In this paper we present some results of the experimental study on the conversion of highly coherent XeCl-laser radiation by use of the SRS process in compressed gaseous hydrogen. About 70 rotational-vibrational components were obtained with the use of a circularly polarized pump beam. It is shown in the paper that the axial vibrational components possess high spatial and temporal coherence under conditions of phase locking in four-wave mixing processes. In the case of only Raman conversion the quantum efficiency into the first vibrational Stokes component was 95%.