## F. Alpeggiani

25 records found

1

## Authored

The concept of topology has proven immensely powerful in physics, describing new phases of matter with unique properties. There has been a recent surge in attempts to implement topological protection in the photonic domain, owing to the application potential of robust transpor ...

We directly observe the states of topological photonic crystals at telecom wavelengths. Using the states’ intrinsic radiation, we measure dispersion, loss, pseudospin, and spin-spin scattering. We image spin-selective unidirectional propagation around sharp corners and junctio ...

When the positions of two generic singularities of equally signed topological index coincide, a higher-order singularity with twice the index is created. In general, singularities tend to repel each other when sharing the same topological index, preventing the creation of such ...

The emergence of two-dimensional transition metal dichalcogenide materials has sparked intense activity in valleytronics, as their valley information can be encoded and detected with the spin angular momentum of light. We demonstrate the valley-dependent directional coupling o ...

The two-dimensional excitons of transition metal dichalcogenide (TMDC) monolayers make these materials extremely promising for optical and optoelectronic applications. When the excitons interact with the electromagnetic field, they will give rise to exciton-polaritons, i.e., m ...

The chiral interaction between transverse optical spin and circularly polarized emitters provides a novel way to manipulate spin information at the nanoscale. Here, we demonstrate the valley(spin)-dependent directional emission of transition metal chalcogenides (TMDs) into pla ...

Spin and orbital angular momenta (AM) of light are well studied for free-space electromagnetic fields, even nonparaxial. One of the important applications of these concepts is the information transfer using AM modes, often via optical fibers and other guiding systems. However, ...

We demonstrate that the scattering matrix of nanophotonic systems is completely determined by their quasinormal modes and present a first-principle expansion technique which is directly applicable to an arbitrary number of modes and input-output channels.

@enWe develop a theoretical formalism which explains asymmetric transmission (AT) in chiral resonators from their eigenmodes. We derive a fundamental limit for AT and propose the design of a chiral photonic crystal offering 84% AT.

@enWe observe that the asymmetric transmission (AT) through photonic systems with a resonant chiral response is strongly related to the far-field properties of eigenmodes of the system. This understanding can be used to predict the AT for any resonant system from its complex eige ...

The scattering matrix is a fundamental tool to quantitatively describe the properties of resonant systems. In particular, it enables the understanding of many photonic devices of current interest, such as photonic metasurfaces and nanostructured optical scatterers. In this con ...