Finite series expressions to evaluate the beam shape coefficients of a Laguerre-Gauss beam focused by a lens in an on-axis configuration

摘要

Pursuing a study concerning the evaluation of Beam Shape Coefficients (BSCs) of Laguerre-Gauss beams, after having dealt with the case of beams freely propagating, the present paper establishes finite series expressions to evaluate the BSCs of Laguerre-Gauss beams focused by a lens, which have the known advantage of speeding up computations with respect to the use of numerical quadrature techniques and which may deal with the limitations of localized approximations in the case of beams exhibiting topological charges and/or axicon angles. (C) 2019 Elsevier Ltd. All rights reserved.