Hi Neils,
I think it is not only the resolution,
but also the Courant factor should be adjusted when working with the dispersive
medium.
I
don't know which value of the Courant factor is good, but you can try to adjust
it in your script.
Best
regard,
P.
Tapsanit
Department
of Physics,
Tohoku
university, Japan.
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Today's Topics:
1. Resolution dependence silver nanosphere (niels jelsma)
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Message: 1
Date: Wed, 29 May 2013 13:23:20 +0200
From: niels jelsma <[email protected]>
To: [email protected]
Subject: [Meep-discuss] Resolution dependence silver nanosphere
Message-ID: <[email protected]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Dear All,
I'm trying to calculate the dipolemoment of a silver nanosphere in Meep.
In the end I am interested in looking at a chain of spheres and the
transmittance, p_last / p_first.
However for just a single sphere I don't understand what values I have
to choose for the resolution to get proper results.
I've read on the mailing list that I should choose a resolution that
gives at least 8pixels/wavelength and then double the resolution to get
better results.
However, increasing the resolution this way sometimes gives me worse
results.
A simplified version of my script can be found here:
https://gist.github.com/maxnuf/5669273
I've setup a sphere with radius 25nm in 3d space and a continuous source
as plane-wave.
After running it for a while to get into a steady-state I integrate the
Polarization in a volume containing the sphere to find the dipolemoment.
I expect to find a peak near the resonant frequency. So I run the
simulation for several input source wavelengths.
However, for different resolutions, I get completely different results.
I don't know what to do to remedy my problem.
As can be seen in this figure:
http://postimg.org/image/kua54kwq9/
At a resolution 32 I see a sort of dip where I expect the resonant
frequency (which should be at 363nm according to Mie theory)
I'm using Meep 1.2 and a Drude-model for my silver sphere.
How can I determine which resolutions are suitable?
Thanks,
Niels
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