Swapping of orbital angular momentum states of light in a quantum well waveguide Seyyed Hossein Asadpour, Edris Faizabadi, Viaceslav Kudriašov, Emmanuel Paspalakis and Hamid. R. Hamedi Eur. Phys. J. Plus, 136 4 (2021) 457 Published online: 27 April 2021 DOI: 10.1140/epjp/s13360-021-01461-5