Mathieu-Gauss光束的焦开关

Focal Switch Effect of Mathieu-Gaussian Beams

研究Mathieu-Gauss(MG)光束通过光阑透镜分离系统的焦开关现象.由Collins公式,推导出了MG光束轴上光强分布公式,在此基础上作了大量的数值分析.研究发现,在光束参数和截断参数的适当取值下,MG光束存在焦开关现象.产生焦开关现象的条件是:光阑和透镜相对间距为1,光束参数必须大于其相应的临界值,而截断参数则须在它的两个临界值之间.

The focal switch effect of Mathieu - Gauss （MG） beams passing through a system with the aperture and lens separated is studied. The formula predominating the distribution of axial intensity of MG beams is derived. A large number of numerical calculation results are presented. It is shown that the focal switch of MG beams can take place as the beams parameter and truncation parameter are proper. For MG beams the conditions of focal switch are that the relative separation of the aperture and lens is 1, the beam parameter is must bigger than its corresponding critical value and the truncation parameter is must between its two corresponding critical values.