Abstract
Orbital angular momentum (OAM) has been an enthralling topic of research from fundamental physics to technological applications since its discovery in 1992. Many techniques have been developed to generate OAM such as using spiral phase plates (SPPs), computer-generated holograms (CGH) and cylindrical mode converters, etc. However, these methods are based on bulky optics that cause a major hindrance for their exploitation in the emerging area of micron-nanophotonics. Recently, generation of such helical beams by micron-sized structures has gained momentous interest to make their appliance possible at small scale. This paper recapitulates these endeavors of minuscule optical vortex generation. Five different types of compact optical vortex generators, i.e., downscaling of conventional OAM generators, plasmonic vortex lens (PVLs), metasurfaces, integrated OAM emitters and subwavelength apertures are brought under discussion.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
