title: Cascadable excitability in microrings.
abstract: To emulate a spiking neuron, a photonic component needs to be excitable. In this paper, we theoretically simulate and experimentally demonstrate cascadable excitability near a self-pulsation regime in high-Q-factor silicon-on-insulator microrings. For the theoretical study we use Coupled Mode Theory. While neglecting the fast energy and phase dynamics of the cavity light, we can still preserve the most important microring dynamics, by only keeping the temperature difference with the surroundings and the amount of free carriers as dynamical variables of the system. Therefore we can analyse the microring dynamics in a 2D phase portrait. For some wavelengths, when changing the input power, the microring undergoes a subcritical Andronov-Hopf bifurcation at the self-pulsation onset. As a consequence the system shows class II excitability. Experimental single ring excitability and self-pulsation behaviour follows the theoretic predictions. Moreover, simulations and experiments show that this excitation mechanism is cascadable.
authors.affiliation: Photonics Research Group (INTEC), Ghent University - imec, Sint-Pietersnieuwstraat 41, B-9000 Ghent, Belgium. thomas.vanvaerenbergh@intec.ugent.be
authors.forename: Thomas
authors.initials: T
authors.lastname: Van Vaerenbergh
authors.forename: Martin
authors.initials: M
authors.lastname: Fiers
authors.forename: Pauline
authors.initials: P
authors.lastname: Mechet
authors.forename: Thijs
authors.initials: T
authors.lastname: Spuesens
authors.forename: Rajesh
authors.initials: R
authors.lastname: Kumar
authors.forename: Geert
authors.initials: G
authors.lastname: Morthier
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schrauwen
authors.forename: Joni
authors.initials: J
authors.lastname: Dambre
authors.forename: Peter
authors.initials: P
authors.lastname: Bienstman
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D032701:Biomimetics / Q000295:instrumentation*; D003198:Computer Simulation; D005246:Feedback; D006801:Humans; D008959:Models, Neurological; D009474:Neurons / Q000502:physiology*; D055096:Optical Devices