Beam mutation and its suppression in Yb:YAG thin-disk regenerative amplifiers

Beam mutation in thin-disk regenerative amplifiers is proposed here, to the best of our knowledge, for the first time. It is proved to appear together with period doubling bifurcation and deterministic chaos experimentally. The suppression of beam mutation is achieved by reducing the gate length of the regenerative amplifier. With the gate length of 1.88 mu s, a Yb:YAG thin-disk regenerative amplifier with stable beam and single-energy pulse is realized. The maximum pulse energy is 145 mJ with the optical-optical efficiency of around 10 %. The repetition rate and the pulse width are 1 kHz and 580 ps respectively.