Mixts. of methane, H, and Ar (CH4:H2:Ar) were studied as UV Raman shifters for ozone differential absorption lidar application. They have higher photochem. stability than pure CH4 and the capability to produce, with high enough efficiency, either 1st CH4 Stokes or, simultaneously, CH4 and H2 1st Stokes with equal energies. These mixts. can be used as an inexpensive replacement for D2 or a more stable substitute for pure CH4 in single-pass high-power Raman shifters.