Learning Forum

[bernhard1]

Hello everyone,

I am designing grating couplers. For this purpose I want to split the simulation into a short/small FDTD simulation containing the grating and a larger simulation using EME where I want to refocus the light using a long taper.

I managed to export the fields from the FDTD simulation with a frequency and power monitor and I also managed to import them to a port of the EME simulation. But when I do the EME simulation there is no light detected at the other port. I am using 100 modes for the cell groups.

Do you think I have to increase the number of modes or is importing fields from FDTD to EME not supported? Or do you know what the problem could be here?

[Guilin Sun]

I am not sure how did you import for the data. But you will need to create a dataset with E/H and xyz. Please refer this exmaple:
https://support.lumerical.com/hc/en-us/articles/360034396394-Importing-arbitrary-source-fields-into-EME-ports

[bernhard1]

I didn't work beforehand but I found out that i can remove the frequency dimension with the "pinch" command and by that it works!

[Guilin Sun]

You are right that for EME source it does not need the frequency parameter since it is single frequency job.

[bernhard1]

Yes, I think that this should be stated somewhere on the support pages that you have to modify the data set accordingly for importing a source from FDTD to EME in comparison to FDTD->FDTD. Maybe you could forward this to someone who is maintaining these sites.
Thanks!

[Guilin Sun]

Ok, Thank you for your suggestion!