Fast switchable CW to ultrashort pulsed high-power laser beam from a single thin-disk multipass amplifier

To open up new opportunities in laser material processing, combining multiple processes in parallel or fast sequence schemes is a promising concept. A single laser source with dynamic and flexible operation modes is highly demanded for these tasks. In this contribution, we will present a versatile laser system which is the first step toward the Universal Laser Machine capable of being used for a broad range of laser-based manufacturing tasks. The laser system presented here consists of a single thin-disk multipass amplifier capable of sequentially or simultaneously amplifying both Continuous Wave (CW) and Ultra-Short Pulsed (USP) laser radiation and delivering kW-class average output power. The approach uses a polarization-multiplexing scheme to amplify two seeds (CW and sub-10 picoseconds) within a common amplifier. This allows for the generation of a single, nearly diffraction-limited output beam composed of CW or USP or both CW and USP radiation at a wavelength of 1030 nm. High versatility of the system is achieved by the implementation of multiple acousto-optic modulators, which enables fast (on a microsecond timescale) switching capabilities between different powers and operation modes. A quick change between the operation state of sole CW, sole USP, and combined output radiation with arbitrary power ratio can thus be realized. Furthermore, our system includes the possibility of a seamless adjustment of the absolute average output power values of each CW and USP fraction of the generated beam.