Frequency conversion in Hydrogen of a Copper vapor laser by stimulated Raman scattering in hollow waveguides

In this paper we present the demonstration of stimulated Raman scattering frequency conversion in the red of the emission wavelengths of a small scale copper vapor laser by using pressurized H2 gas as the Raman medium. The threshold of this nonlinear process was suitably lowered to match the relatively low peak power of the pump by using guided propagation in a capillary waveguide. A conversion efficiency of 25% at 648 nm was recorded. Gemeration of new lines by frequency mixing processes in the blue and in the near infrared have been also observed. The achieved results can be scaled up to more powerful copper vapor laser systems, gaining in terms of conversion efficiency and average power of the generated lines.