We introduce the Herz 10 series, a novel family of gas-based nonlinear pulse compression systems from TRUMPF Scientific Lasers, designed to shorten pulses from an industrial ultrafast laser delivering 10 mJ pulse energy at 1 kW average power. Using a gas-filled Herriott-type multi-pass cell, the system achieves significant spectral broadening that supports compression of 871 fs input pulses down to 32.5 fs at full average power. The system delivers stable, long-term operation at high pulse energy and average power while maintaining good beam quality (M² < 1.45) and an overall transmission efficiency above 90%. The Herz 10 series thus demonstrate the scalability of gas-based nonlinear pulse compression toward high-power, industrial-grade ultrashort-pulse laser systems.

Recent advances in industrial ultrashort pulse (USP) laser technology have culminated in the development of the 1 kW TruMicro Serie 9000 (Fig. 1a) [1]. Operating at sub-picosecond pulse durations, it delivers up to 10 mJ of pulse energy, enabling high-throughput material processing. Typically, USP processes require moderate fluences for efficient, high-quality outcomes [2]. Diffractive beam splitting [3] will make multi-mJ pulses at kilowatt power usable, distributing the beam into multiple spots to increase throughput significantly. Extended spot lines and dense arrays further enhance productivity by maximizing spot density for localized processing. However, large splitting angles and high spot counts can introduce spatio-temporal distortions [4], degrading beam quality and uniformity. This work shows how extreme parallelization is achieved by combining high-power USP lasers with advanced spatio-temporal compensation. We outline a path toward robust, industrial-scale ultrafast processing, emphasizing carefully optimized diffractive splitting to ensure uniformity and reproducibility at high throughput.

We report on an intensity-only and deep-learning-based method for laser beam characterization that allows to predict the underlying optical field within milliseconds. A simple near-field/far-field camera setup enables online control of adaptive optics to optimize beam quality. The robustness and precision of the method are enhanced by applying the concept of phase diversity based on spiral phase plates.

A standardized phase retrieval algorithm is presented and applied to an industry-grade high-energy ultrashort pulsed laser to uncover its spatial phase distribution. We describe in detail how to modify the well-known algorithm in order to characterize particularly strong light sources from intensity measurements only. With complete information about the optical field of the unknown light source at hand, virtual back propagation can reveal weak points in the light path such as apertures or damaged components.

We present an industrial flexible laser system utilizing fibre, rod, slab and thin-disk multipass amplifier stages to generate ultrafast pulses with 10 mJ at 1 ps or 40 mJ at 120 ps only depending on seed source.

We demonstrate ultrafast high- power laser operation, both at multi-kW average power in ultrashort-pulsed operation over extended bursts with hundreds of MHz intra-burst repetition rate from a modified TruMicro 6020 industrial laser, as well as uninterrupted, quasi-CW operation at an average power beyond 1 kW obtained with a TEM00 multipass thin-disk laser booster amplifier. The pulse repetition rate can be varied from 50 MHz to beyond 1 GHz, with single-pulse energies well above 10 mu J and single-pulse peak powers far beyond 10 MW without a post-compressor. These systems are attractive, e.g., for high-throughput materials processing or for driving nonlinear processes.

We report on the recording of the near and far field intensity beam profiles to train a convolutional neural network, which is aimed to online detect system aberrations of an ultrafast laser amplifier. We extend the state of the art by implementing a spiral phase plate to use the concept of phase diversity. It is found that the underlying optical field in amplitude and phase can be accurately revealed.

The increasing use of short – and ultrashort pulsed lasers in industrial applications leads to a demand for high power industrial-grade lasers covering a large range of pulsed laser parameters. We will present a comprehensive overview of our latest pulsed laser results based on different laser building blocks such as seed lasers, fiber amplifiers, rod and slab amplifiers, thin disk amplifiers and combinations thereof. Along with the technical insights we will give an outlook on the next development steps to further scale these parameters.

Stress-induced birefringence leads to losses in solid-state laser resonators and amplifiers with polarized output beams. A model of stress-induced birefringence in thin disks is presented, as well as measurements of stress-induced birefringence in a thin disk in a multi-kilowatt oscillator. A full-Stokes imaging polarimeter was developed to enable fast and accurate polarimetric measurements. Experimental and simulated results are in good agreement qualitatively and quantitatively and show that the polarization loss due to stress-induced birefringence is negligible for ytterbium-doped thin disks with a thickness around 100 µm but becomes relevant in thicker disks. It is concluded that stress-induced birefringence should be taken into consideration when designing a thin-disk laser system.

We present a thin-disk multipass amplifier as a power-scaling architecture for ultrafast ps and fs lasers. The system is industrially stable and supports burst functionality. Only minimal CPA is needed.

Ultrafast laser oscillators are indispensable tools for diverse applications in scientific research and industry. When the phases of the longitudinal laser cavity modes are locked, pulses as short as a few femtoseconds can be generated. As most high-power oscillators are based on narrow-bandwidth materials, the achievable duration for high-power output is usually limited. Here, we present a distributed Kerr lens mode-locked Yb:YAG thin-disk oscillator which generates sub-50 fs pulses with spectral widths far broader than the emission bandwidth of the gain medium at full width at half maximum. Simulations were also carried out, indicating good qualitative agreement with the experimental results. Our proof-of-concept study shows that this new mode-locking technique is pulse energy and average power scalable and applicable to other types of gain media, which may lead to new records in the generation of ultrashort pulses.

We report on a thin-disk laser system with more than 10 kW of output power and a beam quality of M 2 = 1.76 at an overall optical-to-optical efficiency of 51%. The system consists of two thin-disk laser oscillators and a thin-disk multi-pass amplifier system. To reach high output powers while maintaining good beam quality, the output beams of two identical laser oscillators are polarization-combined. Subsequently, the beam is amplified in a multi-pass system. To the best of our knowledge, this is the highest output power achieved for a thin-disk laser system with a beam quality close to fundamental mode.

We present a thin-disk multipass amplifier as a power scaling architecture for ultrafast lasers. 1950 W output power at a repetition rate of 800 kHz were achieved with pulses pre-compressed to 10 ps.

Ultrafast laser technology is a rapidly advancing field driven by the steadily growing demand for high average power, pulse energy and short pulse duration. All high-power (>1 kW) ultrafast lasers commonly emit in the NIR spectral range. Nonlinear processes are therefore commonly used to access the visible spectral range which offers attractive opportunities for a range of industrial and scientific applications [1] . While the average power of NIR ultrafast laser systems recently crossed the level of 10 kW [2] , so far no ultrafast laser system was reported to excess 1 kW of average power in the visible spectral range [3] , [4] . Here we present a frequency-doubled thin-disk laser delivering picosecond pulses at a wavelength of 515 nm with more than 1 kW of average power and close to diffraction-limited beam quality. The laser consists of two cascaded Yb:YAG-based thin-disk multipass amplifiers boosting the average power of a TruMicro5000-series laser. The amplified output beam was centered at a wavelength of 1030 nm, had an average power of 2050 W, a pulse energy of 6.83 mJ and $M_{x,y}^2 = 1.57/1.36$ . Subsequent frequency conversion in a type-I phase-matched 5 mm long lithium-triborate crystal with an aperture of 15x15 mm 2 enabled the generation of 1.4 kW of average power at a wavelength of 515 nm, corresponding to a SH conversion efficiency of 71%, a pulse energy of 4.87 mJ and $M_{x,y}^2 = 1.38/1.43$ . Figure 1a ) depicts the generated second-harmonic power and conversion efficiency as a function of the incident fundamental power. A measurement of the second-harmonic beams' caustic at maximum output power is shown in Fig. 1b ). Figure 1c ) shows the temporal evolution of the second-harmonic power when operated at the maximum infrared power.

We present a linear multipass amplifier based on the thin-disk technology which allows power scaling of continuous-wave, pulsed, and ultrashort-pulsed lasers without change of beam characteristics. The flexibility of the seed laser, such as choice of repetition rate, pulse duration, and bursts is maintained. Due to a large beam radius on the thin disk of several millimeters, peak intensities are lower and nonlinear effects play a smaller role compared to the competing technologies of fiber and slab amplifiers. The multipass amplifier consists of a glass-welded mirror array and a thin-disk laser head. An Ytterbium-doped thin disk with a thickness on the order of few 100 μm acts as the active medium. The mirror array is used to implement up to 36 reflections at the disk.

We present an ultrafast laser with a near-diffraction-limited beam quality delivering more than 1.4 kW of average power in the visible spectral range. The laser is based on second harmonic generation in a lithium triborate crystal of a Yb:YAG thin-disk multipass amplifier emitting more than 2 kW of average power in the infrared.

An ultrafast Yb-doped thin-disk multi-pass laser amplifier system with flexible parameters for material processing is reported. We can generate bursts consisting of four pulses at a distance of 20 ns and a total energy of 46.7 mJ at a repetition rate of 25 kHz. In single-pulse operation, 1.5 kW of average output is achieved at 400 kHz when optimizing for a beam quality of M2 = 1.5. Alignment for maximum output power provides 1.9 kW at the same repetition rate. All results are obtained without chirped-pulse amplification in the multi-pass set-up. The application potential of the system is demonstrated exploring its performance in materials processing of dielectrics. Cleaving of 3.8-mm-thick SCHOTT borofloat glass with a velocity of 1200 mm/s is demonstrated with 300 W of input power. Single-pass modification of 30 mm borosilicate glass is enabled with a Bessel beam at 1 kW of average power delivered by four-pulse bursts of an energy of 30 mJ.

An ultrafast Yb-doped thin-disk multi-pass laser amplifier system with flexible parameters for material processing is reported. We can generate bursts consisting of four pulses at a distance of 20 ns and a total energy of 46.7 mJ at a repetition rate of 25 kHz. In single-pulse operation, 1.5 kW of average output is achieved at 400 kHz when optimizing for a beam quality of M2 = 1.5. Alignment for maximum output power provides 1.9 kW at the same repetition rate. All results are obtained without chirped-pulse amplification in the multi-pass set-up. The application potential of the system is demonstrated exploring its performance in materials processing of dielectrics. Cleaving of 3.8-mm-thick SCHOTT borofloat glass with a velocity of 1200 mm/s is demonstrated with 300 W of input power. Single-pass modification of 30 mm borosilicate glass is enabled with a Bessel beam at 1 kW of average power delivered by four-pulse bursts of an energy of 30 mJ.