Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium

Gashaw Beyene Kassahun

doi:doi:10.11648/j.ajop.20251301.12

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Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium

Gashaw Beyene Kassahun^*

Published in American Journal of Optics and Photonics (Volume 13, Issue 1)

Received: 11 October 2025 Accepted: 21 October 2025 Published: 28 November 2025

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Abstract

In this research work, optical and dispersion responses of bimetallic quantum dot Ag@Au core-shell nanostructures embedded in the non-absorptive host-medium, along with the propagation of slow and fast light waves through these structures, have been investigated. The local field enhancement factor, absorption coefficient, refractive index and group velocity were studied by engineering silver (Ag) as a core and gold (Au) as a shell. The study is based on the quasi-static approximation of classical electrodynamics for composite radii ranging from 6 to 10 nm. Within this quantum dot configuration, two sets of plasmonic resonances were observed in the visible spectral region, corresponding to the two interfaces of the core–shell geometry. The optical properties of the composite were found to depend on factors such as core size, shell thickness, overall composite size, filling factor, and the dielectric function of the host medium. The two plasmonic resonances become closer and more intense as the composite size decreases for a fixed core size, while they shift in opposite directions. Moreover, the resonance peak intensity decreases as the core size increases for a fixed composite size. For optimized core/composite dimensions, shell thickness, and other parameter values, these Ag@Au core–shell nanostructures are promising for diverse applications including photocatalysis, biomedicine, nano-optoelectronics, security technologies, and optical communication.

Published in	American Journal of Optics and Photonics (Volume 13, Issue 1)
DOI	10.11648/j.ajop.20251301.12
Page(s)	17-26
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2025. Published by Science Publishing Group

Keywords

Core-shell, Light Wave, Group Velocity Index, Bimetallic, Enhancement Factor, Dielectrics Function

References

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Kassahun, G. B. (2025). Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium. American Journal of Optics and Photonics, 13(1), 17-26. https://doi.org/10.11648/j.ajop.20251301.12

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ACS Style

Kassahun, G. B. Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium. Am. J. Opt. Photonics 2025, 13(1), 17-26. doi: 10.11648/j.ajop.20251301.12

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AMA Style

Kassahun GB. Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium. Am J Opt Photonics. 2025;13(1):17-26. doi: 10.11648/j.ajop.20251301.12

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@article{10.11648/j.ajop.20251301.12,
  author = {Gashaw Beyene Kassahun},
  title = {Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium},
  journal = {American Journal of Optics and Photonics},
  volume = {13},
  number = {1},
  pages = {17-26},
  doi = {10.11648/j.ajop.20251301.12},
  url = {https://doi.org/10.11648/j.ajop.20251301.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajop.20251301.12},
  abstract = {In this research work, optical and dispersion responses of bimetallic quantum dot Ag@Au core-shell nanostructures embedded in the non-absorptive host-medium, along with the propagation of slow and fast light waves through these structures, have been investigated. The local field enhancement factor, absorption coefficient, refractive index and group velocity were studied by engineering silver (Ag) as a core and gold (Au) as a shell. The study is based on the quasi-static approximation of classical electrodynamics for composite radii ranging from 6 to 10 nm. Within this quantum dot configuration, two sets of plasmonic resonances were observed in the visible spectral region, corresponding to the two interfaces of the core–shell geometry. The optical properties of the composite were found to depend on factors such as core size, shell thickness, overall composite size, filling factor, and the dielectric function of the host medium. The two plasmonic resonances become closer and more intense as the composite size decreases for a fixed core size, while they shift in opposite directions. Moreover, the resonance peak intensity decreases as the core size increases for a fixed composite size. For optimized core/composite dimensions, shell thickness, and other parameter values, these Ag@Au core–shell nanostructures are promising for diverse applications including photocatalysis, biomedicine, nano-optoelectronics, security technologies, and optical communication.},
 year = {2025}
}

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TY  - JOUR
T1  - Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium
AU  - Gashaw Beyene Kassahun
Y1  - 2025/11/28
PY  - 2025
N1  - https://doi.org/10.11648/j.ajop.20251301.12
DO  - 10.11648/j.ajop.20251301.12
T2  - American Journal of Optics and Photonics
JF  - American Journal of Optics and Photonics
JO  - American Journal of Optics and Photonics
SP  - 17
EP  - 26
PB  - Science Publishing Group
SN  - 2330-8494
UR  - https://doi.org/10.11648/j.ajop.20251301.12
AB  - In this research work, optical and dispersion responses of bimetallic quantum dot Ag@Au core-shell nanostructures embedded in the non-absorptive host-medium, along with the propagation of slow and fast light waves through these structures, have been investigated. The local field enhancement factor, absorption coefficient, refractive index and group velocity were studied by engineering silver (Ag) as a core and gold (Au) as a shell. The study is based on the quasi-static approximation of classical electrodynamics for composite radii ranging from 6 to 10 nm. Within this quantum dot configuration, two sets of plasmonic resonances were observed in the visible spectral region, corresponding to the two interfaces of the core–shell geometry. The optical properties of the composite were found to depend on factors such as core size, shell thickness, overall composite size, filling factor, and the dielectric function of the host medium. The two plasmonic resonances become closer and more intense as the composite size decreases for a fixed core size, while they shift in opposite directions. Moreover, the resonance peak intensity decreases as the core size increases for a fixed composite size. For optimized core/composite dimensions, shell thickness, and other parameter values, these Ag@Au core–shell nanostructures are promising for diverse applications including photocatalysis, biomedicine, nano-optoelectronics, security technologies, and optical communication.
VL  - 13
IS  - 1
ER  -

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Author Information

Gashaw Beyene Kassahun

Applied Physics Program, Adama Science and Technology University, Adama, Ethiopia

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http://orcid.org/0000-0002-5065-3494

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APA Style

Kassahun, G. B. (2025). Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium. American Journal of Optics and Photonics, 13(1), 17-26. https://doi.org/10.11648/j.ajop.20251301.12

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ACS Style

Kassahun, G. B. Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium. Am. J. Opt. Photonics 2025, 13(1), 17-26. doi: 10.11648/j.ajop.20251301.12

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AMA Style

Kassahun GB. Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium. Am J Opt Photonics. 2025;13(1):17-26. doi: 10.11648/j.ajop.20251301.12

Copy | Download

@article{10.11648/j.ajop.20251301.12,
  author = {Gashaw Beyene Kassahun},
  title = {Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium},
  journal = {American Journal of Optics and Photonics},
  volume = {13},
  number = {1},
  pages = {17-26},
  doi = {10.11648/j.ajop.20251301.12},
  url = {https://doi.org/10.11648/j.ajop.20251301.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajop.20251301.12},
  abstract = {In this research work, optical and dispersion responses of bimetallic quantum dot Ag@Au core-shell nanostructures embedded in the non-absorptive host-medium, along with the propagation of slow and fast light waves through these structures, have been investigated. The local field enhancement factor, absorption coefficient, refractive index and group velocity were studied by engineering silver (Ag) as a core and gold (Au) as a shell. The study is based on the quasi-static approximation of classical electrodynamics for composite radii ranging from 6 to 10 nm. Within this quantum dot configuration, two sets of plasmonic resonances were observed in the visible spectral region, corresponding to the two interfaces of the core–shell geometry. The optical properties of the composite were found to depend on factors such as core size, shell thickness, overall composite size, filling factor, and the dielectric function of the host medium. The two plasmonic resonances become closer and more intense as the composite size decreases for a fixed core size, while they shift in opposite directions. Moreover, the resonance peak intensity decreases as the core size increases for a fixed composite size. For optimized core/composite dimensions, shell thickness, and other parameter values, these Ag@Au core–shell nanostructures are promising for diverse applications including photocatalysis, biomedicine, nano-optoelectronics, security technologies, and optical communication.},
 year = {2025}
}

Copy | Download

TY  - JOUR
T1  - Optical Response and Light Propagation in Bimetallic Quantum Dot Ag@Au Core-shell Nanocomposite Embedded in Non-absorptive Host Medium
AU  - Gashaw Beyene Kassahun
Y1  - 2025/11/28
PY  - 2025
N1  - https://doi.org/10.11648/j.ajop.20251301.12
DO  - 10.11648/j.ajop.20251301.12
T2  - American Journal of Optics and Photonics
JF  - American Journal of Optics and Photonics
JO  - American Journal of Optics and Photonics
SP  - 17
EP  - 26
PB  - Science Publishing Group
SN  - 2330-8494
UR  - https://doi.org/10.11648/j.ajop.20251301.12
AB  - In this research work, optical and dispersion responses of bimetallic quantum dot Ag@Au core-shell nanostructures embedded in the non-absorptive host-medium, along with the propagation of slow and fast light waves through these structures, have been investigated. The local field enhancement factor, absorption coefficient, refractive index and group velocity were studied by engineering silver (Ag) as a core and gold (Au) as a shell. The study is based on the quasi-static approximation of classical electrodynamics for composite radii ranging from 6 to 10 nm. Within this quantum dot configuration, two sets of plasmonic resonances were observed in the visible spectral region, corresponding to the two interfaces of the core–shell geometry. The optical properties of the composite were found to depend on factors such as core size, shell thickness, overall composite size, filling factor, and the dielectric function of the host medium. The two plasmonic resonances become closer and more intense as the composite size decreases for a fixed core size, while they shift in opposite directions. Moreover, the resonance peak intensity decreases as the core size increases for a fixed composite size. For optimized core/composite dimensions, shell thickness, and other parameter values, these Ag@Au core–shell nanostructures are promising for diverse applications including photocatalysis, biomedicine, nano-optoelectronics, security technologies, and optical communication.
VL  - 13
IS  - 1
ER  -

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