中文摘要：

实验研究了带有相反拓扑指数的Laguerre-Gaussian（LG）模间的相互作用，发现含有相反拓扑指数的两个LG模在传播过程中其光场发生变化，观察到随着传播距离的增加，两个LG模的中心位相奇点会逐渐连成为一个弧形暗线形状．实验上验证了带有相反拓扑指数的光学涡流中的螺旋位错在传播过程中会演变为边位错这一理论结果．

英文摘要：

The interaction of two Laguerre-Gaussian （LG） modes carrying opposite topological charges in a linear medium is investigated experimentally. The changes of diffractive pattern are observed when these two LG modes propagate, and a dark arc happens by the central dark particles of the two LG modes joining together in case the interaction of two LG modes carrying opposite topological charges propagate in a linear medium. This experimental phenomenon proves that the screw phase dislocations evolve into a new type of dislocation-edge phase dislocation with the optical field propagating.