H. Zhang, W. Zhang, L. Xi, X. Tang, and X. Zhang, "A new design of a circular photonic crystal fiber supporting 42 OAM modes," in Australian Conference on Optical Fibre Technology, ACOFT 2016, September 5, 2016 - September 8, 2016, Sydney, Australia, 2016, p. American Elements; Australian Optical Society; cudos; Modular Photonics; OSA.