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3D dispersion curves using Comsol

Posted 15 févr. 2011, 05:27 UTC−5 9 Replies

mfarhat
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Dear all,

My problem is very simple: I am trying to compute dispersion curves for a photonic crystal made of dielectric spheres, in 3D using Comsol. But, before I wanted to test the Floquet-Bloch conditions with the dispersion of vacuum, a square cell with eps=mu=1, and F-B conditions on its boundaris (the media is periodic in the three directions). But the problem is that even for this very simple case (eigenmodes are just plane waves!) it seems not working, and the field-map of the electric or magnetic field are like noise....
So did anyone had experience with such calculations (dispersion curves in 3D using the RF-eigenmodes solver of Comsol)?

Thanks in advance for any answer,

best regards,

Mohamed Farhat.
9 Replies Last Post 25 avr. 2017, 11:18 UTC−4
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Hello mfarhat

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Hua Zhang
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Posted: 1 decade ago 22 avr. 2011, 10:11 UTC−4
Dear Mohamed
have you solved your problem yet?
Dear Mohamed have you solved your problem yet?
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 22 avr. 2011, 10:28 UTC−4
Hi

Noisy results, remind me about poorly resolved mesh (w.r.t. 3-5 mesh elements per wavelength in the material criteria) Have you checked that, RF is very mesh density hence ram demanding

--
Good luck
Ivar
Hi Noisy results, remind me about poorly resolved mesh (w.r.t. 3-5 mesh elements per wavelength in the material criteria) Have you checked that, RF is very mesh density hence ram demanding -- Good luck Ivar
Hua Zhang
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Posted: 1 decade ago 22 avr. 2011, 10:46 UTC−4
Dear Ivar:
Could you offer some help for me? I want to calculate the band diagram of 3D structure. I placed a sphere in the center of a cubic. In the boundary setting , I set the Floquet periodicity for all the surface of the cubic and set continue for the sphere. when meshing the structure i choose free meshing paremeters and I remesh it in global tab. But it does not converge.
Thanks for you help.
Hua Zhang
Dear Ivar: Could you offer some help for me? I want to calculate the band diagram of 3D structure. I placed a sphere in the center of a cubic. In the boundary setting , I set the Floquet periodicity for all the surface of the cubic and set continue for the sphere. when meshing the structure i choose free meshing paremeters and I remesh it in global tab. But it does not converge. Thanks for you help. Hua Zhang
Hua Zhang
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Posted: 1 decade ago 22 avr. 2011, 12:37 UTC−4
Could anybody tell me how to mesh the 3D photonic crystal? my structure is a sphere in a cubic.I follow the instruction from 2d band analysis. But it does not converge
Could anybody tell me how to mesh the 3D photonic crystal? my structure is a sphere in a cubic.I follow the instruction from 2d band analysis. But it does not converge
Hua Zhang
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Posted: 1 decade ago 24 avr. 2011, 08:21 UTC−4
I need somebody help me````
I need somebody help me````
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 24 avr. 2011, 12:52 UTC−4
Hi

I do not really know what to answer ;)
obviously you managed to mesh since you say it does not converge.

In RF the most tricky is the mesh size w.r.t. expected wavelength, have you checked that your mesh density resolves the highest wavelength in the densest material ? The main difficulty in RF is the large models, slow convergence and long cycle time for debugging

--
Good luck
Ivar
Hi I do not really know what to answer ;) obviously you managed to mesh since you say it does not converge. In RF the most tricky is the mesh size w.r.t. expected wavelength, have you checked that your mesh density resolves the highest wavelength in the densest material ? The main difficulty in RF is the large models, slow convergence and long cycle time for debugging -- Good luck Ivar
Andrei
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Posted: 1 decade ago 28 févr. 2012, 10:46 UTC−5
Hello Hua Zhang

Have you found a solution how to simulate the 3D photonic crystal band structure?

--
Best regards,
Hello Hua Zhang Have you found a solution how to simulate the 3D photonic crystal band structure? -- Best regards,
Fei Wang
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Posted: 9 years ago 23 oct. 2015, 15:11 UTC−4
I want to get photonic band gap of 3D PC
I want to get photonic band gap of 3D PC
Tianjing
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Posted: 8 years ago 25 avr. 2017, 11:18 UTC−4
Hi, Fei Wang,

Have you succefully gotten the photonic band gap of 3D PC?

Thanks
Tianjing
Hi, Fei Wang, Have you succefully gotten the photonic band gap of 3D PC? Thanks Tianjing

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