Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Selecting boundary mode effective index.

Please login with a confirmed email address before reporting spam

I'm doing a simple dielectric waveguide problem with the EMW physics. It's a short piece of straight guide surrounded by cladding and PML. Ports at the ends. I have two numeric ports. Wave excitation on only for port 1. I have two BMA studies with the FD study. I choose to solve for 4 modes. I run the studies. Everything's fine except the solution is shown only for the 4th mode (if I choose 3 modes I see the result for only the 3rd mode, etc...). I can't find anything to select which mode to display. I expected a selection list box in, maybe, the 3D plot group node, or the surface plot node, or maybe even the data set node. No dice. Does anybody know where they hide the selector for the mode to show when solving for multiple modes? Or is this not controllable?

1 Reply Last Post 10.10.2016, 11:57 GMT-4

Please login with a confirmed email address before reporting spam

Posted: 8 years ago 10.10.2016, 11:57 GMT-4
I have adjusted the settings for "Search for modes around" and "Mode search method" so that the mode of interest ends up being the last (or only) mode.

A couple of tips:

- "out of plane wavenumber" may be a better way to choose/ identify modes

- if you have degenerate modes you may need to introduce a small asymmetry to split them.

DW Greve
I have adjusted the settings for "Search for modes around" and "Mode search method" so that the mode of interest ends up being the last (or only) mode. A couple of tips: - "out of plane wavenumber" may be a better way to choose/ identify modes - if you have degenerate modes you may need to introduce a small asymmetry to split them. DW Greve

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.