Abstract

The ability to introduce additional tunable resonances in the nonlinear optical susceptibility of a medium by the injection of an additional radiation field is an attractive possibility from the standpoint of efficient tunable frequency-mixing processes in the VUV. The possibility of such processes was suggested to us by the observations in atomic mercury, where an enhancement of several orders of magnitude in the third-harmonic generation efficiency was reported when the input frequency was four-photon resonant with the 6S → 6D transition.¹

© 1984 Optical Society of America