Abstract

A resonant sum-difference frequency mixing scheme in Kr has been investigated and the conversion efficiency was found to be enhanced by electromagnetically induced transparency [1]. The four-wave mixing scheme (figure 1) is driven by two fields, one in the UV at 212.55nm is in two-photon resonance and the second at 759nm is in single photon resonance with transitions in the atom. It is the second field the coupling laser, that dresses the atom so as to create the laser induced transparency (via destructive interference). The conversion efficiency is enhanced by the effect of induced transparency, induced phase matching and the constructive interference in the non-linear susceptibility [2]. Accompanying the four-wave mixing is photoionisation of the atoms by the UV field (see figure 1).

© 1998 IEEE