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Nanocolumnar Metamaterial Platforms : Scaling Rules for Structural Parameters Revealed from Optical Anisotropy

Kilic, Ufuk ; Traouli, Yousra ; Hilfiker, Matthew ; Bryant, Khalil ; Schoeche, Stefan ; Feder, Rene ; Argyropoulos, Christos ; Schubert, Eva and Schubert, Mathias LU orcid (2024) In Advanced Optical Materials 12(30).
Abstract

Nanostructures represent a frontier where meticulous attention to the control and assessment of structural dimensions becomes a linchpin for their seamless integration into diverse technological applications. However, determining the critical dimensions and optical properties of nanostructures with precision still remains a challenging task. In this study, by using an integrative and comprehensive methodical series of studies, the evolution of the depolarization factors in the anisotropic Bruggeman effective medium approximation (AB-EMA) is investigated. It is found that these anisotropic factors are extremely sensitive to the changes in critical dimensions of the nanostructure platforms. In order to perform a systematic... (More)

Nanostructures represent a frontier where meticulous attention to the control and assessment of structural dimensions becomes a linchpin for their seamless integration into diverse technological applications. However, determining the critical dimensions and optical properties of nanostructures with precision still remains a challenging task. In this study, by using an integrative and comprehensive methodical series of studies, the evolution of the depolarization factors in the anisotropic Bruggeman effective medium approximation (AB-EMA) is investigated. It is found that these anisotropic factors are extremely sensitive to the changes in critical dimensions of the nanostructure platforms. In order to perform a systematic characterization of these parameters, spatially coherent, highly-ordered slanted nanocolumns are fabricated from zirconia, silicon, titanium, and permalloy on silicon substrates with varying column lengths using glancing angle deposition (GLAD). In tandem, broad-spectral range Mueller matrix spectroscopic ellipsometry data, spanning from the near-infrared to the vacuum UV (0.72–6.5 eV), is analyzed with a best-match model approach based on the anisotropic Bruggeman effective medium theory. The anisotropic optical properties, including complex dielectric function, birefringence, and dichroism, are thereby extracted. Most notably, the research unveils a generalized, material-independent inverse relationship between depolarization factors and column length. It is envisioned that the presented scaling rules will permit accurate prediction of optical properties of nanocolumnar thin films improving their integration and optimization for optoelectronic and photonic device applications. As an outlook, the highly porous nature and extreme birefringence properties of the fabricated columnar metamaterial platforms are further explored in the detection of nanoparticles from the cross-polarized integrated spectral color variations.

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author
; ; ; ; ; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
critical-dimension-analysis, extreme-birefringence and dichroism, glancing angle deposition, nanostructure
in
Advanced Optical Materials
volume
12
issue
30
article number
2302767
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85202974789
ISSN
2195-1071
DOI
10.1002/adom.202302767
language
English
LU publication?
yes
id
d553ded4-871f-41e7-8e0a-058fc46b9a5b
date added to LUP
2024-12-13 14:00:35
date last changed
2025-04-04 15:22:57
@article{d553ded4-871f-41e7-8e0a-058fc46b9a5b,
  abstract     = {{<p>Nanostructures represent a frontier where meticulous attention to the control and assessment of structural dimensions becomes a linchpin for their seamless integration into diverse technological applications. However, determining the critical dimensions and optical properties of nanostructures with precision still remains a challenging task. In this study, by using an integrative and comprehensive methodical series of studies, the evolution of the depolarization factors in the anisotropic Bruggeman effective medium approximation (AB-EMA) is investigated. It is found that these anisotropic factors are extremely sensitive to the changes in critical dimensions of the nanostructure platforms. In order to perform a systematic characterization of these parameters, spatially coherent, highly-ordered slanted nanocolumns are fabricated from zirconia, silicon, titanium, and permalloy on silicon substrates with varying column lengths using glancing angle deposition (GLAD). In tandem, broad-spectral range Mueller matrix spectroscopic ellipsometry data, spanning from the near-infrared to the vacuum UV (0.72–6.5 eV), is analyzed with a best-match model approach based on the anisotropic Bruggeman effective medium theory. The anisotropic optical properties, including complex dielectric function, birefringence, and dichroism, are thereby extracted. Most notably, the research unveils a generalized, material-independent inverse relationship between depolarization factors and column length. It is envisioned that the presented scaling rules will permit accurate prediction of optical properties of nanocolumnar thin films improving their integration and optimization for optoelectronic and photonic device applications. As an outlook, the highly porous nature and extreme birefringence properties of the fabricated columnar metamaterial platforms are further explored in the detection of nanoparticles from the cross-polarized integrated spectral color variations.</p>}},
  author       = {{Kilic, Ufuk and Traouli, Yousra and Hilfiker, Matthew and Bryant, Khalil and Schoeche, Stefan and Feder, Rene and Argyropoulos, Christos and Schubert, Eva and Schubert, Mathias}},
  issn         = {{2195-1071}},
  keywords     = {{critical-dimension-analysis; extreme-birefringence and dichroism; glancing angle deposition; nanostructure}},
  language     = {{eng}},
  number       = {{30}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Advanced Optical Materials}},
  title        = {{Nanocolumnar Metamaterial Platforms : Scaling Rules for Structural Parameters Revealed from Optical Anisotropy}},
  url          = {{http://dx.doi.org/10.1002/adom.202302767}},
  doi          = {{10.1002/adom.202302767}},
  volume       = {{12}},
  year         = {{2024}},
}