HIGH-POWER TUNABLE IR RAMAN LASERS

Physical principles, new ways and means of creation, schemes, characteristics and features of efficient high-power tunable pulse Raman lasers, operating in the near and middle ir are reviewed. The paper includes: tunable dye and Nd lasers as pump sources; promising active media and their optimal excitation methods; optical systems for producing spatially homogeneous pumping; the physics of Raman oscillators and their practical schemes, efficient high pulse energy liquid N2 and compressed H2 Raman oscillators, covering several bands in the range between 1.4 and 9.2 μm; the physics and construction of efficient tunable Raman amplifiers-convertors, amplifying in the saturation regime of spontaneously scattered or beforehand produced and collimated external Stokes signals, obtained in the spectral range between 0.83 μm and 18 μm. Raman laser using a, so-called, broadband pump where the linewidth of pumping light is broader than the spontaneous scattering linewidth, are also discussed. Features of both amplification and oscillation regimes of such broadband pumped Raman lasers are reported, and conditions for the efficient frequency conversion are determined. © 1978 Springer-Verlag.