Physical Review A
Constructive interference and efficient vacuum-ultraviolet generation in resonant six-wave mixing
Nandini Mukherjee
Abstract
We consider four-photon resonant six-wave mixing and show that the efficiency of harmonic generation is limited due to destructive interference between different optical harmonics. Following the idea of ``induced transparency'' of Harris et al. [Phys. Rev. Lett. 64, 1107 (1990)], it is shown that in the presence of an auxiliary electromagnetic coupling between the four-photon excited level and a third level, the interference between various excitation channels can be made constructive. Depending upon the strength of the auxiliary wave, absorption and dispersion-free propagation of the generated wave lead to high conversion efficiency.