Frequency up-conversion to the VUV in Hg vapor

The efficient generation (up to 1 percent, 10 kW) of tunable, narrow-band radiation in the spectral ranges 1219-1221 Å, 1228- 1235 Å, and 1247-1255 Å, using two-photon resonant, four-wave sum mixing in Hg vapor, is reported, using both the planewave and the tight focusing situations. Oscillator strengths are derived from the planewave experiments for the
6s^{1}S_{0}-9P, 10p
, and
11p^{1}P_{1}
transitions with an accuracy of 3 percent.