Design and implementation of a TW-class high-average power lasersystem

摘要

We describe the design, modeling and characterization of antitanium-doped sapphire multipass, kilohertz amplifier system withnoutput pulses of energy 4.4 mJ and duration 17 fs, giving a peak powernof 0.26 TW. The thermal lensing in the second amplifier stage isnvirtually eliminated by cryogenic cooling of the laser crystal.nGain-narrowing and shifting of the amplified spectrum are reduced byntailoring the output spectrum of the oscillator and by using a low-lossnmultipass amplifier chain. Fourth-order spectral dispersion wasncompletely eliminated by using a prism pair in addition to adjusting thenstretcher and compressor grating separation and angle. We alsonnumerically modeled the evolution of the pulse energy and spectral phasenand amplitude through the amplifier system. The results of the model arenin excellent agreement with measurements made using the technique ofntransient-grating frequency-resolved optical gating