Generalization and propagation of spiraling Bessel beams with a helical axicon
Sun Qiong-Ge(孙琼阁), Zhou Ke-Ya (周可雅), Fang Guang-Yu (方光宇), Liu Zheng-Jun(刘正君), and Liu Shu-Tian (刘树田)
Chin. Phys. B . 2012, (1): 14208 -014208 .  DOI: 10.1088/1674-1056/21/1/014208