Vacuum ultraviolet , nonlinear tunability

P.O. Sorokin, J.J. Wayne, J.A. Armstrong, R.T. Hodgson, Resonantly enhanced, nonlinear generation of tunable, coherent, vacuum, ultraviolet (VUV) light in atomic vapours, Ann. N. Y. Acad. Sci. 267 (1976) 30. 

ABSTRACT. Tunable coherent radiation in the ultraviolet and vacuum ultraviolet has been generated by stimulated Raman scattering, by anti-Stokes Raman lasers, and by frequency mixing processes in nonlinear media. The theory and experimental progress in the development of these laser-driven sources is reviewed, and examples of available systems and their characteristics are discussed. Various applications in spectroscopy of radiation tunable in the wavelength region 200-90 nm are presented. 

Practically all laser analytical techniques are based on systems with tunable wavelength. By using different types of lasers and the methods of nonlinear optics, one can obtain intense tunable laser radiation over the spectral range of 0.2-40 pm and in some regions of the vacuum ultraviolet and far infrared. Almost any strong... 

Besides the various types of tunable lasers discussed in the foregoing sections, sources of tunable coherent radiation have been developed that are based on the nonlinear interaction of intense radiation with atoms or molecules in crystals or in liquid and gaseous phases. Second-harmonic generation, sum- or difference-frequency generation, parametric processes, or stimulated Raman scattering are examples of such nonlinear optical mixing techniques. These techniques cover the whole spectral range from the vacuum ultraviolet (VUV)... 

---