Four Wave Sum Difference Non-Linear Effects With X-Ray Lasers In A Gas Jet Plasma

Progress in a four-wave sum difference frequency generation scheme to convert quasi-coherent soft X-ray radiation to shorter wavelengths, using a plasma medium is discussed. Experimental results and calculations involving the Ne-like Ni XRL (lambda(XRL) = 0.023 mum) mixed in phase-matched mode with a Nd:glass laser at the second harmonic (lambda(OPT) = 0.52 mum) in a Na-like Argon plasma are presented. A 25 mm single slab target of Ni pumped with similar to 200 J of energy from 5 optical beams has routinely produced similar to 5 mJ of XRL energy at 23.1 nm. The XRL was split and recombined with the Nd:glass laser in the Na-like Ar plasma. Considerations for phase matching the XRL and optical beams in the ionized gas jet are also discussed.