scholarly journals Optical properties of gold nanorods macro-structure: a numerical study

2017 ◽  
Vol 9 (1) ◽  
pp. 23 ◽  
Author(s):  
Arthur Gontier ◽  
J. Marae-Djouda ◽  
R. Caputo ◽  
Y. Madi ◽  
M. Molinari ◽  
...  

In this contribution, a numerical study of the optical properties of closely-packed gold nanorods was performed. The studied nano-objects are experimentally grown on a tilted polydimethylsiloxane (PDMS) substrate by using physical vapor deposition (PVD). This method creates nanorods tilted to a certain angle with respect to the substrate normal. This geometry allows exciting both transverse and longitudinal modes of the rods. As demonstrated in a previous experimental work, such PVD-grown nano-objects show promising possibilities both as strain gauges or strain-tunable metamaterials if fabricated on a stretchable dielectric substrate. This numerical study is based on experimental data from previous work and pushes further the subject by approaching an optimized nano-structure allowing better strain-sensitivity (particularly by changing the auto-organization of the said nanorods). Full Text: PDF ReferencesJ.W.M. Chon, C. Bullen, P. Zijlstra, M. Gu, "Spectral encoding on Gold Nanorods Doped in a Silica Sol?Gel Matrix and Its Application to High-Density Optical Data Storage", Adv. Funct. Mater. 17, 875 (2007). CrossRef C.-C. Chen, Y.-P. Lin, C.-W. Wang, H.-C. Tzeng, C.-H. Wu, Y.-C. Chen, C.-P. Chen, L.-C. Chen, Y.-C. Wu, "DNA?Gold Nanorod Conjugates for Remote Control of Localized Gene Expression by near Infrared Irradiation", J. Am. Chem. Soc. 128, 3709 (2006). CrossRef J.N. Anker, W.P. Hall, O. Lyandres, N.C. Shah, J. Zhao, R.P. Van Duyne, "Biosensing with plasmonic nanosensors", Nat. Mater 7, 442 (2008). CrossRef B. Sepulveda, P.C. Angelome, L.M. Lechuga, L.M. Liz-Marzan?, "LSPR-based nanobiosensors", Nano Today 4, 244 (2009). CrossRef A. Haes, R.P. Van Duyne, "A Nanoscale Optical Biosensor: Sensitivity and Selectivity of an Approach Based on the Localized Surface Plasmon Resonance Spectroscopy of Triangular Silver Nanoparticles", J. Am. Chem. Soc. 124, 10596 (2002). CrossRef J.C. Riboh, A.J. Haes, A.D. McFarland, C.R. Yonzon, R.P. Van Duyne, "A Nanoscale Optical Biosensor: Real-Time Immunoassay in Physiological Buffer Enabled by Improved Nanoparticle Adhesion", J. Phys. Chem. B 107, 1772 (2003). CrossRef C.R. Yonzon, E. Jeoung, S. Zou, G.C. Schatz, M. Mrksich, R.P. Van Duyne, "A Comparative Analysis of Localized and Propagating Surface Plasmon Resonance Sensors: The Binding of Concanavalin A to a Monosaccharide Functionalized Self-Assembled Monolayer", J. Am. Chem. Soc. 126, 12669 (2004). CrossRef A.J. Haes, L. Chang, W.L. Klein, R.P. Van Duyne, "Detection of a Biomarker for Alzheimer's Disease from Synthetic and Clinical Samples Using a Nanoscale Optical Biosensor", J. Am. Chem. Soc. 127, 2264 (2005). CrossRef R. Caputo, G. Palermo, M.Infusino L. De Sio, "Liquid Crystals as an Active Medium: Novel Possibilities in Plasmonics", Nanospectroscopy 1, 40 (2015). CrossRef T. Maurer, J. Marae-Djouda, U. Cataldi, A. Gontier, G. Montay, Y. Madi, B. Panicaud, D. Macias, P.-M. Adam, G. Lév?que, T. Bürgi, R. Caputo, "The beginnings of plasmomechanics: towards plasmonic strain sensors", Frontiers of Materials Science 9, 170 (2015). CrossRef X. Niu, S. P. Stagon, H. Huang, J.K. Baldwin, A. Misra, "Smallest Metallic Nanorods Using Physical Vapor Deposition", Phys. Rev. Lett. 110 136102 (2013). CrossRef Lumerical Solutions, Inc. DirectLink P.K. Jain, W. Huang, M.A.El-Sayed, "On the Universal Scaling Behavior of the Distance Decay of Plasmon Coupling in Metal Nanoparticle Pairs: A Plasmon Ruler Equation", Nanoletters 7, 2080 (2007). CrossRef P.K. Jain, M.A. El-Sayed, "Plasmonic coupling in noble metal nanostructures", Chem. Phys. Letters 487, 153 (2010). CrossRef

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1728
Author(s):  
Joshua Fernandes ◽  
Sangmo Kang

The near-field enhancement and localized surface plasmon resonance (LSPR) on the core-shell noble metal nanostructure surfaces are widely studied for various biomedical applications. However, the study of the optical properties of new plasmonic non-spherical nanostructures is less explored. This numerical study quantifies the optical properties of spherical and non-spherical (prolate and oblate) dimer nanostructures by introducing finite element modelling in COMSOL Multiphysics. The surface plasmon resonance peaks of gold nanostructures should be understood and controlled for use in biological applications such as photothermal therapy and drug delivery. In this study, we find that non-spherical prolate and oblate gold dimers give excellent tunability in a wide range of biological windows. The electromagnetic field enhancement and surface plasmon resonance peak can be tuned by varying the aspect ratio of non-spherical nanostructures, the refractive index of the surrounding medium, shell thickness, and the distance of separation between nanostructures. The absorption spectra exhibit considerably greater dependency on the aspect ratio and refractive index than the shell thickness and separation distance. These results may be essential for applying the spherical and non-spherical nanostructures to various absorption-based applications.


2014 ◽  
Vol 602-603 ◽  
pp. 993-997
Author(s):  
Gui Jun Ban ◽  
Xiu Li Fu ◽  
Zhi Jian Peng

Gold nanorods with different aspect ratios, exhibiting localized surface plasmon resonance in a tuned longitudinal mode, were prepared by employing a seed mediated growth approach. Their third-order nonlinear optical properties were investigated by using femtosecond Z-scan technique at 800 nm. All the prepared gold nanorods with different aspect ratios exhibited a reverse saturation absorbance behavior, and the value of effective nonlinear absorption coefficient reaches its maximum when the longitudinal surface plasmon resonance peak of the gold nanorods located near the excitation wavelength.


Photonics ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 41
Author(s):  
Najat Andam ◽  
Siham Refki ◽  
Hidekazu Ishitobi ◽  
Yasushi Inouye ◽  
Zouheir Sekkat

The determination of optical constants (i.e., real and imaginary parts of the complex refractive index (nc) and thickness (d)) of ultrathin films is often required in photonics. It may be done by using, for example, surface plasmon resonance (SPR) spectroscopy combined with either profilometry or atomic force microscopy (AFM). SPR yields the optical thickness (i.e., the product of nc and d) of the film, while profilometry and AFM yield its thickness, thereby allowing for the separate determination of nc and d. In this paper, we use SPR and profilometry to determine the complex refractive index of very thin (i.e., 58 nm) films of dye-doped polymers at different dye/polymer concentrations (a feature which constitutes the originality of this work), and we compare the SPR results with those obtained by using spectroscopic ellipsometry measurements performed on the same samples. To determine the optical properties of our film samples by ellipsometry, we used, for the theoretical fits to experimental data, Bruggeman’s effective medium model for the dye/polymer, assumed as a composite material, and the Lorentz model for dye absorption. We found an excellent agreement between the results obtained by SPR and ellipsometry, confirming that SPR is appropriate for measuring the optical properties of very thin coatings at a single light frequency, given that it is simpler in operation and data analysis than spectroscopic ellipsometry.


2011 ◽  
Vol 22 (26) ◽  
pp. 265705 ◽  
Author(s):  
S L Smitha ◽  
K G Gopchandran ◽  
T R Ravindran ◽  
V S Prasad

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