  We examine the dynamics of laser droplet generation in dependence on the
detachment pulse power. In the absence of the detachment pulse, undulating
pendant droplets are formed at the end of a properly fed metal wire due to the
impact of the primary laser pulse that induces melting. Eventually, these
droplets detach, i.e. overcome the surface tension, because of their increasing
mass. We show that this spontaneous dripping is deterministically chaotic by
means of a positive largest Lyapunov exponent and a negative divergence. In the
presence of the detachment pulse, however, the generation of droplets is
fastened depending on the pulse power. At high powers, the spontaneity of
dripping is completely overshadowed by the impact of the detachment pulse.
Still, amplitude chaos can be detected, which similarly as the spontaneous
dripping, is characterized by a positive largest Lyapunov exponent and a
negative divergence, thus indicating that the observed dynamics is
deterministically chaotic with an attractor as solution in the phase space. In
the intermediate regime, i.e. for low and medium detachment pulse powers, the
two chaotic states compete for supremacy, yielding an intermittent
period-doubling to amplitude chaos transition, which we characterize by means
of recurrence plots and their properties. Altogether, the transition from
spontaneous to triggered laser droplet generation is characterized by a
chaos-to-chaos transition with an intermediate dynamically nonstationary phase
in-between. Since metal droplets can be used in various industrial
applications, we hope that the accurate determination of the dynamical
properties underlying their formation will facilitate their use and guide
future attempts at mathematical modeling.
