We propose a chaos communication scheme based on a chaotic optical phase carrier generated with an optoelectronic oscillator with nonlinear time-delay feedback. The system includes a dedicated non-local nonlinearity, which is a customized three-wave imbalanced interferometer. This particular feature increases the complexity of the chaotic waveform and thus the security of the transmitted information, as these interferometers are characterized by four independent parameters which are part of the secret key for the chaos encryption scheme. We first analyze the route to chaos in the system, and evidence a sequence of period doubling bifurcations from the steady-state to fully developed chaos. Then, in the chaotic regime, we study the synchronization between the emitter and the receiver, and achieve chaotic carrier cancellation with a signal-to-noise ratio up to 20 dB. We finally demonstrate error-free chaos communications at a data rate of 3 Gbit/s.

The large field enhancement that can be achieved in high quality factor and small mode volume photonic crystal microcavities leads to strengthened nonlinear interactions. However, the frequency shift dynamics of the cavity resonance under a pulsed excitation, which is driven by nonlinear refractive index change, tends to limit the coupling efficiency between the pulse and the cavity. As a consequence, the cavity enhancement effect cannot last for the entire pulse duration, limiting the interaction between the pulse and the intra-cavity material. In order to preserve the benefit of light localization throughout the pulsed excitation, we report the first experimental demonstration of coherent excitation of a nonlinear microcavity, leading to an enhanced intra-cavity nonlinear interaction. We investigate the nonlinear behavior of a Silicon-based microcavity subject to tailored positively chirped pulses, enabling to increase the free carrier density generated by two-photon absorption by up to a factor of 2.5 compared with a Fourier-transform limited pulse excitation of equal energy. It is accompanied by an extended frequency blue-shift of the cavity resonance reaching 19 times the linear cavity bandwidth. This experimental result highlights the interest in using coherent excitation to control intra-cavity light-matter interactions and nonlinear dynamics of microcavity-based optical devices.

We present a study on the transient operation of a microcavity under a coherent excitation. Through appropriate shaping of the incident signal, the coupling efficiency and the enhancement of the non-linearities are shown to be increased.

Coherent excitation of a nonlinear semiconductor microcavity is theoretically reported. It intends to counterbalance the frequency drift of the cavity resonance driven by the nonlinear refractive effects, which causes a limitation in the energy coupling efficiency of an input pulse into the cavity resonance. We show that exciting such a nonlinear microcavity with tailored chirped pulses allows to maintain the benefit of light localization and to further enhance light-matter interactions, opening the way to the realization of highly efficient nonlinear devices.

Les microcavites a grand facteur de qualite et faible volume modal permettent, grâce a un fort effet de confinement de la lumiere, le renforcement des interactions lumiere-Matiere et la realisation de futurs dispositifs pour le traitement optique de l’information a faible energie de commande. Ce travail de these traite du fonctionnement de microcavites a cristal photonique en regime d’excitation coherente, base sur des impulsions dont la relation temps-Frequence est controlee afin de renforcer les interactions non lineaires intracavite.La modelisation de la dynamique non lineaire de ces cavites a l'aide de la theorie des modes couples, a permis de mettre en avant le role des non-Linearites refractives sur la reduction des effets de localisation au cours de l'excitation.Nous proposons alors de controler la dynamique du champ intracavite par un controle de la relation temps-Frequence des impulsions.Cette excitation dite coherente, repose sur la mise en œuvre d'un montage de mise en forme d'impulsions, constitue d'un etireur d'impulsions et d'un dispositif de filtrage spectral.La caracterisation non lineaire de nanoguides en silicium a permis, en complement du modele, la determination precise des parametres des impulsions.Nous avons ensuite realise la toute premiere demonstration experimentale de l'excitation coherente de microcavites, menant a la fois a un renforcement des interactions non lineaires et une reduction des distorsions subies par les impulsions transmises par la cavite.

We report our recent efforts for the design and fabrication of comb slot photonic crystal waveguides in silicon on insulator photonics. The main issues related to dispersion engineering, investigation of slow mode optical losses, and modal confinement metrics, have been investigated in various geometries. Nonlinear χ(3) optical properties have then been explored using a pump probe picosecond experiment and the obtained trends and results are discussed.

Nonlinear microcavities are known to exhibit an intensity-dependent refractive index. This effect causes a mismatch between the resonance of the cavity and the input pulse frequency, resulting in a limitation of the energy coupling efficiency. We show here that a phase shaping of the input pulse allows to maintain the benefit of light localization.