On localized approximations for Laguerre-Gauss beams focused by a lens

Autor(es)

Ambrosio, Leonardo Andre ^[1] ; Gouesbet, Gerard ^{[2, 3]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, Dept Elect & Comp Engn, 400 Trabalhador Sao Carlense Ave, BR-13566590 Sao Carlos, SP - Brazil

^[2] INSA Rouen, Campus Univ Madrillet, F-76800 St Etienne Du Rouvray - France

^[3] Univ Rouen, CNRS, Normandie Univ, CORIA UMR 6614, Campus Univ Madrillet, F-76800 St Etienne Du Rouvray - France

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER; v. 218, p. 100-114, OCT 2018.
• Citações Web of Science: 7

Resumo

When dealing with T-matrix methods for structured beams, e.g. Generalized Lorenz-Mie Theories (GLMTs) or Extended Boundary Condition Method (EBCM), the description of the illuminating beam is encoded by a set of coefficients named Beam Shape Coefficients (BSCs). An efficient method to evaluate the BSCs is by using a localized approximation. In a series of papers, we demonstrated that any existing localized approximation is of limited validity (i) in the case of beams exhibiting a propagation factor of the form exp(ikzcos alpha), in which alpha may be called the axicon angle, such as zeroth-order Bessel beams, or (ii) in the case of beams exhibiting a topological charge term, such as Laguerre-Gauss beams propagating freely in space. In the present paper, we consider the case of Laguerre-Gauss beams focused by a lens which exhibit both an axicon angle and a topological charge, and demonstrate that any existing localized approximation should be used with caution as well in this case in contrast with results, available from the literature, in which an integral localized approximation has been used to evaluate the BSCs of such beams. (C) 2018 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 17/10445-0 - Feixes de luz não difrativos microestruturados para micromanipulação óptica
• Beneficiário: Leonardo Andre Ambrosio
• Modalidade de apoio: Auxílio à Pesquisa - Regular