Optics and Photonics Society of Iran

In this article, the propagation of vortex beams in the presence of an opaque obstacle is investigated. The intensity distribution of the diffracted beam due to the edge of the opaque obstacle is simulated using the angular spectrum and Huygens convolution propagation methods. It has been shown that the vortex beams have a relative self-healing property so that the diffracted intensity distribution of these beams are healed asymmetrically through propagation. This phenomenon occurs for a larger topological charge at shorter propagation distances. It has also been shown that the direction of self-healing is related to the topological charge sign, and therefore the use of the diffraction pattern from the edge of the opaque obstacle is a simple and fast way to determine the topological charge sign.