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3D Boundary mode analysis for plasmonic waveguide

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Greetings.

I have a plasmonic waveguide - a silver brick on silicon substrate with glass cladding. I would like to know the modes which this waveguide supports. First I have made a 2D mode analysis and received an effective index for 6 modes around the supposed value (1.55 because surface plasmon should propagate along the silver-glass interface) and electric field distribution. Next I decided to do similar simulation in 3D mode. I have created the wavefuide with silicon and glass slabs around it. The PML layers around the slabs are also used to reduce reflections.

I have added two ports, numerical type. I have also created two boundary mode analyses, one for each port. After the simulation was completed I received 6 effective indexes. The problem is that the electric field distribution is just a mess. Moreover it is independent from effective index selection.

I tried to change the port (the cross section of silver waveguide with silicon and glass slabs, just glass slab, just silver waveguide, just one port with PML termination on the opposite end) but received no effect.

What could be the problem? How can I receive the proper electric field distribution map of supported modes?

Thank you.


1 Reply Last Post 29.07.2013, 21:34 GMT-4

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Posted: 1 decade ago 29.07.2013, 21:34 GMT-4
I have overcome this. The problem was in standard plots of electric field - they are zero or near-zero values. To plot the electric field distribution of particular mode at particular port the expression "emw.normEbm_1" (2,3,4 depending of port number) should be used. This works only with surface plots, slices are not eligible. For more information look at polarized_circular_ports tutorial in COMSOL.
I have overcome this. The problem was in standard plots of electric field - they are zero or near-zero values. To plot the electric field distribution of particular mode at particular port the expression "emw.normEbm_1" (2,3,4 depending of port number) should be used. This works only with surface plots, slices are not eligible. For more information look at polarized_circular_ports tutorial in COMSOL.

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