Abstract

A homogeneously broadened laser that is operated far above threshold can become unstable. This instability was first studied by Hillman et al.¹ with a high-Q ring dye laser. The optical spectrum of the laser, which originally was a single frequency, bifurcated into two symmetrically detuned optical frequencies at the instability threshold. The original laser frequency vanished discontinuously when the two new frequencies appeared. Recent theoretical studies of the Maxwell-Bloch equations² have demonstrated that such multifrequency solutions exist; however, the disappearance of the central frequency requires hard excitation.

© 1986 Optical Society of America