Evolution of elegant Laguerre–Gaussian beam disturbed by an opaque obstacle

Abstract

The evolution of the intensity distribution and Poynting vector of elegant Laguerre–Gaussian (LG) beam disturbed by an opaque obstacle are analytically studied and numerically calculated. Results show that when the propagation distance is shorter, the intensity distribution rotates with the propagation distance, and the speed of rotation is lower for high-order elegant LG beam. Meanwhile, the distribution gets worse and worse. However, further increasing the propagation distance we can see that the rotation of the intensity stops and that its intensity distribution becomes a regular distribution like a ring shape.