Hysteresis of an Ar+ laser with a nonlinear intracavity absorber

Phenomenological representations and the results of an experimental study of the emission from an Ar⁺ laser with passive mode locking were used to analyze the nature of hysteresis of the output power near the threshold. It was found that hysteresis and passive mode locking were inseparable because both effects were due to the same processes of saturation of amplification and absorption.