An overview of the latest developments of kilowatt-level diode pumped solid state lasers for advanced applications at the HiLASE Centre is presented. An overview of subcontracted and in-house-developed laser beamlines is presented. The aim of development is to build kW-class beamlines delivering picosecond pulses between 1- and 100-kHz repetition rates and high-energy nanosecond pulses at 10 Hz. The picosecond beamlines are based on Yb:YAG thin-disk amplifiers and chirped pulse amplification. The current status of the beamlines’ performance is reported. The advantages of zero-phonon line and pulsed pumping are demonstrated with respect to efficiency, thin disk temperature and beam quality. New diagnostics methods supporting the high average power lasers’ development, such as the high-resolution spectroscopy of Yb-doped materials, in situ thin disk deformation measurements, single-shot M² measurement, realization of wavefront correction by a deformable mirror and the laser performance of a new mixed garnet ceramics, are described. The energetic, thermal and fluid-mechanical numerical modeling for the optimization of the multi-slab amplifiers is also described.

The development of kW-class diode-pumped picosecond laser sources emitting at various wavelengths started at the HiLASE Center four years ago. A 500-W Perla C thin-disk laser with a diffraction limited beam and repetition rate of 50–100 kHz, a frequency conversion to mid-infrared (mid-IR), and second to fifth harmonic frequencies was demonstrated. We present an updated review on the progress in the development of compact picosecond and femtosecond high average power radiation sources covering the ultraviolet (UV) to mid-IR spectral range at the HiLASE Center. We also report on thin-disk manufacturing by atomic diffusion bonding, which is a crucial technology for future high-power laser development.

Laser treatment of amorphous TiO ₂ nanotube layers leads to their crystallization without deformation or formation of the thermal oxide layer.

We report new observations on picosecond deep ultraviolet coherent beams generated in a CLBO as the fourth and fifth harmonics of a diode pumped high average power Yb:YAG thin disk laser operating at 77 kHz repetition rate at 1030 nm. The effects of the two-photon absorption were observed, e.g. the modification of phase matching conditions, lowering of the conversion efficiency. The fifth harmonic generation (4ω+1ω) was studied for different time delays between both pump beams and for the case of excess input power of the fundamental. The latter effect suggests a possibility of increasing DUV output at short crystals. The highest output power obtained at 257 nm was 7.6 W and 1 W at 206 nm. To our knowledge these DUV output powers rank among the highest for picosecond pulses at the repetition rate of the order of magnitude of 100 kHz.

The Verdet constant dispersion of CeF 3 crystal was measured in the spectral range from 0.45 to 1.95 μ m . To the best of our knowledge, CeF 3 crystal was investigated for the first time as a potential material candidate for near-infrared Faraday rotators (FRs). The experimental results obtained for Verdet constant dispersion were compared to other magneto-optical materials with the conclusion that CeF 3 crystal possesses up to 60% higher Verdet constant in the near-infrared spectral region 1.1 to 1.5 μ m compared to widely used terbium gallium garnet crystal. Furthermore, the presented experimental setup is capable of high precision measurement of Verdet constant dispersion in a broad spectral range, with measurement error not exceeding 5%, therefore, representing a powerful tool for FRs development.