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Upper bounds on focusing efficiency

Schab, Kurt ; Jelinek, Lukas ; Capek, Miloslav and Gustafsson, Mats LU orcid (2022) In Optics Express 30(25). p.45705-45723
Abstract

Upper bounds on the focusing efficiency of aperture fields and lens systems are formulated using integral equation representations of Maxwell’s equations and Lagrangian duality. Two forms of focusing efficiency are considered based on lens exit plane fields and optimal polarization currents within lens design regions of prescribed shape and available materials. Bounds are compared against the performance of classical prescriptions of ideal lens aperture fields, hyperbolic lens designs, and lenses produced by inverse design. Results demonstrate that, without regularization, focusing efficiency based solely on lens exit plane fields is unbounded, similar to the problem of unbounded antenna directivity. Additionally, results considering... (More)

Upper bounds on the focusing efficiency of aperture fields and lens systems are formulated using integral equation representations of Maxwell’s equations and Lagrangian duality. Two forms of focusing efficiency are considered based on lens exit plane fields and optimal polarization currents within lens design regions of prescribed shape and available materials. Bounds are compared against the performance of classical prescriptions of ideal lens aperture fields, hyperbolic lens designs, and lenses produced by inverse design. Results demonstrate that, without regularization, focusing efficiency based solely on lens exit plane fields is unbounded, similar to the problem of unbounded antenna directivity. Additionally, results considering extruded two-dimensional dielectric geometries driven by out-of-plane electric fields for the calculation of bounds and inverse design demonstrate that aperture fields based on time-reversal do not necessarily yield optimal lens focusing efficiency, particularly in the case of near-field (high numerical aperture) focusing.

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Please use this url to cite or link to this publication:
author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Optics Express
volume
30
issue
25
pages
19 pages
publisher
Optical Society of America
external identifiers
  • pmid:36522970
  • scopus:85144165825
ISSN
1094-4087
DOI
10.1364/OE.472558
language
English
LU publication?
yes
id
4f86923a-a906-42cf-9c1e-b9b2305b6fd5
date added to LUP
2023-01-16 08:52:54
date last changed
2024-04-03 18:01:23
@article{4f86923a-a906-42cf-9c1e-b9b2305b6fd5,
  abstract     = {{<p>Upper bounds on the focusing efficiency of aperture fields and lens systems are formulated using integral equation representations of Maxwell’s equations and Lagrangian duality. Two forms of focusing efficiency are considered based on lens exit plane fields and optimal polarization currents within lens design regions of prescribed shape and available materials. Bounds are compared against the performance of classical prescriptions of ideal lens aperture fields, hyperbolic lens designs, and lenses produced by inverse design. Results demonstrate that, without regularization, focusing efficiency based solely on lens exit plane fields is unbounded, similar to the problem of unbounded antenna directivity. Additionally, results considering extruded two-dimensional dielectric geometries driven by out-of-plane electric fields for the calculation of bounds and inverse design demonstrate that aperture fields based on time-reversal do not necessarily yield optimal lens focusing efficiency, particularly in the case of near-field (high numerical aperture) focusing.</p>}},
  author       = {{Schab, Kurt and Jelinek, Lukas and Capek, Miloslav and Gustafsson, Mats}},
  issn         = {{1094-4087}},
  language     = {{eng}},
  month        = {{12}},
  number       = {{25}},
  pages        = {{45705--45723}},
  publisher    = {{Optical Society of America}},
  series       = {{Optics Express}},
  title        = {{Upper bounds on focusing efficiency}},
  url          = {{http://dx.doi.org/10.1364/OE.472558}},
  doi          = {{10.1364/OE.472558}},
  volume       = {{30}},
  year         = {{2022}},
}