Speckle pattern

Optics

Physics

Angular spectrum method

Optical vortex

Orbital angular momentum multiplexing

Physical chemistry

Angular momentum

Beam (structure)

Orbital angular momentum of light

Amplitude

Chemistry

Metrology

Polarization (electrochemistry)

Diffraction

Total angular momentum quantum number

Light field

Paraxial approximation

Classical mechanics

Frontiers in Physics

The paper briefly presents some essential concepts and features of light fields with strong spatial inhomogeneity of amplitude, phase, polarization, and other parameters. It contains a characterization of optical vortices, speckle fields, polarization singularities. A special attention is paid to the field dynamical characteristics (energy, momentum, angular momentum, and their derivatives), which are considered not only as mechanical attributes of the field but also as its meaningful and application-oriented descriptive parameters. Peculiar features of the light dynamical characteristics in inhomogeneous and dispersive media are discussed. The dynamical properties of paraxial beams and evanescent waves (including surface plasmon–polaritons) are analyzed in more detail; in particular, a general treatment of the extraordinary spin and momentum, orthogonal to the main propagation direction, is outlined. Applications of structured light fields for optical manipulation, metrology, probing, and data processing are described.

Structured Light: Ideas and Concepts