[2] A. Forbes, M. de Oliveira, M. R. Dennis. Structured light. Nat. Photonics, 15, 253-262(2021).
[3] A. E. Willner. OAM light for communications. Opt. Photonics News, 32, 34-41(2021).
[10] Y. Awaji, N. Wada, Y. Toda. Demonstration of spatial mode division multiplexing using Laguerre-Gaussian mode beam in telecom-wavelength, 551-552(2010).
[16] H. Hao et al. 100 Tbit/s free-space data link using orbital angular momentum mode division multiplexing combined with wavelength division multiplexing, 1-3(2013).
[17] J. Wang et al. In N-dimentional multiplexing link with 1.036-Pbit/s transmission capacity and 112.6-bit/s/Hz spectral efficiency using OFDM-8QAM signals over 368 WDM pol-muxed 26 OAM modes, 1-3(2014).