Fig. 20. Metrology and astronomy using OVs.

a VBs can be used to detect the spin motion of an object²⁸⁵. b Twisted light can be used for label-free single-molecule detection²⁸⁷. c VBs can be used with plasmonic nanoslit structures for multi-channel OAM generation and detection²⁹¹. d Vortex generation around a rotating black hole³⁰². e–g Imaging of an OV coronagraph²⁹⁷. a From ref. ²⁸⁵. Reprinted with permission from AAAS. b Reprinted by permission from Springer Nature: Nature Materials²⁸⁷, Copyright (2019). c Reprinted with permission from ref. 291. Copyright (2019) by John Wiley and Sons. d Reprinted by permission from Springer Nature: Nature Physics³⁰², Copyright (2019). e–g Reprinted with permission from ref. ²⁹⁷, OSA Publishing