厄米双曲余弦高斯光束通过光阑透镜的位相奇点

Phase singularities of Hermite-cosh-Gaussian beams passing through an aperture lens

对厄米双曲余弦高斯光束通过光阑透镜的位相奇点进行了研究。数值计算结果表明截断参数δ和离心参数b都会影响厄米双曲余弦高斯光束通过光阑透镜的位相奇点分布。随着截断参数的增大,通过光阑透镜的厄米双曲余弦高斯光束的位相奇点发生产生和湮灭,在整个过程中总的拓扑电荷守恒。当b≤0.97时,奇点A,B互相靠近而湮灭;0.97<b≤2.79时,奇点B,C互相靠近而湮灭,奇点A不参与湮灭过程且始终处于焦平面上。随着离心参数b的继续增大,将有不同的奇点参与类似的分裂和湮灭过程。通过数值结果阐明了通过光阑透镜的厄米双曲余弦高斯光束位相奇点的产生和湮灭过程。

The phase singularities of Hermite-cosh-Gaussian beams in passage through an aperture lens were studied. Numerical calculation results were given to illustrate the dependence of phase singularities of focused Hermite-cosh-Gaussian beams on the truncation parameter δ and decentered parameter b. It is shown that as the truncation parameter 6 gradually increases, the creation and annihilation process of phase singularities of focused Herrnite-cosh-Gaussian beams take place, and the total topological charge is conserved during the process. For the decentered parameter b ≤0.97, the singularities A and B approach each other and annihilate, whereas for the decentered parameter 0.97〈b≤2.79, the singularities B and C approach each other and annihilate, and the singularity A remains in the focal plane. With the increasing of decentered parameter b, the creation and annihilation process continues with the next pair of phase singularities. At last, the creation and annihilation process of phase singularities of focused Hermite-cosh- Gaussian beams is illustrated by numerical examples.