Compressed-hydrogen Raman laser with parametric feedback

A loop generator operating on the basis of copropagating rotational stimulated Raman scattering in hydrogen is proposed. The idea has been implemented. This generator is shown to have a threshold gain and a high conversion efficiency. With pumping by a neodymium laser with an energy of 6 J in the pulse and a pulse length of 70 ns, the efficiency in terms of the energy of the conversion into the first Stokes component is about 50% at a divergence of 0.25 mrad. The pump signal (λ_p=1.06 μm) and the signal of generated light (λ_st=1.13 μm) can be separated in this layout.