Measuring orbital angular momentum of a vortex beam with atom-based structured light
Nawaz Sarif Mallick
Abstract
This study presents an innovative scheme for detecting the orbital angular momentum (OAM) of vortex beams within an atomic ensemble. Leveraging a homogeneously broadened four-level atomic system driven by two orthogonal polarization probe beams, we demonstrate the selective generation of structured beams without the need for magnetic fields between the two ground states. Through detailed theoretical analysis and numerical simulations, we elucidate the phase-dependent behavior of atomic coherences induced by an OAM-carrying Laguerre–Gaussian optical probe beam. These findings enable the creation of petal-like structures within the probe beam, with the number of petals directly correlated to the OAM value. Our investigation underscores the potential of this OAM detection scheme as a highly sensitive and precise sensor, applicable across diverse domains such as telecommunication, microscopy, and optical metrology.