Detecting optical vortices in 2D


  • Dina Grace C. Banguilan ⋅ PH National Institute of Physics, University of the Philippines Diliman
  • Nathaniel P. Hermosa II ⋅ PH National Institute of Physics, University of the Philippines Diliman


Higher-order optical vortices are inherently unstable in the sense that they tend to separate in a series of vortices with a unity charge. In this study, we demonstrate a technique to detect an optical vortex using its far-field diffraction by a triangular aperture. By raster scanning a triangular aperture in two dimensions across a beam containing a single vortex, we record the resulting structured diffraction pattern. Then, we measure the intensity signal at the pattern's center. We do this by introducing a pinhole whose size S can be controlled. By plotting the intensity values transmitted through the pinhole for different scanning points, we find that the lowest intensity region in the map locates a vortex. We show through another experiment that our technique is able to resolve vortex pairs that are 86.4 μm apart. Our results can be significant in understanding multiple-vortex interactions in other optical beams, such as in x-ray and electron beams.



Article ID



Optics and Photonics



How to Cite

DGC Banguilan and NP Hermosa, Detecting optical vortices in 2D, Proceedings of the Samahang Pisika ng Pilipinas 41, SPP-2023-1B-04 (2023). URL: