Efficient higher-Stokes-order Raman conversion in molecular gases

Abstract

Efficient conversion of ultraviolet-laser output to visible radiation has been demonstrated with multiple Stokes Raman amplification in hydrogen gas using an oscillator–amplifier combination. Initial experiments with the third harmonic of a Q-switched Nd:YAG laser at 355 nm yielded nearly complete pump depletion in a 2-m amplifier, whereas photon-conversion efficiencies of 49 and 51% have been observed for the first and second Stokes orders, respectively.