Spatial-diversity detection of optical vortices for OAM signal modulation
Abstract
We propose a method for identifying orbital angular momentum (OAM) states within a vortex superposition using a Shack–Hartmann (SH) sensor as a spatial-diversity detector. We define a local OAM at every pixel of the SH image, from which we construct an OAM spectrum. The topological charges are determined from the OAM spectrum using a low-complexity algorithm, resulting in estimates that are robust to beam wandering. Data from a 200 m experimental transmission are successfully tested using the proposed technique.
- Publication:
-
Optics Letters
- Pub Date:
- October 2020
- DOI:
- 10.1364/OL.397771
- Bibcode:
- 2020OptL...45.5534A