Konstantin Bliokh
In the first part of this talk, I will discuss the main momentum and angular-momentum properties of structured monochromatic waves, including electromagnetic, acoustic, and other types. The canonical wave momentum density is associated with the local phase gradient of the wavefield. In turn, the angular momentum density consists of the orbital part (fully determined by the canonical momentum density) and the spin part, produced by the local rotation (elliptical polarization) of the vector wavefield. These properties are universal across different types of waves, and essentially determine their dynamical properties. In the second part, I will describe the main topological structures which appear in monochromatic waves. These include type-I vortices (phase singularities) at the nodal points of scalar wavefields, type-II vortices around 'holes' in 2D systems, polarization singularities (C-points of purely circular polarization) accompanied by the polarization Möbius strips around them, and skyrmions formed by the instantaneous vector-field directions. I will also present recent experimental results on the generation of these structures in optical, sound, and water waves.