中国物理B ›› 2011, Vol. 20 ›› Issue (10): 104201-104201.doi: 10.1088/1674-1056/20/10/104201
何德3, 吕百达1, 高曾辉2
He De(何德)a)b),Gao Zeng-Hui(高曾辉) a)† , and Lü Bai-Da(吕百达)c)
摘要: This paper derives explicit expressions for the propagation of Gaussian beams carrying two vortices of equal charges m=±1 diffracted at a half-plane screen, which enables the study of the dynamic evolution of vortices in the diffraction field. It shows that there may be no vortices, a pair or several pairs of vortices of opposite charges m=+1, -1 in the diffraction field. Pair creation, annihilation and motion of vortices may appear upon propagation. The off-axis distance additionally affects the evolutionary behaviour. In the process the total topological charge is equal to zero, which is unequal to that of the vortex beam at the source plane. A comparison with the free-space propagation of two vortices of equal charges and a further extension are made.
中图分类号: (Wave optics)