Double raman scattering scheme for an XUV laser

A new method is proposed to achieve XUV generation in an He-K mixture medium excited by an electrical discharge by means of a double stimulated Raman scattering (SRS) process. First a dye laser of 404 nm radiation is down-converted to
\lambda_{s} = 1.209 \mu
m in a Stokes SRS and then the produced IR radiation is up-converted to
\lambda_{as} = 64
nm in an anti-Stokes SRS. The overall calculated efficiency of conversion of violet pulse energy into XUV pulse energy reaches
2 \cdot 10^{-4}
in a traveling-wave-type regime with tight focusing and 22 MW pumping power. The XUV pulse energy may reach 12.3 μJ and is limited by excited potassium quartet atoms density (
8 \cdot 10^{11}
cm
^-4
for this case). The pump power may be lowered by using an IR resonator. Then with 6 ns pulse duration, the same XUV output energy as in the traveling-wave regime may be achieved with
1.7 \cdot 10^{-4}
efficiency and a violet pump power of 14 MW.