Discussion Forum

Dear comsolvers,

I define an external matlab function 'laguerre' in comsol to define a Laguerre Gaussian electric field profile. Note that the Laguerre function is in cylindrical coordinates. Eventually, I use this field to define my source as background electric field (Ebx, Eby, Ebz), guess this is cartesian.

My simulation took 4 minutes to run a Gaussian (in cartesian coordinates and without any call to external matlab function), while it took 3.25 h for an LG beam (cylindrical coordinates). In fact, on the 2nd run (with some settings change), it took 6.5 h!

To add further to the frustration, I had to wait for hours after I click on plot. I only try to plot the background field ewfd.Ebx. At this point, I just kill the application.

1) The live link connection to matlab was established and the matlab search path was set to point the location where the matlab function resides. But, I want to know if calling an external function could be the culprit. 2) Transformation from cylindrical coordinate system to carteisian for the solver is time consuming? and the application is trying to do the transformation after I click on plot?

If you have faced similar problems, please drop in a word. Or Can you speculate what you think the problem is or offer any advice that can possibly help me to resolve the issue. Many thanks in advance.