Fast identification of orbital-angular-momentum states in vector beams

The measurement of optical vortices constitutes a critical aspect within the photonics domain, with the fast identification of orbital-angular-momentum (OAM) states in vector beams presenting considerable challenges, especially when compared with their counterparts in scalar beams. In this work, we introduce a swift and efficient identification scheme designed specifically for OAM states in vector beams. This innovative scheme enables the simultaneous detection of vortex modes and polarization characteristics through a single-shot measurement. Employing a vector mode decomposition method technique, our approach utilizes advanced polarization conversion and polarization preservation strategies. This methodology has been rigorously developed within a theoretical framework and has been demonstrated in a straightforward, easily implementable experimental setup. The proposed method holds substantial promise for advancing fundamental research in optical topology and quantum state engineering, while also facilitating the applications of OAMs in optical communication.