Quantum mechanics

Engineering

Communications system

Light beam

Telecommunications

Optical communication

Computer science

Physics

Orbital angular momentum of light

Quantum entanglement

Multiplexing

Total angular momentum quantum number

Free-space optical communication

Optics

Quantum information science

Angular momentum

Electronic engineering

Quantum

Orbital angular momentum multiplexing

Applied Physics Reviews

Structured light, especially beams carrying orbital angular momentum (OAM), has gained much interest due to its unique amplitude and phase structures. In terms of communication systems, multiple orthogonal OAM beams can be potentially utilized for increasing link capacity in different scenarios. This review describes challenges, advances, and perspectives on different aspects of the OAM-based optical communications, including (a) OAM generation/detection and (de)multiplexing, (b) classical free-space optical communication links, (c) fiber-based communication links, (d) quantum communication links, (e) OAM-based communications in different frequency ranges, (f) OAM-based communications using integrated devices, and (g) novel structured beams for communications.

Orbital angular momentum of light for communications