Characteristics of amplified spontaneous emissions in high-gain gas-laser amplifiers

Formulas were developed for gain and spectral line-narrowing, including saturation intensity for incident broadband amplified spontaneous emissions. By introducing a new parameter, the ratio of incident linewidth to Doppler linewidth and the degree of saturation, the dependence of the gain and spectral line-narrowing upon laser parameters such as Lorentz linewidth, Doppler linewidth and gain parameter of partially homogeneously broadened laser amplifiers was modeled. The formulas are applied to the characteristic xenon 3.51 micron gas-laser amplifier.