Demonstration of a high spatiotempral-quality petawatt-class Ti:sapphire CPA laser system

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

OPCPA (Optical parametric chirped-pulse amplification) operation with low gain by seeding with high energy, clean pulses is shown to significantly improve the contrast to better than 10-10 in a high intensity Ti:sapphire laser system that is based on chirped pulse amplification. In addition to the high contrast broadband high energy output from the final amplifier is achieved with a flat-topped spatial profile of filling factor near 77 %. This is the result of pump beam spatial profile homogenization with diffractive optical elements. Final pulse energies exceed 30 Joules indicating capability for reaching peak powers in excess of 500-TW.