Production of an extremely cold plasma by optical-field-induced ionization

Residual energy in optical-field-ionized plasmas with the longitudinal motion of electrons included

The space-charge effect on the residual energy of electrons in optical-field-ionized plasmas is studied in detail by an extended simplified model and the cloud-in-cell simulation, with the longitudinal motion of electrons included. It is found that in moderate conditions the space-charge field can influence the residual energy of electrons effectively by matching the space-charge field with laser pulse. The effect of stimulated Raman scattering on electron temperature is also investigated in detail. Finally, a comparison is made between the results and experimental data.

Saturated amplification of a collisionally pumped optical-field-ionization soft X-ray laser at 41.8 nm

We report the first saturated amplification of an optical-field-ionization soft x-ray laser. The amplifying medium is generated by focusing a circularly polarized 330-mJ, 35-fs, 10-Hz Ti:sapphire laser system in a few-mm cell filled with xenon. A gain of 67 cm(-1) on the 4d(9)5p-4d(9)5d transition at 41.8 nm in Pd-like xenon and a gain-length product of 15 have been inferred at saturation. This source delivers about 5 x 10(9) photons per pulse. The influence of the pumping energy and the laser polarization on the lasing output are also presented.