Abstract

Tunable coherent radiation between 90 and 110 nm is generated by frequency tripling the output of a pulsed frequency-doubled dye laser in a free jet of rare gas atoms.¹ The XUV beam is crossed by an atomic Xe beam to observe single-photon transitions from the ground state of Xe to the autoionizing Rydberg series in the vicinity of the second ionization limit. A Stark field is applied in the interaction region. At moderate field strengths (>100 V/cm) wave functions with different / mix and transitions to the 5p⁵(²P_1/2) np series are observed in addition to the ns and nd series. The line intensities and shifts have been investigated for 0 < E < 2 kV/cm. As the third harmonic XUV beam is collinear with the high power fundamental UV laser radiation, the spectroscopy of many other species is obscured by UV multiphoton absorption processes. We have studied schemes for separating XUV and UV and will discuss the application of a dichroic beam splitter.²

© 1986 Optical Society of America