Influence of the 6^1S_0-6^3P_1 Resonance on Continuous Lyman-alpha   Generation in Mercury
  Continuous coherent radiation in the vacuum-ultraviolet at 122 nm (Lyman-alpha) can be generated using sum-frequency mixing of three fundamental laser beams in mercury vapour. One of the fundamental beams is at 254 nm wavelength, which is close to the 6^1S_0-6^3P_1 resonance in mercury. Experiments have been performed to investigate the effect of this one-photon resonance on phasematching, absorption and the nonlinear yield. The efficiency of continuous Lyman-alpha generation has been improved by a factor of 4.5. 
Daniel Kolbe and Martin Scheid and Jochen Walz
physics.optics physics.atom-ph