It's hard to guess what might be going wrong without any details. Are
you simulating material dispersion? It's easy to mess up the
polarizability parameters and get nonsense results. If your scatterer
is lossless, what kind of loss values do you compute when you compare
the transmission and reflection fluxes?
On Wed, 6 Aug 2008, Minh Nguyen Huu wrote:
>
> Hi,
>
> Thanks for the speedy reply. The structure I'm trying to simulate is a
> 2D SOI waveguide. I am interested to see how much light is reflected
> if I end it abruptly in air. I made sure my PML layer is thick enough
> (equal to the longest wavelength) and I also placed the flux planes
> far enough from the source and scatterer (2.5 and 3.5 units
> respectively, longest wavelength being 1.83). I also tried using a
> smaller spectrum, but I'm still getting nonsensical values.
>
> Short of some scripting error on my part, is there anything else I can
> try?
>
> Kind regards,
>
> Minh
>
>
>> Date: Tue, 5 Aug 2008 15:12:05 +0200
>> From: [EMAIL PROTECTED]
>> To: [EMAIL PROTECTED]
>> CC: [email protected]
>> Subject: Re: [Meep-discuss] Reflection calculation
>>
>>
>>
>>
>> Start off by making sure your flux planes are at least a wavelength (the
>> longest one) away from the source plane or PML. Also make sure that
>> the flux planes are a wavelength away from the scatterer.
>>
>> Make sure your PML is thick enough (one wavelength is safe).
>>
>> If your structure is very resonant, it can trap energy and lead to
>> strange scattering values as well. Make sure you let the simulation run
>> long enough by using the stop-when-fields-decayed feature. It may also
>> help to use a more narrowband excitation.
>>
>> Hopefully that corrects it for you. If the simulation time becomes too
>> long, you can try to gradually reduce all of those distances until the
>> point where those errors become significant.
>>
>> Best,
>> Matt
>>
>>
>>
>>
>> On Tue, 5 Aug 2008, Minh Nguyen Huu wrote:
>>
>>>
>>> Hi,
>>>
>>> I've ran into a strange problem when trying to calculate the
>>> reflection spectrum of the structure I'm trying to simulate. What I
>>> find is that for some frequencies the calculated values (after the
>>> second run with the reflector) are positive. The script I made is just
>>> a modified version of the script found on the website. If anybody ever
>>> ran into this problem or can direct me to an email where this problem
>>> has already been discussed, I would be very grateful.
>>>
>>> Kind regards,
>>>
>>> Minh
>>> _________________________________________________________________
>>> Jouw nieuws en entertainment, vind je op MSN.nl!
>>> http://nl.msn.com/
>
> _________________________________________________________________
> De leukste online filmpjes vind je op MSN Video!
> http://video.msn.com/video.aspx?mkt=nl-nl
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