Characterisation of a saturated single frequency Ne-like Ge XUV laser on the J = 0→1 transition at 19.6 nm

We report on measurements of a saturated single frequency Ne-like Ge XUV laser on the J = 0->1 transition at 19.6 nm from a refraction compensating double target driven by 150 J of energy from 75 ps Nd-laser pulses. The 19.6 nm line completely dominated the laser output. The output energy was measured to be 0.9 mJ, corresponding to a conversion efficiency of 6×10⁻¹.