Interaction of two edge dislocations in free-space propagation

De He, Zeng-Hui Gao, Hong-Wei Yan, Bai-Da Lü
2011 Chinese Physics B  
This paper studies in detail the interaction of two edge dislocations nested in a Gaussian beam propagating in free space. It shows that in free-space propagation the edge dislocations are unstable and vanish, and two noncanonical vortices with opposite topological charge take place when off-axis distances c 1 and c 2 of two edge dislocations are nonzero, and the condition k 2 w 8 0 + 32c 1 c 2 (w 2 0 − 2c 1 c 2 )z 2 > 0 is fulfilled (k-wave number, w 0 -waist width). A noncanonical vortex
more » ... rs when one off-axis distance is zero. However, one edge dislocation is stable when two edge dislocations are perpendicular and one off-axis distance is zero. Two perpendicular edge dislocations both with zero off-axis distance are also stable. The analytical results are illustrated by numerical examples.
doi:10.1088/1674-1056/20/1/014201 fatcat:5ffxpdrzmrbajiej7updtjowb4