Ultra-Degree-of-Freedom Structured Light for Ultracapacity Information Carriers

Structured light recently highlighted the higher-dimensional control with many tailored degrees of freedom (DoFs) such as amplitude, wavelength, polarization, and orbital angular momentum (OAM), spurring extension fundamental science advanced applications, especially novel information carrier to meet requirement everlastingly increasing communication bandwidth security. In addition basic DoFs in light, there are also several complex hidden spin–orbital coupled vector beams, ray-wave geometric modes, spatiotemporal vortex rings, etc., extending structured manipulation. this Review, we summarize a systematic technical roadmap on how extend multiple step-by-step beyond conventional OAM creating new forms ultra-DoF present tutorial exploit carriers, recent assistance artificial intelligence or deep learning method, enhancing capacity, security, dimension for next-generation technologies.