The development trends and research fronts in orbital angular momentum technology: A bibliometric analysis

Orbital angular momentum (OAM) technology, refers to Laguerre-Gaussian (LG) beams, twisted beams, vector/vortex beams, acoustic vortex beams and fractional vortex beams. It is an emerging and promising technology to improve the communication capacity, spectral efficiency, and anti-jamming capability due to its helical phase fronts and infinite orthogonal states. Although the OAM research began in the 1990s, the developing trends, current status, issues and characteristics through a systematic observation have not yet been performed. This paper presents a knowledge-based evolution of OAM research published in the Web of Science (WoS) from 2011 to 2021 using bibliometric analysis in Citepspace. The results demonstrate that the bandwidth, efficiency, gain, divergence, phase quantization, bulky and complex feeding structures, misalignment, distortion, interferences atmospheric turbulence and diffraction were the key issues found in the OAM technology. The main research hotspots and categories, influential authors, leading journals, best institutions of OAM show a strong bias in favor of their functions and technology developments. The research on OAM was mainly performed by the counties that have developed the 5G and now moving towards 6G communications like China, USA and South Korea. This study would serve as an inclusive guide on the future research trends and status especially for the OAM researchers.