Experimental investigation on excitability in a laser with a saturable absorber

In this work, we investigate experimentally the excitable properties of a solid-state laser with an intracavity saturable absorber. The main test of excitability is the characterization of the system response to short-pulse external stimuli. We present an original method to excite the system by injecting light pulses into the saturable absorber. This technique avoids imposing frequency tuning between the input laser and the passive laser, which is a necessary condition for field injection. We show that under certain conditions the laser behaves as an excitable system. The observed excitable regime is consistent with theoretical predictions for class-$B$ lasers with saturable absorber.