Thermo-optical pulsing in a microresonator filtered fiber-laser: a route towards all-optical control and synchronization

Abstract

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 thermooptical 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 selforganization 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.

Self-emergence of robust solitons in a microcavity

“…2a , blue region). Although this condition is usually incompatible with stable soliton states, in our case, two slow and energy-dependent non-linearities arising from the EDFA in the main fibre cavity, as well as the thermal response of the microresonator 52 , non-locally modify the state of the system as the energy increases. This process intrinsically creates a dominant attractor: the system moves from the laser start-up region into a distinct stability region for the desired soliton state, which is naturally formed and intrinsically maintained without any external control.…”

Self-Emergence of Robust Micro Cavity-Solitons

“…2a). While this condition is usually incompatible with stable soliton states, in our case, two slow and energy-dependent nonlinearities arising from the EDFA in the main fibre cavity as well as the thermal response of the microresonator 52 nonlocally modify the state of the system as the energy increases. This process intrinsically creates a dominant attractor: the system moves from the laser start-up region into a distinct stability region for the desired soliton state, which is then naturally formed and, most importantly, intrinsically maintained without any external control.…”

Optically tunable photoluminescence and upconversion lasing on a chip

“…The existence of sets of forces acting with opposite magnitudes and on different characteristic timescales can lead to instabilities in the optomechanical resonator. Such instabilities have been reported in a variety of systems, where the thermo-optic effect in the cavity is opposed by free carrier dynamics [56], thermo-mechanical forces [7,57,58], gain dynamics in an external cavity [59] or the Kerr effect [60]. In each work a strong force with a short timescale pushes the resonator out of equilibrium, after which it slowly returns to its initial position through a force acting in the opposite direction.…”

“…for biosensing [7] and for all-optical control and synchronization [59]. An interesting question for future work is whether the additional optomechanical dynamics and loss channels due to the intracavity gain medium introduced here interacts with the self-pulsing instability, creating new forms of self-pulsing dynamics (e.g.…”