Spontaneous coherent pulsations in standing-wave laser oscillators: stability criteria for homogeneous broadening

Abstract

The stability criteria for single-mode standing-wave laser oscillators in the homogeneously broadened limit are reported, and two types of criteria are distinguished. The first type (type 1) corresponds to the minimum value of the threshold parameter for which an infinitesimal perturbation away from steady state grows into an oscillatory solution. A second type (type 2) corresponds to the minimum value of threshold parameter for which large-amplitude oscillations do not decay to the steady-state solution. Undamped pulsations in singlemode homogeneously broadened standing-wave laser oscillators are found to occur at a much higher excitation level than in ring-laser oscillators with homogeneous broadening. The effects of detuning on the stability criteria are also investigated.

Effects of focusing-beam field variations on the stability of laser oscillators

“…4 It has also been shown that the longitudinal field variations associated with a standing-wave model result in an increased threshold for laser instability. 9 For the present stability criteria studies, we have developed a semiclassical model for a single-longitudinal-mode, homogeneously broadened, unidirectional ring-laser oscillator with a focusing-beam laser field. In this model, as in many practical laser oscillators, the beam diameter is a function of longitudinal position between the laser mirrors.…”