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Simulating chiral media

Posted 30.01.2015, 03:20 GMT-5 RF & Microwave Engineering, Materials, Modeling Tools & Definitions, Parameters, Variables, & Functions Version 5.1 3 Replies

Affar Karimullah
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Hi,
I am trying to simulate chiral media as explained in "alphard.ethz.ch/hafner/Workshop/Comsol2009.pdf". My understanding of adding the chiral expression for the electric displacement is that I add a wave equation to the EM physics and then select my domain (in the middle of the structure) and then change the equations for that domain. I found the electric displacement equation and changed it accordingly for all three E components, unlike what is shown in the presentation here (only one equation). First of all is this correct?
Secondly once I simulate it for linearly polarized light, what I find odd is that the E field before reaching the chiral domain has also been affected. What could I be doing wrong? I found the equation for the B field it was curl of E, and hence I assumed no change was required to it as it would be calculated in accordance to the changes made to D. Could this be the problem?
3 Replies Last Post 17.03.2016, 08:28 GMT-4
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Hello Affar Karimullah

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Haizi Yao
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Posted: 9 years ago 30.11.2015, 22:19 GMT-5
The weak form of the chiral domain should be required to modified. The modified weak form is only related to the variables E (Ex,Ey,Ez), so you can only directly obtain the electric field E. If you want to get other electromagnetic information such as H, B and D, you can get them by using the "new" constitutive relation for chiral media.
The weak form of the chiral domain should be required to modified. The modified weak form is only related to the variables E (Ex,Ey,Ez), so you can only directly obtain the electric field E. If you want to get other electromagnetic information such as H, B and D, you can get them by using the "new" constitutive relation for chiral media.
Seojoo Lee
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Posted: 9 years ago 07.02.2016, 04:48 GMT-5
Hi ,
I have had a hard time to simulate chiral media ..

I wonder that do i use the 'RF module' or just 'weak form PDE module' ?
I tried to modify the Helmholtz equation in RF module but i couldn't fine the way to modify it.
also i tried to use weak form PDE but i haven't succeeded yet ...

please help me.


Hi , I have had a hard time to simulate chiral media .. I wonder that do i use the 'RF module' or just 'weak form PDE module' ? I tried to modify the Helmholtz equation in RF module but i couldn't fine the way to modify it. also i tried to use weak form PDE but i haven't succeeded yet ... please help me.
Haizi Yao
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Posted: 9 years ago 17.03.2016, 08:28 GMT-4

Hi,
I am trying to simulate chiral media as explained in "alphard.ethz.ch/hafner/Workshop/Comsol2009.pdf". My understanding of adding the chiral expression for the electric displacement is that I add a wave equation to the EM physics and then select my domain (in the middle of the structure) and then change the equations for that domain. I found the electric displacement equation and changed it accordingly for all three E components, unlike what is shown in the presentation here (only one equation). First of all is this correct?
Secondly once I simulate it for linearly polarized light, what I find odd is that the E field before reaching the chiral domain has also been affected. What could I be doing wrong? I found the equation for the B field it was curl of E, and hence I assumed no change was required to it as it would be calculated in accordance to the changes made to D. Could this be the problem?


Dear Affar,

How about your progress about modeling the chiral media using the COMSOL software? I have succeed in replicating the Figure 7 in the paper of "alphard.ethz.ch/hafner/Workshop/Comsol2009.pdf", but i can't replicate the Figure 5. I don't know why, maybe my model is not completely correct? Besides, i found that the model geometry is not as what described by the author in the paper. when have a close view on the Fig.7 we can easily find that the modeled chiral sphere has a shell layer, however the author state in the section one that the chiral sphere is modeled as a uniform particle of a effective parameters. Though i also have done some tries in modeling it with a shell layers, i have't be successful in replicating the Fig.5.

Did your group get some substantial progress in the problem? it will be appreciated if you can share your valuable experience with me. And please don't hesitate contact me if you need my COMSOL model. My email address is : haiziyao@gmail.com.

Best wishes !

Haizi Yao
[QUOTE] Hi, I am trying to simulate chiral media as explained in "http://alphard.ethz.ch/hafner/Workshop/Comsol2009.pdf". My understanding of adding the chiral expression for the electric displacement is that I add a wave equation to the EM physics and then select my domain (in the middle of the structure) and then change the equations for that domain. I found the electric displacement equation and changed it accordingly for all three E components, unlike what is shown in the presentation here (only one equation). First of all is this correct? Secondly once I simulate it for linearly polarized light, what I find odd is that the E field before reaching the chiral domain has also been affected. What could I be doing wrong? I found the equation for the B field it was curl of E, and hence I assumed no change was required to it as it would be calculated in accordance to the changes made to D. Could this be the problem? [/QUOTE] Dear Affar, How about your progress about modeling the chiral media using the COMSOL software? I have succeed in replicating the Figure 7 in the paper of "alphard.ethz.ch/hafner/Workshop/Comsol2009.pdf", but i can't replicate the Figure 5. I don't know why, maybe my model is not completely correct? Besides, i found that the model geometry is not as what described by the author in the paper. when have a close view on the Fig.7 we can easily find that the modeled chiral sphere has a shell layer, however the author state in the section one that the chiral sphere is modeled as a uniform particle of a effective parameters. Though i also have done some tries in modeling it with a shell layers, i have't be successful in replicating the Fig.5. Did your group get some substantial progress in the problem? it will be appreciated if you can share your valuable experience with me. And please don't hesitate contact me if you need my COMSOL model. My email address is : haiziyao@gmail.com. Best wishes ! Haizi Yao

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