Local Estimation of Orbital and Spin Angular Momentum Mode Numbers
Résumé
At radio frequencies, previous works by Mohammadi et al. derived from quantum mechanics, state that the spin (SAM), orbital (OAM) and their sum (the total angular momentum TAM), can be estimated locally without ambiguity. In this article, we highlight an inconsistency in this method when adding a SAM with an OAM. The latter can not be estimated for a non-zero SAM. From optical currents, we propose a more general method. It is based on the Poynting expansion into spin and orbital components to estimate the OAM regardless of the SAM value.