The laser system is based on an Yb:YAG thin-disk regenerative amplifier, which is operated in different operation modes
in order to address broad spectrum of pulse durations. It is especially interesting for application development tasks, when
different pulse durations can be tested to find the application optimum. For sub-picosecond pulse duration the dispersion
of the regenerative amplifier output is compensated with a pair of diffraction gratings. Pulses with a full width at half
maximum of 334 fs at an output power level of 30 W can be produced using a nonlinear spectrum broadening during
amplification. Tuning of the distance between gratings or abandoning of the compressor allows for output pulse
durations of several picoseconds with an output power of 60 W. A second seed source allows for pulse durations up to
several nanoseconds. Further, the amplifier was operated in cavity-dumped or in Q-switched mode just by changing of
the electrical control of the Pockels cell in the amplifier. The pulse durations range is extended, correspondingly, to 100
ns and even to microseconds.
A thin disk regenerative amplifier based on Yb:KLW (potassium lutetium tungstate) is operated in different set-ups,
changing the net gain and total amount of nonlinearity during amplification. Spectrum broadening during amplification
produces Lorentz-shaped pulses with an autocorrelation width of 190 fs after dispersion compenstaion. Damping of
bifurcations is demonstrated by nonlinear spectrum broadening, allowing stable operation with an output energy of of
nearly 400 μJ at 50 kHz.
Advanced pulsed thin disk laser sources based on several pulse generation schemes, including regenerative amplification
as well as cavity-dumping, will be presented. These sources are able to produce pulse energies in the multi-millijoule
range at repetition rates of up to several 100 kHz, resulting in average output powers in excess of 100 W. Also the
efficient intra-cavity frequency conversion of these sources will be discussed.