Enhanced generation of VUV radiation by four-wave mixing in mercury using pulsed laser vaporization

Sebastien Chenais (1) , Sebastien Forget (1) , Laurent Philippet (1) , Marie-Claude Castex (1)

1 LPL - Laboratoire de Physique des Lasers

The efficiency of a coherent VUV source at 125 nm, based on 2-photon resonant four-wave mixing in mercury vapor, has been enhanced by up to 2 orders of magnitude. This enhancement was obtained by locally heating a liquid Hg surface with a pulsed excimer laser, resulting in a high density vapor plume in which the nonlinear interaction occurred. Energies up to 5 μJ (1 kW peak power) have been achieved while keeping the overall Hg cell at room temperature, avoiding the use of a complex heat pipe. We have observed a strong saturation of the VUV yield when peak power densities of the fundamental beams exceed the GW/cm2 range, as well as a large intensity-dependant broadening (up to ~30 cm-1) of the two-photon resonance. The source has potential applications for high resolution interference lithography and photochemistry.

Mots clés: laser; VUV source; four-wave mixing

Domaines: Optique [physics.optics]

Sebastien Chenais, Sebastien Forget, Laurent Philippet, Marie-Claude Castex. Enhanced generation of VUV radiation by four-wave mixing in mercury using pulsed laser vaporization. Applied Physics B - Laser and Optics, 2007, 89, pp.223-229. ⟨hal-00148878⟩