Electric Field in Metal Nanoparticle Dimers

Posted on Sat 09 April 2011 in Plasmonics • Tagged with FDTD, Molecular Machines, photonics, Plasmonics, SERS

Metal nanoparticles exhibit localized surface plasmon resonance (LSPR). One can think of LSPR as resonance of electron sea oscillations driven by incident electric field. This is similar to the way a spring-mass system attains resonance under external periodic driving force.

The result of this plasmon resonance is enhanced dipole moment …


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Charge density in metal nanoparticles at plasmon resonance

Posted on Tue 23 November 2010 in Plasmonics • Tagged with electromagnetism, FDTD, Free Software, photonics, Plasmonics

It is important to know the magnitude and distribution of electric field near the metallic nanoparticles at plasmon resonance. One can look at the electric field and say whether the plasmon mode is dipolar or higher order mode such as qudrapolar mode. At many times one is also interested to …


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Spoof Plasmons / Designer Surface Plasmons

Posted on Thu 07 October 2010 in Plasmonics • Tagged with MEEP, FDTD

Aim of this article/post: To 1) introduce the concept of Designer surface plasmons or Spoof plasmons and 2) Dispersion relations and Visualization of the fields using MEEP code. (Some of the text/simulations are taken from my paper in the area of DSPs.)

Surface Plasmons are electromagnetic waves that …


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DDSCAT and electric field at plasmon resonance

Posted on Wed 26 May 2010 in Plasmonics • Tagged with DDSCAT, electromagnetism, Free Software, Plasmonics

Discrete Dipole Approximation (DDA) is an important tool in plasmonics research. Using DDA, one can calculate scattering properties of nanoparticles at various wavelengths, polarizations and surrounding medium. The specialty of DDA is that one can calculate scattering properties of irregular shape particles (particles other than spheroids). DDA is based on …


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Nmie: Extinction, Scattering and Absorption efficiencies of multilayer nanoparticles

Posted on Tue 11 May 2010 in Plasmonics • Tagged with electromagnetism, Free Software, Nanohub.org, Plasmonics, DDSCAT

nmie tool on Nanohub.org. This tool calculates the extinction, scattering, and absorption efficiencies of single nanoparticle (1 layer),core-shell nanoparticle (2 layer) and nanomatryushka nanoparticle (3 layer) using MIE formulation.

Since 2009, I have been a regular user of Nanohub.org. www.Nanohub.orgis a website that provides …


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WINSPALL software for surface plasmon resonance experiments

Posted on Wed 10 March 2010 in Plasmonics • Tagged with electromagnetism, Free Software, photonics, Plasmonics

One needs to fit the reflectivity curves obtained in surface plasmon resonance experiments with theoretical models. A free software (for non commercial use) called Winspall exactly does that.

According to the developers, WINSPALL is a PC based software which computes the reflectivity of optical multilayer systems. It is based on …


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Radiation from an oscillating dipole

Posted on Thu 14 January 2010 in Plasmonics • Tagged with electromagnetism, Matlab, Plasmonics

The electric field from an oscillating dipole is given by:, where [tex]\hat{r}[/tex] is the position vector, [tex] \omega [/tex] is the frequency of dipole oscillation, [tex]\textbf{p}[/tex] is the dipole moment. The two terms in the electric field consists of 1) near field (area near …


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Resources on Electromagnetics/Plasmonics/Nanophotonics

Posted on Tue 12 January 2010 in Plasmonics • Tagged with books, electromagnetism, FDTD, Free Software, Nanohub.org, photonics, Plasmonics

These are some resources on Electromagnetics/plasmonics/nanophotonics

I will maintain a list of free resources on electromagnetics, plasmonics, nanophotonics, optics and other related topics here. If any of you (readers) know any other free resources related to this topic, please let me know and I can add into these …


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Surface Plasmons (SP's)

Posted on Fri 08 January 2010 in Plasmonics • Tagged with animation, Plasmonics

[caption id="attachment_263" align="aligncenter" width="300"] Propagation of surface plasmons[/caption]

Surface plasmons (SP's) are electromagnetic waves that propagate at the interface between metals (such as Ag, Au ) and dielectric material. Here I have simulated the propagation of surface plasmons on Ag-air interface, the color indicates the magnitude of …


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Plasmonic coupling of electromagnetic energy in hexagonal array of silver nanorods

Posted on Fri 08 January 2010 in Plasmonics • Tagged with FDTD, MEEP, Plasmonics

A cool animation which I reproduced from W.M Saj, Optics Express, Vol 13, 13, 2005 using freely obtained FDTD software (MEEP). It demonstrates the propagation of electromagnetic energy in hexagonal array of silver nanorods due to plasmonic coupling. The source is offset from the center and the energy is …


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