We have analyzed total spin angular momentum of surface waves localized at a metasurface described within an effective conductivity approach. We show that hybrid TE-TM polarized surface waves propagating along the anisotropic metasurface provide unprecedented control over the spin angular momentum of light. The obtained results can be used in a number of photonic applications.
We provide an overview of recent theoretical and experimental studies, which revisited the basic dynamical properties of light: momentum and angular momentum. Recently, we described qualitatively new types of the spin and momentum in structured optical fields. These are: (i) the transverse spin, which is orthogonal to the wave vector and is independent of the helicity, and (ii) the anomalous transverse momentum, which depends on the helicity of light. Both of these quantities were described and measured experimentally in various optical systems, and they are currently attracting rapidly growing attention. In particular, the transverse spin in evanescent waves has found promising applications for robust spin-controlled unidirectional coupling to surface and waveguide optical modes. In turn, the transverse momentum provides a weak spin-dependent optical force, which is orthogonal to both the propagation direction and the intensity gradient in a wave field.
It is well known that, for any monochromatic field, the spatial extent of the focus has a lower bound dependent
on the field's directional spread. The influence that the orbital angular momentum and, for vector fields, the
(spin) angular momentum due to polarization have on this lower bound are studied here for fields not constrained
by the paraxial approximation. A ray-optical interpretation of the effect of orbital and spin angular momentum
on the spatial spread is provided for the case of Bessel beams.
We give an exact self-consistent operator description of the spin and orbital angular momenta, position, and spin-orbit
interactions of nonparaxial light in free space. We apply the general theory to symmetric and asymmetric Bessel beams
exhibiting spin- and orbital-dependent intensity profiles. The exact wave solutions are clearly interpreted in terms of the
Berry phases, quantization of caustics, and Hall effects of light, which can be readily observed experimentally.
Conference Committee Involvement (1)
Third International Conference on Optical Angular Momentum