A research team led by Professor Fu Shiyao and Professor Gao Chunqing from the School of Optics and Photonics at the Beijing Institute of Technology (BIT) has recently published an invited review in Photonics Insights at the invitation of the journal's editor-in-chief.

Titled "Orbital angular momentum tailoring toward high-dimensional photonics", the review was co-authored with Associate Professor Zhou Zhiyuan of the University of Science and Technology of China, Nanyang Assistant Professor Yijie Shen of Nanyang Technological University in Singapore, and Academician Andrew Forbes of the University of the Witwatersrand in South Africa.

BIT is the review's first-affiliated institution and one of its corresponding-author affiliations.

Orbital angular momentum (OAM) is one of the key degrees of freedom of a laser, and its eigenvalue can take any integer. This high-dimensional property has drawn growing attention in both classical and quantum optics, and tailoring laser OAM on demand underpins all of its applications. In recent years, OAM tailoring has expanded from single-mode control to the coordinated control of multiple modes, giving rise to high-dimensional photonics as a new research direction.

The review focuses on recent advances in laser OAM tailoring and their application scenarios. It begins with the fundamentals of OAM and its importance to high-dimensional photonics, then systematically surveys approaches to building OAM-based high-dimensional light fields, including OAM combs, classically nonseparable states, ultrahigh-degree-of-freedom beams, optical quasiparticles and spatiotemporal fields. It also examines emerging phenomena enabled by high-dimensional OAM tailoring in nonlinear and quantum optics, before discussing application scenarios, the key challenges they face and future directions for its development and application in optoelectronic systems.

The authors look ahead to applications of high-dimensional OAM fields in large-scale, high-capacity laser communication, multifunctional lidar and high-dimensional quantum information.

The work was supported by the Original Exploration Program of the National Natural Science Foundation of China and a key project under the Young Scientists Fund of the Beijing Natural Science Foundation.