High-contrast (10), high-intensity (500 TW) J-KAREN laser system

Kiriyama, Hiromitsu; Mori, Michiaki; Nakai, Yoshiki; Shimomura, Takuya; Sasao, Hajime; Tanaka, Momoko; Ochi, Yoshihiro; Tanoue, Manabu*; Okada, Hajime; Kondo, Shuji; Kanazawa, Shuhei; Sagisaka, Akito; Daito, Izuru; Wakai, Daisuke*; Sasao, Fumitaka*; Suzuki, Masayuki; Kotaki, Hideyuki; Kondo, Kiminori; Sugiyama, Akira; Bulanov, S. V.; Bolton, P.; Daido, Hiroyuki; Kawanishi, Shunichi; Yokoyama, Atsushi

We have developed a femtosecond high intensity laser system, which combines both Ti:sapphire chirped-pulse amplification (CPA) and optical parametric chirped-pulse amplification (OPCPA) techniques, that produces more than 30 J broadband output energy, indicating the potential for achieving peak powers in excess of 500 TW. With a cleaned high-energy seeded OPCPA preamplifier as a front-end in the system, for the final compressed pulse (without pumping the booster amplifier) we found that the temporal contrast in this system exceeds 10 on the sub-nanosecond timescale, and is near 10 on the nanosecond timescale before the main femtosecond pulse. Using diffractive optical elements for beam homogenization of 100-J level high-energy Nd:glass green pump laser in a Ti:sapphire final amplifier, we have successfully generated broadband high-energy output with near-perfect top-hat intensity distributions.