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Circular polarization and Port
Posted Sep 25, 2012, 10:05 a.m. EDT RF & Microwave Engineering Version 4.3 2 Replies
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I am simulating an optical fibre and more particularly a fibre tip. For this it is preferable to use circular polarization. Circular polarization can be defined e.g. with a scattering boundary condition, setting the Ex and Ey components to have a phase difference of exp(i*pi/2), with z the propagation direction. This gives a flat field amplitude over the fibre cross-section. However, I would like to have the proper amplitude-distribution over the fibre. I could implement functions for the amplitude-distribution, e.g. Gaussian. But it would be nice to use Port and find the mode using Comsol.
Is there a way to use Port & Type = Numeric to get circular polarization?
Circular polarization is just a superposition of two linear polarizations, so it should in principle be possible to solve for TE and then TM, and superimpose the two resulting field-distributions. Maybe there is a way to do two Boundary Mode Analysis, find the TE and the TM-solution, and use the phase-shifted sum of the two as the input field?
Is there a way to use Port & Type = Numeric to get circular polarization?
Circular polarization is just a superposition of two linear polarizations, so it should in principle be possible to solve for TE and then TM, and superimpose the two resulting field-distributions. Maybe there is a way to do two Boundary Mode Analysis, find the TE and the TM-solution, and use the phase-shifted sum of the two as the input field?
2 Replies Last Post Sep 25, 2012, 11:34 a.m. EDT
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Posted:
1 decade ago
Select "User Defined" and put your equation for incoming field. There is no way to do it under "Numeric". Is there a reason to keep it?|
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Posted:
1 decade ago
To put in an equation as "user defined" is the same as using Scattering Boundary Condition to put in the equation, right? But thanks, it sounds more correct than using Scattering Boundary for an input field.
The point of using Numeric is that my fibre has a gold-coating on the outside of the core and later on we might use a non-circular fibre. So I would prefer to find the mode using Comsol rather than putting in an analytical expression.
The point of using Numeric is that my fibre has a gold-coating on the outside of the core and later on we might use a non-circular fibre. So I would prefer to find the mode using Comsol rather than putting in an analytical expression.