高斯涡旋光束的傍轴度

Degree of paraxiality for Gaussian vortex beams

按单色光束傍轴度的定义,对高斯涡旋光束的傍轴度进行了研究。使用角谱表示法推导出高斯涡旋光束傍轴度的解析公式,用此研究了傍轴度和高斯涡旋光束参数之间的关系。结果表明,随背景高斯光束束腰宽度和光涡旋离轴参数的增加及随光涡旋拓扑电荷的减少,高斯涡旋光束的傍轴度增加。对所得结果用傍轴度与远场发散角间的关系做了物理解释。

The degree of paraxiality for Gaussian vortex beams is studied based on the definition of the degree of paraxiality for monochromatic light beams.By using the angular spectrum representation,the analytical expression for the degree of paraxiality for Gaussian vortex beams is derived,and used to study the dependence of the degree of paraxiality on the Gaussian vortex beam parameters.It is shown that the degree of paraxiality for Gaussian vortex beams increases with increasing the waist width of background Gaussian beams or increasing the off-axis distance of optical vortices,and with decreasing the topological charge of optical vortices.The results are interpreted physically by using the relation between the degree of paraxiality and the far-field divergence angle.