Resonant third-harmonic generation a low-loss medium

The linear and nonlinear susceptibilities for resonant third-harmonic generation in an Mg-Kr system using the
3s^{2}-3s3d
two-photon resonance at 431 nm are presented. The Mg-Kr system is shown to be a suitable low-loss medium because of its small one-photon and two-photon absorption cross section. A detailed quantitative analysis up to a power conversion efficiency of
1.2 \cdot 10^{-4}
was carried out. The phase-matching curves and the intensity dependence are in excellent agreement with a nonstationary modification of the theory of resonant third-harmonic generation in high density, phase-matched systems recently presented by Puell et al. [4].