Comparison of the shape of focal spots in terms of intensity and energy flux for a high-aperture zone plate and a spiral zone plate

Using a finite-difference time-domain method, it has been shown that focal spots generated when tightly focusing a linearly polarized Gaussian beam by a Fresnel zone plate (FZP) and when focusing a Gaussian beam with an embedded optical vortex by a spiral zone plate (SZP) have different patterns of...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Kompʹûternaâ optika 2022-08, Vol.46 (4), p.531-536
Hauptverfasser: Savelyeva, A.A., Kozlova, E.S.
Format: Artikel
Sprache:eng ; rus
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:Using a finite-difference time-domain method, it has been shown that focal spots generated when tightly focusing a linearly polarized Gaussian beam by a Fresnel zone plate (FZP) and when focusing a Gaussian beam with an embedded optical vortex by a spiral zone plate (SZP) have different patterns of the intensity and energy flux. The most significant differences are observed when the value of the topological charge (TC) is equal to three. The energy flux has an annular distribution when the Gaussian beam is focused by the FZP, while the SZP produces a field whose patterns of intensity and energy flux have three local maxima. The number of local maxima corresponds to the order of the SZP. At a certain distance from the focus, the petal structure of the intensity (and energy flux) changes to a ring distribution.
ISSN:0134-2452
2412-6179
DOI:10.18287/2412-6179-CO-934