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The field of graphene-based plasmonic waveguide

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Hi, everyone.
I have recently simulated graphene-based plasmonic waveguide at 10 THz. The thickness of graphene is set to be 0.7nm. I use relative permittivity to represents the graphene. Now, when the single graphene is neglected or considered in my modal, the Effective mode index does not change, the fied distribution does not change, only the change of the electric field amplitude. I wonder the thickness of graphene is too thin to influence optical field. Whatever graphene is considered or not considered, the field is only suuported by dielectric waveguide mode.

So, How can I do that graphene can affect the optical field of the waveguide.
Or any other suggestions to solve this problem.

best regards,
Pengchi

3 Replies Last Post Dec 16, 2015, 8:51 p.m. EST

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Posted: 9 years ago Nov 26, 2015, 4:18 a.m. EST

Hi, everyone.
I have recently simulated graphene-based plasmonic waveguide at 10 THz. The thickness of graphene is set to be 0.7nm. I use relative permittivity to represents the graphene. Now, when the single graphene is neglected or considered in my modal, the Effective mode index does not change, the fied distribution does not change, only the change of the electric field amplitude. I wonder the thickness of graphene is too thin to influence optical field. Whatever graphene is considered or not considered, the field is only suuported by dielectric waveguide mode.

So, How can I do that graphene can affect the optical field of the waveguide.
Or any other suggestions to solve this problem.

best regards,
Pengchi


[QUOTE] Hi, everyone. I have recently simulated graphene-based plasmonic waveguide at 10 THz. The thickness of graphene is set to be 0.7nm. I use relative permittivity to represents the graphene. Now, when the single graphene is neglected or considered in my modal, the Effective mode index does not change, the fied distribution does not change, only the change of the electric field amplitude. I wonder the thickness of graphene is too thin to influence optical field. Whatever graphene is considered or not considered, the field is only suuported by dielectric waveguide mode. So, How can I do that graphene can affect the optical field of the waveguide. Or any other suggestions to solve this problem. best regards, Pengchi [/QUOTE]


Maxim Electromobility

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Posted: 9 years ago Dec 10, 2015, 1:46 p.m. EST
Hi Pengchi,

The field does not interact with graphene if the electric field is normal to the graphene sheet. You need to have a strong in-plane component of electric field to have the interaction.

And it is better to model graphene as a 2D current density in the boundary conditions.

Best regards,
Maxim
Hi Pengchi, The field does not interact with graphene if the electric field is normal to the graphene sheet. You need to have a strong in-plane component of electric field to have the interaction. And it is better to model graphene as a 2D current density in the boundary conditions. Best regards, Maxim

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Posted: 9 years ago Dec 16, 2015, 8:51 p.m. EST
Hi Maxim,

Thank you so much for your reply. I have already modeled graphene as a surface current density. Indeed, the electric field does not interact with graphene when the incident elecric filed is normal to the graphene.The reason is the fact between TM mode and TE mode.

Thanks a lot for your help again.

Pengchi
Hi Maxim, Thank you so much for your reply. I have already modeled graphene as a surface current density. Indeed, the electric field does not interact with graphene when the incident elecric filed is normal to the graphene.The reason is the fact between TM mode and TE mode. Thanks a lot for your help again. Pengchi

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