Progress on laboratory-size ultra-intense soft x-ray lasers
Date | Mo, 29.02.2016 | |
Time | 14.15 | |
Speaker | Stéphane Sebban Laboratoire d’optique appliquée, École Polytechnique and ELI beamlines, Palaiseau, France | |
Location | Empa, Dübendorf, Theodor-Erismann-Auditorium, VE102 | |
Program | Emerging applications of coherent soft x-ray sources, notably in biology, require high energy and ultrashort pulse duration in the femtosecond-scale to probe the ultra-fast dynamics of matter in the nanometer scale. Alongside current efforts to provide high brilliance x-ray coherent sources with X-ray free electron lasers, significant potential lays in the realization of compact and relatively cheap ultra-intense x-ray coherent sources. Plasma-based soft x-ray lasers turn out to be good candidates since they can emit a large number of photon (up to 10^15 per pulse) within a narrow linewidth and exhibit high-quality optical properties once seeded with high-harmonic sources. However, the duration of these sources has been limited so far to the picosecond range consequently restricting the field of possible applications. In this presentation, we report on an original method able to generate intense femtosecond soft x-ray lasers pulse based on ultrafast ionization gain gating in a high-density plasma. By focusing a few 10^18 W.cm^2 laser driving pulse into a high-density optically pre-formed krypton plasma waveguide, we observed a strong amplified spontaneous emission at 32.8 nm. For electronic density as high as about 2x10^20cm-3, the measurement of the gain life time provides evidence of generating about 100 fs soft soft x-ray lasers pulses containing a few μJ. Overcoming previous bottlenecks in terms of pulse duration and peak brightness, this scheme may be paving the way for prospective laboratory-scale ultraintense soft x-ray lasers beams. |