Through systematically manipulating the couplings in the photonic lattice, the topological nature emerges associated with edge state dynamics. Here, we demonstrate a robust photonic zero mode sustained by a spatial non-Hermitian phase transition in a parity-time (PT) symmetric lattice despite the same topological order across the entire system and a flexible topological photonic lattice with multiple topologically nontrivial dispersion bands. Heterodyne measurements clearly reveal the ultrafast transport dynamics and energy of the edge states at a femtosecond scale, validating the designed topological features.
Structured light and structured matter are two fascinating branches of modern optics that recently started having a significant impact on each other. However, integrating structured light, which commonly is created using bulk optics, on miniaturized silicon chips represents a significant challenge. In this talk, we discuss fundamental optical phenomena at the interface of structured light and engineered optical structures, including theoretical and experimental studies of light-matter interactions of vector and singular optical beams in optical metamaterials and microcavities. The synergy of complex beams, such as the beams carrying an orbital angular momentum (OAM), with nanostructured “engineered” media is likely to bring new dimensions to the science and applications of structured light ranging from fundamentally new regimes of spin-orbit interaction to novel ways of information encoding for the future optical communication systems.
We show that unique optical properties of engineered micro- and nanosctructures open unlimited prospects to “engineer” light itself. We discuss several approaches to ultra-compact structured light wavefront shaping using metal-dielectric and all-dielectric resonant metasurfaces. Moreover, by exploiting the emerging non-Hermitian photonics design at an exceptional point, we demonstrate a microring laser generating a single-mode OAM vortex lasing with the ability to precisely define the topological charge of the OAM mode. We show that the polarization associated with OAM lasing can be further manipulated on demand, creating a radially polarized vortex emission. Our OAM microlaser could find applications in the next generation of integrated optoelectronic devices for optical communications in both quantum and classical regimes.