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CONNECTION between 3-D eigenfrequency analysis & 2-D mode analysis

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I use 3-D Eigenfrequency Analysis vs 2-D Mode Analysis to solve the eigenmodes in conventional ridge waveguides. Even though I have successfully got the expected results, there are still some problems or concepts needed to be clarified, and I seperate them into two main parts:
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Firstly,

Please check the attached PNG file:

I respectively get “Eigenfrequency” in 3-D Eigenfrequency Analysis and “Effective Index” in 2-D Mode Analysis, BUT:

1. What’s the connection between this two calcuation modes, 3-D Eigenfrequency Analysis and 2-D Mode Analysis?

2. How to get the “Effective Index” from 3-D Eigenfrequency Analysis, and “Eigenfrequency” from 2-D Mode Analysis?

I believe these two distinct tools must be able to be linked together!!

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Secondly,

I found there is a package tool contained in the RF Module, called "Eigenvalue mode", which are also shown in my attached file.

I wanna set this tool to be "3-D" mode analysis, but I'm curious about the definition of eigenvalue in the EM wave cases. To my knowledge, the eigenvalues in the EM wave cases described by Maxwell equations should be k0, which is a wavenumber of light propagating in the structure. But as I designate one initial eigenvalue for the solver, it can't derive the same electric field distribution as that in the 3-D Eigenfrequency analysis.

So, here, I just need some "instruction" for how to use the Eigenvalue Mode to achieve the same results as 2-D Mode Analysis and 3-D Eigenfrequency Analysis.
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Your kind reply would be highly appreciated. Thank you for your patience,


1 Reply Last Post 10.10.2012, 01:29 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 10.10.2012, 01:29 GMT-4
Hi

have you checked the doc, the help file i.e "Step-Index Fiber" and the model library xamples, htere are further explanations there. Try a search on "effective refractive index"

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Good luck
Ivar
Hi have you checked the doc, the help file i.e "Step-Index Fiber" and the model library xamples, htere are further explanations there. Try a search on "effective refractive index" -- Good luck Ivar

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