Broadband high power laser based on optical parametric chirped pulse amplifier

Summary form only given. We have been developing a broadband high-gain laser system by using optical parametric chirped pulse amplifiers. The laser system consists of a Ti:sapphire oscillator, a pulse stretcher, two LBO amplifying stages with crystal length of 18 mm and 15 mm respectively, a final KDP amplifying stage, a high-power Nd:YAG-Nd:glass pump source and a pulse compressor. The signal with a pulse duration of 120 fs at 1.064 /spl mu/m was derived from the Mirra 900 Ti:sapphire oscillator. The pulse was temporally expanded to about 500 ps in a grating pair stretcher and then was divided into two parts by a beam splitter. A fraction of the chirped pulse was used as the seed of the pump source. Another fraction acted as the seed of the OPCPA stages. Since the OPCPA stages and the pump source used the same oscillator, the jitter between signal and pump reduced to less than 5 ps, which improved significantly the output energy stability and reduced the aberration of the output spectrum.