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How to active inner boundary?

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Dear all,


I am stuck when I build the plasmonic grating model based on the "plasmonic wire graring" model
Now I would like to add two PML layers on the top and bottom,respectively.
However, you know, when the PMLs are added, all the inner boundaries are unavailable for the definition of any BC.
I would calculate the transmission and reflection, so how can I define the Port BC?

Million thanks!

3 Replies Last Post 01.05.2012, 20:48 GMT-4

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Posted: 1 decade ago 01.05.2012, 15:57 GMT-4
You can't use PMLs with Port BCs. But Port BCs are transparent to specified plain waves so you don't really need PMLs.
You can't use PMLs with Port BCs. But Port BCs are transparent to specified plain waves so you don't really need PMLs.

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Posted: 1 decade ago 01.05.2012, 18:15 GMT-4
Thanks for your reply!

Actually I faced the same problem described here

www.comsol.com/community/forums/general/thread/27642/

So I would like to add PMLs to absorb the light.

According to the model of "plasmonic wire grating", does it mean we should define lots of PORT BCs to absorb the light?




Thanks for your reply! Actually I faced the same problem described here http://www.comsol.com/community/forums/general/thread/27642/ So I would like to add PMLs to absorb the light. According to the model of "plasmonic wire grating", does it mean we should define lots of PORT BCs to absorb the light?

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Posted: 1 decade ago 01.05.2012, 20:48 GMT-4
Yes. If you use plane wave illumination, then you need to define one port BC per each diffraction order. Based on wavelength, grating period and angle of incidence, you can calculate which diffraction order you will have.
Yes. If you use plane wave illumination, then you need to define one port BC per each diffraction order. Based on wavelength, grating period and angle of incidence, you can calculate which diffraction order you will have.

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