Recent progress and future prospects of high-energy peta-watt laser in LFRC, CAEP

Abstract

The laser system with output energy larger than 150 Joules, output pulse width less than 1-ps has been finished in last year in Research Center of Laser Fusion (LFRC) at China Academy of Engineering Physics (CAEP). The front-end of the system can emit 4-mJ, 1053-nm femtosecond laser by optical parametric amplification based on supercontinuum white-light injection. Then the laser is stretched to chirped pulse with 2ns pulse duration and amplified to near 200 Joules by multi-stage phosphate Nd:glass amplifiers. Subsequent amplification in a chirped-pulse amplification (CPA) chain will result in a sometimes substantial lengthening of the output pulses owing to gain narrowing and uncompensated phase errors. The acousto-optic programmable dispersive filter (AOPDF) [2] is used to modulate the amplitude and phase of ultrashort pulses in order to maintain the short pulse duration after amplification. The size of a single gratings is not enough for high energy pulse compression, Therefore we developed tiled-gratings technology. A single-pass tiled-gratings-compressor (TGC) [3] is used in this system. Real-time monitoring and on-line alignment system has been established to achieve coherent addition of the tiled gratings. Impact of vibration being eliminated to a least level, the tiled gratings can keep stable for a several hours.