Structured light for free-space applications

This Collection supports and amplifies research related to SDG 9 - Industry, Innovation and Infrastructure.

The ability to control the phase, polarization, and intensity of light is extensively exploited in free space applications, ranging from high-capacity optical communication and remote sensing to quantum technologies. Structured beams (e.g., optical vortices carrying orbital angular momentum) provide additional degrees of freedom for encoding and encrypting information, making them valuable for applications in classical data transmission and quantum information processing.

Beyond optical communication, structured light can improve signal resilience, enhance spatial resolution, or extend the operational range of remote sensing. Furthermore, structured beams such as Bessel and Airy beams exhibit self-healing properties, improving resilience to environmental impairments (e.g., atmospheric turbulence, diffraction, and scattering). As a result of the above, the development of structured-light sources paired with real-time computational techniques for beam correction and mode sorting is accelerating the transition of free-space applications from a laboratory setting to field-ready implementations.

This focus collection in Communications Physics invites contributions reporting significant advances in the generation, propagation, and practical implementation of structured light in free-space environments, together with its integration into optical systems. The topics of interest include, but are not limited to:

• Free-space optical communications: Mode-division multiplexing and orbital angular momentum encoding for high-capacity data transmission.
• Quantum technologies: Structured photons for quantum key distribution and free-space quantum information processing.
• Remote sensing and environmental monitoring: Structured beams for turbulence-resilient long-distance sensing.
• Integration in optical systems: Real-time beam shaping platforms for free-space systems.
• Polarization and Spatial Encoding: Polarization-multiplexed and vector beam encoding schemes to enhance security.
• Preparation and detection of structured light: New methodologies for structured light preparation and detection in free-space applications.