Detall

Conferenciant: Prof. Ramon Herrero

Resum: Periodic potentials introduce the possibility to modify the dispersion of waves. In particular, light can be managed by passive or active structured materials, linear and nonlinear metamaterials and metasurfaces.

Hermitian periodic potentials, based on refractive index modulations, show typical applications like spatial filters, self-focusing, flat lensing, shaping of light beams or flat focusing mirrors. The less studied non-Hermitian potentials, with refractive index and gain/loss modulations, induce not only diffraction modifications but also light diffusion.

Further, a particular class of non-Hermitian potentials induce asymmetries and directionalities in the wave coupling breaking the dispersion symmetry. It allows several unprecedented features such as the control of scattering, the generation of directionality fields for shaping the flow of light or the invisibility of arbitrary shaped objects that break the laws of closed conservative systems.

Aside, non-Hermitian photonics provides new tools to modify the stability of stationary states in nonlinear systems. Applications such as the control of turbulence or the stabilization of semiconductor lasers and amplifiers will be discussed.