Abstract

An important aspect of any study of laser instabilities is the question of the conditions under which spontaneous pulsations will or will not occur. Stability criteria for ring-laser oscillators have been given previously, and we have now obtained the stability criteria for the more complex but also more important standing-wave lasers. We have completed a study of the stability criteria for homogeneously broadened standing-wave lasers, and extensions of this work to the general mixed-broadened laser configurations are in progress. A specific new result is that the lowest possible value of the threshold parameter of a standing-wave homogeneously broadened laser for which perturbation instability can occur is about r = 34 when the laser is tuned to line center. This is to be contrasted with the much lower value r = 9 for ring lasers. The high value for standing-wave lasers means that this type of instability would be extremely difficult to observe. As the relative amount of inhomogeneous broadening is increased, the instability threshold parameter for standing-wave lasers drops toward r = 1. The effect of detuning on the stability criteria has also been investigated.

© 1992 Optical Society of America