High average power picosecond Yb:YAG thin-disk lasers are being developed at Hilase. A compact 1 mJ/100 kHz and 4 mJ/100 kHz zero-phonon-line-pumped regenerative amplifiers PERLA C with a CVBG compressor provide <2 ps long pulses in a nearly diffraction-limited beam. The output was successfully converted to 2nd and 4th harmonic frequency with high conversion efficiency. High energy, QCW-pumped beamline PERLA B is operated at 45mJ/1kHz in fundamental spatial mode and pulse length < 2ps. Its second stage amplifier is being assembled and 1.8 J was extracted. The latest development status of all thin-disk beamlines at the Hilase center is reported.
An overview of Czech national R&D project HiLASE (High average power pulsed LASEr) is presented. The HiLASE project aims at development of pulsed DPSSL for hi-tech industrial applications. HiLASE will be a user oriented facility with several laser systems with output parameters ranging from a few picosecond pulses with energy of 5 mJ to 0.5 J and repetition rate of 1-100 kHz (based on thin disk technology) to systems with 100 J output energy in nanosecond pulses with repetition rate of 10 Hz (based on multi-slab technology).
The mid-IR wavelength range has gained increased interest due to its applications in gas sensing, medicine, defense, and others. Optical parametric devices play an important role in the generation of radiation in the mid-IR. Low thermal load of nonlinear crystals promises high average power outputs if powerful pump laser is available. We have developed 75-W average power pump laser operating at 100 kHz repetition rate. The pulses of Yb-fiber laser oscillator at 1030-nm wavelength are stretched by a chirped volume Bragg grating from 5 ps to 180 ps and inserted into a cavity of regenerative amplifier with an Yb:YAG thin-disk. The amplified pulses are compressed by a chirped volume Bragg grating with an 88% efficiency. We have proposed a wavelength conversion system generating picosecond pulses tunable between 2 and 3 μm. The seed signal radiation is acquired by the optical parametric generation in the first nonlinear crystal. Signal pulse energy is increased in the subsequent optical parametric amplifiers. Each amplification stage consists of a crystal pair in the walkoff compensating arrangement. The wavelength of the signal beam is tunable between 1.6 and 2.1 μm. The 2.1 - 3 μm tunable source will be the idler beam taken from the last amplification stage. Calculations show the output power of ten watt can be achieved for 100 W pump. The results of preliminary experiments with seeded optical parametric generation and subsequent amplification are presented and discussed.
Amplification of femtosecond pulses using an ultra-narrowband gaseous pulse laser was demonstrated for the first time.
A single-shot sub-nanosecond iodine photodissociation laser with a bandwidth of 20 pm was used as a driver in an allstage
OPCPA. An externally triggerable OPO tuned to laser line of 1315.24 nm was used in the front end of the iodine
laser. Frequency tripled beam at 438 nm was used to pump parametric amplifiers, LBO and KDP crystals. The signal
pulses from a Ti:sapphire laser at the central wavelength of 800 nm with a bandwidth of 70 nm (FWHM) were stretched
from 12.5 fs to 250 ps and amplified by a factor of 2×108. The amplified pulses of typical bandwidth of 50 nm were
compressed down to 27 fs. The output power of 0.5 TW was achieved. An optimized amplifier chain and addition of a
third nonlinear crystal would enable to generate femtosecond pulses of several terawatts. The broadband pulses at 800 nm
central wavelength were amplified in the KDP crystal for the first time, due to the suitable wavelength of the pump
pulses. Availability of large aperture KDP crystals promises the generation of petawatt beam at kJ iodine laser facilities.