  We report on 'slow' pulsing dynamics in a silica resonator-based laser
system: by nesting a high-Q rod-resonator inside an amplifying fiber cavity, we
demonstrate that trains of microsecond pulses can be generated with repetition
rates in the hundreds of kilohertz. We show that such pulses are produced with
a period equivalent to several hundreds of laser cavity roundtrips via the
interaction between the gain dynamics in the fiber cavity and the
thermo-optical effects in the high-Q resonator. Experiments reveal that the
pulsing properties can be controlled by adjusting the amplifying fiber cavity
parameters. Our results, confirmed by numerical simulations, provide useful
insights on the dynamical onset of complex self-organization phenomena in
resonator-based laser systems where thermo-optical effects play an active role.
In addition, we show how the thermal state of the resonator can be probed and
even modified by an external, counter-propagating optical field, thus hinting
towards novel approaches for all-optical control and sensing applications.
