Theory of single-mode laser instabilities

Fluctuation in population pulsations resulting from the presence of corresponding pulsations in the field are shown to be a common element in single-wavelength and multiwavelength laser instabilities. Laser amplitude and frequency equations are derived from the wave equation; the medium is represented by the nonlinear polarization. Both the standing wave (SW) case and the running wave case are treated, and the difference between the present analysis and that of optical-bistability instability is shown. Single-wavelength and multiwavelength laser instabilities are investigated for the special case of a strong central mode turned to line-center. A generalized treatment, including detuning effects, is then presented. Some numerical results for homogeneously and inhomogeneously broadened lasers are presented, and some numerical correlations and predictions for the He-Xe SW laser are given.