DDSCAT and electric field at plasmon resonance

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 representing a particle into a Read More …

Nmie: Extinction, Scattering and Absorption efficiencies of multilayer nanoparticles

Since 2009, I have been a regular user of Nanohub.org. www.Nanohub.org is a website that provides a platform for online simulation, research and teaching resources. Of interest is the ability to perform simulation online without installing software on your local computer. I envision that this type of cloud computing model will be the future of Read More …

WINSPALL software for surface plasmon resonance experiments

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 the Fresnel equations and the Read More …

Dynamic Exciton-Plasmon Coupling

Our paper titled “Dynamically Tuning Plasmon-Exciton Coupling in Arrays of Nanodisk-J-aggregate Complexes” has been accepted as front cover image of Advanced Materials . In this work, we demonstrated the dynamic tuning of plasmon-exciton resonant coupling in arrays of nanodisk–J-aggregate complexes. The angle-resolved spectra of an array of bare Au nanodisks exhibited continuous shifting of localized Read More …

Radiation from an oscillating dipole

The electric field from an oscillating dipole is given by:, where is the position vector, is the frequency of dipole oscillation, is the dipole moment. The two terms in the electric field consists of 1) near field (area near to the dipole) and 2) far field (area far from the dipole) contributions. Far field falls Read More …

Resources on Electromagnetics/Plasmonics/Nanophotonics

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 lists. Free books: Electromagnetic waves and Antennas Read More …

Simulation of Localized surface plasmons

A cool simulation using FDTD showing the excitaion of Localized Surface Plasmons in metal nanorods. These simulations are done by Prof. Maxim Sukhrev. The external electromagnetic wave excites plasmons (oscillation of electron sea in the particle) in the direction of polarization of incident wave. At a certain resonance frequency of incoming light (which depends on Read More …

Surface Plasmons (SP’s)

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 electric field (blue for positive and red for negative).  I have used MEEP  (a FDTD program Read More …

Plasmonic coupling of electromagnetic energy in hexagonal array of silver nanorods

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 propagated in an interesting snake like Read More …