G. Mourou

Ytterbium:glass CPA regenerative amplifier pumped by a free-running Ti:sapphire laser

Chirped pulse amplification (CPA) has enabled efficient energy extraction from solid-state lasers.1

High-energy flashlamp-pumped Ti:sapphire laser for Yb:glass chirped-pulse amplification

Summary form only given. A new flashlamp-pumped Ti:sapphire laser has been demonstrated for further high-energy Yb:glass chirped pulse amplification (CPA) experiments. The pulse energies of 6.5 J at 800 nm were obtained by from a flashlamp pumped Ti:sapphire laser in a system optimized for short-pulse discharge.

Isotope enrichment in highly-charged ionic species of ultrafast laser ablation plumes

Summary form only given. As reported recently for boron and gallium, we have measured factors greater than 2 for isotopic enrichment in the multiple-charge state ions from ultrafast laser ablation plasmas. The earlier work has now been extended to the elements Zn, Ti, and Cu. These results confirm the enrichment of the lighter isotope on the target-normal axis of the expanding ablation plume. Angular scans of these plumes demonstrate the persistence of the enrichment effect to wide angle, being present as far out as 45 degrees from the normal direction. Systematic variations in the dominant ion species and their energy distributions, as a function of charge state, are observed in these angular scans.

Application of ultrafast pulsed-laser deposition system for plasma-enhanced thin-film growth of III-nitrides

Summary form only given. Ultrafast laser plasmas have unique features compared to conventional (nanosecond) plasmas. Their time evolution is separated from the laser pulse allowing for pre-tuning of the plasma through variation of the pulse parameters. High ionic charge states exist in the expanding plasma which allow for multiple reaction channels in the background gas dynamics. Fast electrons provide a high-energy ion component beyond hydrodynamics which admits additional energy into both the film for ion-assisted growth and the background gas for reactive-gas growth. For higher-intensity laser pulses, the fast electrons can ionize the background gas, providing a plasma-enhanced thin-film growth. For intensities closer to the ablation threshold, a high-voltage grid can be used to accelerate the free electrons from the ablation plasma and ionize the background gas. The combination of a tunable ultrafast laser and a versatile deposition system allows broad-based control of the ablation plasma and the thin-film growth process. Such an ultrafast pulsed-laser deposition (PLD) system has been built for the plasma-enhanced thin-film growth of III-nitrides.