Experimental control of pattern formation by photonic lattices

We study the control of modulational instability and pattern formation in a nonlinear dissipative feedback system with a periodic modulation of the material refractive index. We use a one-dimensional photonic lattice in a single-mirror feedback configuration and identify three mechanisms for pattern control: bandgap suppression of instability modes, periodicity induced pattern modes, and orientational pattern control.The authors acknowledge the support of the Conseil Régional de Lorraine, the bilateral FrenchAustralian Science and Technology program, and the Australian Research Council through Discovery projects

Quantum nonlinear metasurfaces

We review the latest advances in the generation of quantum light with nonlinear nanoresonators in metasurfaces, which act both as sources of quantum states and nanoantennas shaping the emitted photons. We outline a general quantum theory of spontaneous photon-pair generation in arbitrary nonlinear photonic structures, including nanoresonators and metasurfaces, which provides an explicit analytical solution for the photon state expressed through the classical Green function. We formulate the correspondence between the quantum photon-pair generation and classical sum-frequency process in nonlinear media, and discuss its application in various contexts, including waveguide circuits and nanostructures. We also discuss the first experimental results demonstrating photon-pair generation in a single nonlinear nanoantenna.Comment: 36 pages, 13 figures. arXiv admin note: text overlap with arXiv:1903.0695

Tunable fishnet metamaterials infiltrated by liquid crystals

We analyze numerically the optical response and effective macroscopic parameters of fishnet metamaterials infiltrated with a nematic liquid crystal. We show that even a small amount of liquid crystal can provide tuning of the structures due to reorientation of the liquid crystal director. This enables switchable optical metamaterials, where the refractive index can be switched from positive to negative by an external field. This tuning is primarily determined by the shift of the cut-off wavelength of the holes, with only a small influence due to the change in plasmon dispersio

Focusing and correlation properties of white-light optical vortices

We generate double-charge white-light optical vortices by sending a circularly polarized partially incoherent light through an uniaxial crystal. We show that the generated polichromatic vortices are structurally stable, and their correlation properties can be altered by the beam focusing, resulting in changes of the vortex core visibility.Comment: 6 pages, 4 figure

Nonlinear Bloch-wave interaction and Bragg scattering in optically-induced lattices

We study, both theoretically and experimentally, the Bragg scattering of light in optically-induced photonic lattices and reveal the key physical mechanisms which govern nonlinear self-action of narrow beams under the combined effects of Bragg scattering and wave diffraction, allowing for selecting bands with different effective dispersion.Comment: 4 pages, 6 figure