High-energy diode-pumped D_2O-cooled multislab Yb:YAG and Yb:QX-glass lasers

Abstract

We investigated the lasing performance of a multislab Yb:QX and Yb:YAG laser amplifiers using a facet-cooled design. Di-deuterium oxide (D2O) was used as the coolant flowing between the active slabs with the pump and laser light passing through the very low absorbing heavy-water films. A square pump profile at a maximum intensity of 40 kW/cm2 drove the amplifier with a peak fluence of 5.5 J/cm2 and a pulse duration of 6 ns. We demonstrated a maximum pulse energy of 1 J for each gain medium as well as a repetition rate of 10 Hz for Yb:YAG and 1 Hz for Yb:QX glass, thus showing the feasibility and scalability of directly water-cooled, diode-pumped, high-energy short-pulse lasers.

Millijoule ultrafast optical parametric amplification as replacement for high-gain regenerative amplifiers

“…With this, we could enhance the pre-pulse contrast by almost three orders of magnitude to a level of , while maintaining the overall complexity of the laser system and keeping the ASE contrast at . In a next step, the system will be commissioned at the Petawatt ENergy-Efficient Laser for Optical Plasma Experiments (PEnELOPE) laser facility [ 32 ] at Helmholtz-Zentrum Dresden-Rossendorf in Dresden.…”

Spatio‐Temporal Characterization of Pump‐Induced Wavefront Aberrations in Yb3 + ‐Doped Materials

“…Previous investigations of Yb:CaF 2 neglected the electronic aberrations, which led to large deviations of the measured and theoretically determined OPDs . With the complete understanding of these aberrations, present‐day laser systems employing Yb 3 + ‐doped active materials, e. g., at the Helmholtz‐Zentrum Dresden‐Rossendorf (PEnELOPE) and the Helmholtz‐Institute Jena (POLARIS), which are designed for 1 PW peak power, can be optimized towards higher energies and an improved beam quality.…”

Index-leveling for forced-flow turbulent face-cooling of laser amplifiers

“…Different cooling liquids have been proposed, such as heavy water [7], organic solvents and special oils; however de-ionized water remains the most common coolant, thanks to the ease of use, low price and large thermal capacity of water. Many studies have also been devoted to the hydrodynamics of water under thermal charges, or optical transmission in turbulent media [8,9], allowing the laser physicist to benefit from decades-long insights by physicists of fluid mechanics.…”