Raman parametric generation of anti-Stokes radiation under conditions of amplification of an external Stokes signal

Parametric generation of anti-Stokes radiation in a Raman amplifier was calculated theoretically and realized experimentally. An external Stokes signal propagated at an angle to a pump beam under phase-matching conditions. The second harmonic of an Nd laser (λ = 0.53 μm) was transformed in hydrogen at p ≈ 20 atm under saturated amplification conditions into the first anti-Stokes component (λ = 0.43 μm) and the efficiency of the process was ~ 11%.