-power (multi-terawatt) ultrashort (femtosecond) lasers for efficient generation of high-order harmonics in gas jet targets in a new regime discovered recently . Here, we present the results of several experimental campaigns performed with different irradiances, analyse the obtained results and derive the required laser parameters. In particular, we found that the root mean square (RMS) wavefront error should be
more » ... or should be smaller than~100 nm (~λ/8). Further, the angular dispersion should be kept considerably smaller than the diffraction divergence, i.e., µrad level for 100-300-mm beam diameters. The corresponding angular chirp should not exceed 10 −2 µrad/nm for a 40-nm bandwidth. We show the status of the J-KAREN-P laser (Kiriyama et al., 2015; Pirozhkov et al., 2017) and report on the progress towards satisfying these requirements.
doi:10.3390/qubs2010007 fatcat:hajlbeamq5dt7iyjpo3wbchagy