We present simple methods to produce optical vortices on the axis of beam propagation with nonspiral phase plates. We show that a phase plate that provides linear phase retardation on one half of a laser beam produces optical vortices, which is demonstrated experimentally by use of a thickness-varying glass platelet. We also demonstrate and explain that mixed dislocations of a bent edge dislocation transform into a pair of vortices with opposing topological charges.
© 1997 Optical Society of America
Guang-Hoon Kim, Jin-Ho Jeon, Kwang-Hoon Ko, Hee-Jong Moon, Jai-Hyung Lee, and Joon-Sung Chang, "Optical vortices produced with a nonspiral phase plate," Appl. Opt. 36, 8614-8621 (1997)