Particles scatter and absorb electromagnetic radiation. One often needs to compare the amount of scattering/absorption/extinction for particles of different shapes, composition, sizes and incident light properties (polarization, frequency and angle). In this regard, the concept of cross-sections comes into picture. There are three types of cross-sections, 1) scattering …

Continue reading

In MEEP (1.1.1), dielectric structures are often created by constructive geometry (adding and subtracting primitive shapes). The primitive shapes that are allowed are blocks, cylinders, ellipsoids and cones. To create a complex shape, one has to decompose the geometry into these primitive shapes. Over the weekend, I was …

Continue reading

[latexpage]

The aim of this post is to share my experience in incorporating dielectric function of metals such as gold and silver into MEEP (a free finite difference time domain package) code. The incorporation is not an easy task and can be daunting for the first time user.

Metals such …

Continue reading

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 …

Continue reading

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 …

Continue reading

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 …

Continue reading

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 …

Continue reading