Commemorating 30 Years of Optical Vortices

Thirty years ago, Pierre Coullet et al. proposed that a special optical field exists in laser cavities bearing some similarity with the superfluid vortex. This observation was the first indicator that optical vortices could exist. Since then, optical vortices have been widely studied and have facilitated advances that range from optical tweezers, to quantum entanglement, to nonlinear optics. To commemorate “30 years of optical vortices,” researchers at Tsinghua University and other institutions in China have reviewed the history of optical vortices over the past three decades, beginning with how the concept of optical vortices emerged.

The researchers surveyed the steady refinement of the techniques used to create optical vortices and explore the application of these phenomena. They emphasized that the tunability of optical vortices includes not only the spectral and temporal tunability but also the orbital angular momentum, chirality, topological-charge, and singularity-distribution tunability.

During the first 10 years, which the researchers call the fundamental theories stage, the discovery of new physical concepts and phenomena, such as topological charge, phase singularity, vortex lattice, orbital angular momentum (OAM), and vortex beams provided the solid theoretical foundation necessary for subsequent scientific applications.

The researchers describe the next 10 years as the application development stage, when optical vortices were explored as light sources with superior performance for applications in quantum technology, particle manipulation, superresolution imaging, biomedical and chemical detection, optical communication, and other areas.

The past 10 years — considered the technology breakthrough stage — have seen optical vortices applied at the nanoscale. OAM-multiplexing has extended the capacity of optical communication to the terabit and even the petabit level, and improvements in the tunability of optical vortices have enabled novel nonlinear and quantum phenomena.

Commemorating the 30th anniversary of the prediction of optical vortices, researchers Xing Fu at Tsinghua University, Xiaocong Yuan at Shenzhen University, and co-authors reviewed the development of these intriguing phenomena over the past 30 years. Courtesy of Yijie Shen, Xuejiao Wang, Zhenwei Xie, Changjun Min, Qiang Liu, Mali Gong, and Xiaocong Yuan.

The researchers described optical vortices as an example of theory guiding new applications and application demands inspiring new theories. Optical vortices are still an important technology and have high potential for both theories and applications, the researchers said.

The research was published in Light Science & Applications (www.doi.org/10.1038/s41377-019-0194-2).