Parametric Raman anti-Stokes laser

A parametric Raman anti-Stokes laser utilizing compressed hydrogen (p = 50 atm) was developed and investigated. It was used to generate anti-Stokes radiation at 433 nm (15 ns pulse duration) by parametric interaction between the pump radiation (530 nm, 50 ns) and the Stokes beam (680 nm). The parametric Raman coupling between the optical fields occurred because the resonator was aligned for the Stokes radiation at the phase-matching angle with respect to the pump radiation. A power conversion efficiency of 6% was achieved experimentally. Numerical calculations for this laser indicated that a 40% conversion efficiency was feasible in the cw regime for pump radiation with a divergence no higher than 10 ^– 4 rad.