Recent content by Srbasket

This might help, it is under construction, but... srdjancomsol.weebly.com

Hi, go for RF module. You should be able to download example of Mie scattering calculations from comsol website. That is very good starting point. Also there are many more models that might be usefull. You should also read carefully all the posts. Check also Discussion on comsol web site, and...

Hi, all, just to update this post. We have been checking if SC gives similar result to Green dyiadic method for substrate case, and the found resonance by both methods coincide pretty much. However, it looks like for anything else, like radiation pattern calculations, or real physical values of...

Hi, all, Thanks to my good friend V, I am able to update u all about COMSOL issues related to nanoparticles. There is a mistake that I and many more were doing. If you take a look at Stratton-Chu formulae that is implemented directly in comsol, you will notice that it works only for scatterer...

Hi, all, I have compared 2-step procedure with 1-step procedure, and results are the same, so don't do 2 step procedure if you are solving for SCATTERED FIELD. I am planning to compare 1-step procedure where Solving for scattered field, and 2-step procedure when solving for total field...

Last update: If you don´t have COMSOL 3.5a with installed patch, just forget about solving for scatered field (scatered harmonic propagation in RF module)... Just got Comsol 3.5a, and default PMLs work very good. No more weird reflections, near field looks very neat... Cheers

IMPORTANT Update regarding this post: It looks like COMSOL has problems regarding PMLs performance for versions older than COMSOL 3.5a+patch. I made geometry as always in scattering formulation (solving for scE), all air and PML, and have launched plane wave with amplitude 1 V/m. Scatered...

I put my structures directly on the substrate, but my structures are flat cylindars, in case of spheres might be a problem, but if you mesh it nicely might work. What you get depends on if are you solving for scattered field or total field, how did you defined excitation and similar. If u...

With my machine to solve model of 200.000 elements it takes around 35min for 2 step procedure (2 solver runs, GMRES), where Stratton-Chu integration is part of second solver run, so I imagine it takes less than few minutes, but again depends on number of mesh elements that your sphere is...

Not particles of that size, but they behave in expected way. For instance Bulk refractive index sensitivity is more-less expected. I did long time ago for the bigger cylinders that I fabricate, and it fitted well. I can try again. Anyway, it looks like one have to optimize PML and meshing to...

One clarification: In 3) second time you are solving press RESTART, not the SOLVE

This is how it looks. Cylindar made of gold, 50nm diameter, 10nm height, laying on glass substrate... Integration sphere for Straton-Chu was placed on 175nm from the center... That is the one geometry that worked fine in my case...Spectra are in case of air, water and dielectric of 1.517 ref...

Hi, all, folks keep contacting me about different things regarding this subject. I have advanced a bit, but still some issues remaining. 1) In excitation field definition you can forget about using complicated formulae with different expressions for z>0 and z<0. It looks like that if u use...

I´ll try to explain. When I keep my excitation as exp(-j*k0_rfw*z) it works fine for vacuum medium. But in medium with ref. index of n, you have to define it as exp(-j*k0_rfw*n*z). If u have different media in your model, for example substrate and air, you have to define it in each subdomain...

Yes, one frequency at time since COMSOL is FEM. (U may try with some software based on FDTD method, it's faster but with some drawbacks)... Well, I am doing the same, scattering of metallic particles, and it works fine if u calculate spectra of particles in uniform medium, but if there is some...