Gain-dependent dispersion in a XeF laser

The effects of gain-dependent optical dispersion in rare-gas halide lasers are investigated within the framework of a semiclassical laser theory that gives analytically the frequency dependence of the gain and anomalous dispersion. Results are presented for the case of a XeF laser. From the point of view of output-beam quality in a XeF amplifier, an important result is that the phase shift is zero when the amplifier is operated at a wavelength that is detuned 1.2 A to the red of the gain maximum; at this wavelength, the gain is reduced by only about 20%.