High‐efficiency four‐wave sum mixing in magnesium at 140 nm

摘要: In magnesium, bound‐continuum matrix elements contribute constructively to the magnitude of third‐order nonlinear susceptibility χ(3ω)(3) for sum‐frequency mixing in region first continuum. Thus, continuously tunable harmonic radiation 140–160 nm (9000 cm−1) can be readily obtained with two dye lasers modest power. The onset saturation vacuum ultraviolent intensity at 1436 was not observed until incident powers ⩾30 kW, where measured power conversion efficiency 0.2%.