F. Ple

Optimization toward a high-average-brightness soft-x-ray laser pumped at grazing incidence

We report the near-field imaging characterization of a 10 Hz Ni-like 18.9 nm molybdenum soft-x-ray laser pumped in a grazing incidence pumping (GRIP) geometry with a table-top laser driver. We investigate the effect of varying the GRIP angle on the spatial behavior of the soft-x-ray laser source. After multiparameter optimization, we were able to find conditions to generate routinely a high-repetition-rate soft-x-ray laser with an energy level of up to 3 microJ/pulse and to 6x10(17) photons/s/mm2/mrad2/(0.1% bandwidth) average brightness and 1x10(28) photons/s/mm2/mrad2/(0.1% bandwidth) peak brightness.

Carrier-envelope phase stabilization of a terawatt level chirped pulse amplifier for generation of intense isolated attosecond pulses

We demonstrate the first carrier-envelope phase (CEP)-stabilized chirped pulse amplification system with pulse peak-powers in the terawatt regime. The system, which eventually is intended to be used in the generation of isolated attosecond pulses, consists of two consecutive multipass amplification stages. The first amplification stage is a commercial CEP-stable kHz system including a single 13-pass amplifier reaching a pulse energy of 2.3 mJ. Pulses are picked after the first stage at a repetition rate of 50 Hz and are further amplified in a 5-pass power-amplifier to pulse energies that reach up to 80 mJ before compression. After compression the pulse energy is 35mJ at a pulse duration of 32 fs, signifying a peak power of 1.1 terawatt. Peak-powers exceeding 1.5 TW should easily be achievable by improving the efficiency of the grating compressor. The CEP-stability of the terawatt system is demonstrated by single shot measurements of the residual CEP jitter at the full repetition rate and show an excellent root-mean-square value of 315 mrad.

Quantitative study of 10 Hz operation of a soft x-ray laser-energy stability and target considerations

A soft x-ray laser from Ni-like Mo, pumped in grazing incidence (GRIP), is analyzed with regard to high repetition rate operation. Reliable lasing is obtained, but with significant energy fluctuations attributed mainly to beam pointing jitter from the pump laser. Two modes of operation are compared: continuously moving target and stationary target. With a moving target the soft X-ray output is constant on average, whereas the repeated use of the same target position leads to a pulse energy which increases for several tens of shots. This effect might be caused by improved guiding of the pump laser in the formed groove and the removal, through laser ablation, of the oxide layer on the target surface.

ILE 25PW single laser beamline: The French step for the European Extreme Light Infrastructure (ELI)

We present the design of a single ultra intense laser beamline delivering 25PW pulses at one shot per minute as a first step of an ultra intense high field science European project (extreme light infrastructure).

Suppression of parasitic lasing in large-aperture Ti:sapphire amplifiers. Amplifying strategies for high rep-rate petawatt class Ti:sapphire systems

We have studied experimentally and theoretically the parasitic lasing phenomenon in large-aperture Ti:sapphire crystals to optimize the amplification scheme of petawatt class Ti:sapphire laser. Simulations, first experimental results and strategy of amplification will be presented.

Wavefront correction and aberrations pre-compensation in the middle of Petawatt-class CPA laser systems

We describe preliminary experiences to validate correction of wavefront aberrations in middle of laser chain. This technique allows correction of aberrations from first part, and the pre-compensation of aberrations built in second part of laser.

Analysis and solutions for parasitic lasing in Petawatt and multi-Petawatt Ti: sapphire laser systems

We have studied experimentally and theoretically the parasitic lasing phenomenon in large-aperture Ti:sapphire crystals to optimize amplification schemes of multi-petawatt class Ti:sapphire laser. Simulations and experimental results of high power amplification will be presented.

Towards high energy 10 fs laser pulse via regenerative pulse shaping

We demonstrated the use of regenerative pulse shaping approach to obtain ultrashort pulses with at the output of titanium: sapphire laser system. This scheme can be scaled to higher output energy and sub 10fs pulses.

Beams homogenization to pump Petawatt class Ti:Sapphire crystals

We have tested two optical solutions to homogenize the spatial profile of nanosecond pump beams to be used for a Petawatt Ti:Sapphire. Simulations and experiments will be presented for microlens arrays and random phase plate.

A high repetion rate petawatt class Ti:sapphire system

We have demonstrated 33 J amplification in Ti: sapphire at the record repetition rate of 0.1 Hz. For this, we have successfully removed transverse lasing in the large crystal amplifier and homogenized the laser pump profiles.