Anti-Stokes Raman scattering to the vacuum ultraviolet spectral region in rare-gas discharge plasmas

An investigation was made of anti-Stokes Raman scattering of YAG:Nd³⁺ laser radiation to the vacuum ultraviolet spectral region from the 2p⁵3p neon levels excited in a hollow cathode discharge. Radiation was generated at wavelengths 62.3–63.0 nm in lines having spectral widths of 1 cm^–1 within which tuning was possible. The wavelengths of the lines were determined with an accuracy of better than 10^–3 nm. When the initial level was pumped from a metastable level using a second laser, the intensity of the anti-Stokes Raman scattering vacuum ultraviolet line almost doubled and at a wavelength of 62.434 nm, for example, the spectral brightness was 10¹⁵ photons/(s·cm²·sr·cm^–1). This is comparable with the spectral brightness of the best synchrotron radiation sources.