Diffraction characteristics of variable diaphragm on the fundamental Gaussian beam
As a common optical device,variable diaphragm has been widely used in beam shaping and spatial filtering experiments.The working principle of the variable diaphragm determines that its aperture is not a round hole,but a multilateral arc,which leads to some interesting spot patterns in the near field when the light is diffracted by the variable diaphragm,such as gear-shaped pattern.In this paper,the detailed experiments about the near-field diffraction phenomenon of the variable dia-phragm were performed,and theoretical simulations were conducted by using the Matlab on the dif-fraction of a multilateral arc diaphragm.The theoretical simulation was coincident with the experi-mental results.