Current status of the LUCIA laser system

DiPOLE - An Efficient and Scalable High Pulse Energy and High Average Power Cryogenic Gas Cooled Multi-Slab Amplifier Concept

“…Even in its current state, the measured maximum average power of 64 W and corresponding η o-o of 16% compare very favourably to other ongoing high-energy DPSSL projects. The respective values for average power and efficiency are 550 W and 7.6% for Mercury [9], 20 W and 5.7% for LUCIA [10], 213 W and 11.7% for HALNA [11], and 1.2 W and 6% for Polaris [12]. Once the new extraction scheme is in place, we expect to demonstrate η o-o greater than 25% at much higher coolant temperature, which will further improve the overall efficiency of the system.…”

Direct thermal diffusion bonding of Nd:YAG/YAG composite transparent ceramics by vacuum sintering

“…Neodymium nitrate (Nd(NO 3 99.99%) and ammonium aluminum sulfate (NH 4 Al(SO 4 ) 2 ·12H 2 O, 99.99%) were mixed together in stoichiometric proportions to form the chemical stoichiometry composition, with Nd 3+ doping concentrations of 0 at.% and 2.0 at.%, respectively, in distilled water. The precipitant solution was prepared by dissolving ammonium hydrogen carbonate (NH 4 HCO 3 , analytical grade) in mixed solvent of alcohol and distilled water.…”

“…It is well-known that the YAG crystals applied to high-power laser programs such as HiPER and LUCIA must guarantee large-size and high quality gain medium of its own kind with a good thermal conductivity [2,3]. Unfortunately, the limit of the conventional Czochralski (CZ) technique [4] to fabricate the desired Nd-doped YAG single crystals is that it introduces the defects which would affect the laser performance, such as cores or light-scattering particles, inhomogeneous distribution of laseractive dopant and contamination of boule [5].…”

High-energy, ceramic-disk Yb:LuAG laser amplifier

“…We achieve an optical-to-optical efficiency of more than 20%, mainly due to regenerative pumping, which is comparably high for a pulsed laser system operating at room temperature. Previous works reporting on diode-pumped Yb:YAG amplifiers with similar pulse energies [12,13] or even more than 1 J [14,15] either demonstrated a maximum optical-to-optical efficiency around 10% or relied on cryogenic cooling, and/or based on bulk material [16][17][18]. While cryogenically cooled lasers allow for even higher efficiencies the gain spectrum is narrowed dramatically for both Yb:YAG and Yb:LuAG.…”