Recognizing OAM Modes of Electromagnetic Laguerre-Gaussian Schell-Model Vortex Beams in Atmospheric Turbulence from Polarization

A key element of orbital angular momentum (OAM) multiplexing technology that still requires innovation is the accurate identification of the OAM mode at the receiving end. Herein, based on the electromagnetic Laguerre-Gaussian Schell-model vortex (ELGSMV) beam (2020 J. Opt. 22 91), analytical expressions for four properties are obtained: average intensity, degree of polarization (DoP), orientation angle of polarization (OAoP), and ellipticity. The OAoP and ellipticity distributions of ELGSMV beams in relation to the topological charge l and order p are investigated. This is innovatively demonstrate that the OAoP and ellipticity distributions of the ELGSMV beam are the petal-like shape, with the number of petals being twice as large as the corresponding topological charge. And, the positive or negative value of the topological charge affects the direction in which the petal rotates. In addition, the ELGSMV beam has a higher resistance to atmospheric turbulence than the general partially coherent vortex beam from the perspective of the DoP properties. These novel results may not only propose an effective method for recognizing the OAM mode of a partially coherent vortex beam, but also provide a theoretical basis for the selection of high-quality beams in applications like quantum information and wireless optical communication. By studying the changes of intensity, OAoP and ellipticity of LGSMV beams with different orders and topological charges after being transmitted through atmospheric turbulence, the authors innovatively demonstrate that the OAoP and ellipticity distributions of the ELGSMV beam can be used to identify the magnitude and direction of the topological charge, while the intensity distribution of the ELGSMV beam propagating through atmospheric turbulence when the order p takes a non-zero value can only identify the magnitude of the topological charge. image