JAEA J-KAREN laser; High-intense, high-contrast OPCPA/Ti:sapphire laser

Kiriyama, Hiromitsu; Mori, Michiaki; Daito, Izuru; Kotaki, Hideyuki; Nakai, Yoshiki; Shimomura, Takuya*; Tanoue, Manabu*; Akutsu, Atsushi; Okada, Hajime; Motomura, Tomohiro*; Kondo, Shuji; Kanazawa, Shuhei; Nishiuchi, Mamiko; Sagisaka, Akito; Ogura, Koichi; Orimo, Satoshi; Ma, J.-L.; Yogo, Akifumi; Pirozhkov, A. S.; Kando, Masaki; Fukuda, Yuji; Chen, L. M.; Kawase, Keigo; Hayakawa, Takehito; Shizuma, Toshiyuki; Homma, Takayuki; Kameshima, Takashi; Hayashi, Yukio; Bulanov, S. V.; Daido, Hiroyuki; Kimura, Toyoaki

We report on a high-peak-power, high-contrast laser system, which combines both conventional Ti:sapphire chirped-pulse amplification and optical parametric chirped-pulse amplification (OPCPA) techniques for use in experiments where relativistic effects dominate the physics. The stretched pulses are amplified in a 3-stage Type-I Bata-Barium Borate OPCPA to an energy level of 10 mJ with an amplification gain of 10. The output pulses are then amplified in the subsequent Ti:sapphire amplifiers to an energy level of 2.9 J. Pulse compression down to 19 fs duration achieved after amplification indicates a peak power of 80 TW. The pre-pulse contrast is enhanced to better than within a few picoseconds before the main pulse. The thermal focal length of about 4 km is obtained.