[4] P. J. Winzer. Modulation and multiplexing in optical communication systems, 23, 4-10(2009).
[10] K. Dholakia, T. Čižmár. Shaping the future of manipulation. Nat. Photonics, 5, 335-342(2011).
[13] M. Padgett, R. Bowman. Tweezers with a twist. Nat. Photonics, 5, 343-348(2011).
[15] M. R. Dennis et al. Isolated optical vortex knots. Nat. Phys., 6, 118-121(2010).
[19] G. Molina-Terriza, J. P. Torres, L. Torner. Twisted photons. Nat. Phys., 3, 305-310(2007).
[26] D. L. Begley. Free-space laser communications: a historical perspective, 3, 391-392(2002).
[29] D. Divsalar, F. Pollara. Multiple turbo codes for deep-space communications(1995).
[36] Y. Zhao et al. Experimental demonstration of 260-meter security free-space optical data transmission using 16-QAM carrying orbital angular momentum (OAM) beams multiplexing, Th1H.3(2016).
[38] V. W. S. Chan. Free-space optical communications. J. Lightwave Technol., 24, 4750-4762(2006).
[39] H. A. Willebrand, B. S. Ghuman. Fiber optics without fiber. IEEE Spectr., 40, 41-45(2001).
[40] E. Leitgeb. Current optical technologies for wireless access, 7-17(2009).
[44] L. Li et al. Performance enhancement of an orbital-angular-momentum-based free-space optical communication link through beam divergence controlling, M2F.6(2015).