Tuning of the emission frequency of a gas-discharge $XeCl$ laser

A diffraction grating was used in an investigation of narrowing of the emission line and tuning of the output frequency of an $XeCl$ laser. Two resonator configurations were used and in these configurations the grating was in the Littrow and grazing-incidence mountings. The spectral line width was less than 0.02 nm and tuning in the vicinity of the 308.0 and 308.2 nm lines was achieved.