Department of Electrical and Computer Engineering;
National University of Singapore;
Singapore 117583;
Singapore;
Institute of Materials Research and Engineering;
Agency for Science;
Technology and Research;
Singapore 138634;
Singapore;
Department of Optics and Optical Engineering;
University of Science and Technology of China;
Hefei 230026;
China;
SUPA;
School of Physics and Astronomy;
University of Glasgow;
Glasgow G128QQ;
UK;
Information Technology University of the Punjab;
Lahore 54000;
Pakistan;
NUS Graduate School for Integrative Science and Engineering;
National University of Singapore;
Singapore 117456;
Singapore;
The Edward S Rogers Department of Electrical and Computer Engineering;
University of Toronto;
Toronto M5S 3G4;
Canada;
SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology;
Shenzhen University;
Shenzhen 518060;
China;
NUS Suzhou Research Institute(NUSRI);
Suzhou 215123;
China;
metasurface; nanophotonics; orbital angular momentum; superposition state;