1. Beth, R. A., "Mechanical detection and measurement of the angular momentum of light," Physical Review, Vol. 50, No. 2, 115-125, 1936.
doi:10.1103/PhysRev.50.115
2. Jackson, J. D., Classical Electrodynamics, Nuclear Physics, John Wiley & Sons Ltd., New York, 1963.
3. Allen, L., M. W. Beijersbergen, R. J. Spreeuw, and J. P. Woerdman, "Orbital angular momentum of light and the transformation of Laguerre-Gaussian laser modes," Physical Review & Atomic Molecular & Optical Physics, Vol. 45, No. 11, 81-85, 1992.
4. Gibson, G., et al. "Free-space information transfer using light beams carrying orbital angular momentum," Optics Express, Vol. 12, No. 22, 5448-5456, 2004.
doi:10.1364/OPEX.12.005448
5. Ren, Y., et al. "Experimental characterization of a 400 Gbit/s orbital angular momentum multiplexed free-space optical link over 120 m," Optics Letters, Vol. 41, No. 3, 622-625, 2016.
doi:10.1364/OL.41.000622
6. Yao, A. M. and M. J. Padgett, "Orbital angular momentum: Origins, behavior and applications," Advances in Optics & Photonics, Vol. 3, No. 2, 161-204, 2011.
doi:10.1364/AOP.3.000161
7. Padgett, M. J. and L. Allen, "The angular momentum of light: Optical spanners and the rotational frequency shift," Optical & Quantum Electronics, Vol. 31, No. 1, 1-12, 1999.
doi:10.1023/A:1006911428303
8. Torner, L., J. Torres, and S. Carrasco, "Digital spiral imaging," Optics Express, Vol. 13, No. 3, 873-881, 2005.
doi:10.1364/OPEX.13.000873
9. Torres, J. P. and L. Torner, Twisted Photons: Applications of Light with Orbital Angular Momentum, Wiley-VCH, 2011.
doi:10.1002/9783527635368
10. Thide, B., et al. "Utilization of photon orbital angular momentum in the low-frequency radio domain," Physical Review Letters, Vol. 99, No. 8, 087701, 2007.
doi:10.1103/PhysRevLett.99.087701
11. Mohammadi, S. M., et al. "Orbital angular momentum in radio --- A system study," IEEE Transactions on Antennas & Propagation, Vol. 58, No. 2, 565-572, 2010.
doi:10.1109/TAP.2009.2037701
12. Tamburini, F., et al. "Encoding many channels in the same frequency through radio vorticity: First experimental test," New Journal of Physics, Vol. 14, No. 3, 811-815, 2011.
13. Lin, M., Y. Gao, P. Liu, and J. Liu, "Super-resolution orbital angular momentum based radar targets detection," Electronics Letters, Vol. 52, No. 13, 1168-1170, 2016.
doi:10.1049/el.2016.0237
14. Yuan, T., H. Wang, Y. Qin, and Y. Cheng, "Electromagnetic vortex imaging using uniform concentric circular arrays," IEEE Antennas & Wireless Propagation Letters, Vol. 15, 1024-1027, 2016.
doi:10.1109/LAWP.2015.2490169
15. Tamburini, F., et al. "Experimental demonstration of free-space information transfer using phase modulated orbital angular momentum radio," Physics, Vol. 13, No. 2, 20-25, 2013.
16. Zhang, Z., S. Zheng, X. Jin, H., Chi, and X. Zhang, "Generation of plane spiral OAM waves using traveling-wave circular slot antenna," IEEE Antennas & Wireless Propagation Letters, Vol. 16, 8-11, 2016.
17. Yu, S., L. Li, G. Shi, C. Zhu, X. Zhou, and Y. Shi, "Design, fabrication, and measurement of reflective metasurface for orbital angular momentum vortex wave in radio frequency domain," Applied Physics Letters, Vol. 108, No. 12, 5448, 2016.
doi:10.1063/1.4944789
18. Yu, S., G. Shi, C. Zhu, and Y. Shi, "Generating multiple orbital angular momentum vortex beams using a metasurface in radio frequency domain," Appl. Phys. Lett., Vol. 108, No. 24, 241901, 2016.
doi:10.1063/1.4953786
19. Jin, J., et al. "Generation and detection of orbital angular momentum via metasurface," Scientific Reports, Vol. 6, 24286, 2016.
doi:10.1038/srep24286
20. Chen, M. L. N., L. J. Jiang, and W. E. I. Sha, "Artificial perfect electric conductor-perfect magnetic conductor anisotropic metasurface for generating orbital angular momentum of microwave with nearly perfect conversion efficiency," Journal of Applied Physics, Vol. 119, No. 6, 064506, 2016.
doi:10.1063/1.4941696
21. Chen, M. L. N., L. J. Jiang, and W. E. I. Sha, "Ultrathin complementary metasurface for orbital angular momentum generation at microwave frequencies," IEEE Transactions on Antennas & Propagation, Vol. 65, No. 1, 396-400, 2017.
doi:10.1109/TAP.2016.2626722
22. Chen, M., L. J. Jiang, and W. E. I. Sha, "Detection of orbital angular momentum with metasurface at microwave band," IEEE Antennas & Wireless Propagation Letters, Vol. 17, No. 1, 110-113, 2018.
doi:10.1109/LAWP.2017.2777439
23. Xu, H. X., H. Liu, X. Ling, Y. Sun, and F. Yuan, "Broadband vortex beam generation using multimode pancharatnam{berry metasurface," IEEE Transactions on Antennas & Propagation, Vol. 65, No. 12, 7378-7382, 2017.
doi:10.1109/TAP.2017.2761548
24. Zhang, Y., L. Yang, H. Wang, X. Zhang, and X. Jin, "Transforming surface wave to propagating OAM vortex wave via flat dispersive metasurface in radio frequency," IEEE Antennas & Wireless Propagation Letters, Vol. 17, No. 1, 172-175, 2018.
doi:10.1109/LAWP.2017.2779269
25. Li, Y., B. Liang, Z. M. Gu, X. Y. Zou, and J. C. Cheng, "Reflected wave-front manipulation based on ultrathin planar acoustic metasurfaces," Scientific Reports, Vol. 3, 2546, 2013.
doi:10.1038/srep02546
26. Yu, N., et al. "Light propagation with phase discontinuities reflection and refraction," Science, Vol. 334, 333-337, 2011.
doi:10.1126/science.1210713
27. Khorasaninejad, M., W. T. Chen, R. C. Devlin, J. Oh, A. Y. Zhu, and F. Capasso, "Metalenses at visible wavelengths: Diffraction-limited focusing and subwavelength resolution imaging," Science, Vol. 352, 1190-1194, 2016.
doi:10.1126/science.aaf6644
28. Ma, X., et al. "A planar chiral meta-surface for optical vortex generation and focusing," Scientific Reports, Vol. 5, 10365, 2015.
doi:10.1038/srep10365
29. Holloway, C. L., E. F. Kuester, J. A. Gordon, J. O'Hara, J. Booth, and D. R. Smith, "An overview of the theory and applications of metasurfaces: The two-dimensional equivalents of metamaterials," IEEE Antennas & Propagation Magazine, Vol. 54, No. 2, 10-35, 2012.
doi:10.1109/MAP.2012.6230714
30. Cai, B., L. Zhou, Q. He, S. Xiao, T. J. Cui, and X. Li, "Flat metasurfaces to focus electromagnetic waves in re," Optics Letters, Vol. 37, No. 23, 4940-4942, 2012.
doi:10.1364/OL.37.004940
31. Fukumoto, H., H. Sasaki, D. Lee, and T. Nakagawa, "Beam divergence reduction using dielectric lens for orbital angular momentum wireless communications," International Symposium on Antennas and Propagation IEEE, 680-681, 2Okinawa, Japan, Oct. 016.