Abstract

In this paper, we report what we believe to be the first observation of nonlinear generation of light within an absorption window created by an interference between two nearby autoionizing levels. The absorption cross section within the window is reduced by more than 10², making the medium transparent to the generated radiation at 104.8 nm. However, with a suitable choice of intermediate levels the four-wave-mixing susceptibility, χ⁽³⁾, does not experience a similar cancellation within the window, allowing a dramatic increase in the conversion efficiency.

© 1990 Optical Society of America