Reply To: Transmission issue of SiN taper at 1550nm

[Dimitris Polyzos]

Hello Yoon, 

thank you for contacting us. I would suggest to have a look at the following articles:

Tapered-waveguide

Linear-waveguide-taper

Polarization-converter-using-a-tapered-waveguide

You can check these examples how they implement a tapered waveguide, as indeed increasing the length the transmission should increase as it is depicted in this picture (of the shared example).

Also, at the top of my head, you should conduct a convergence test for a number of modes and fot the meshing of your simulation model. That might be the reason of getting smaller tranmission for longer length. Could you please let me know how much is the transmission difference for input output?

Convergence+test-FDTD

Convergence-testing-process-for-EME-simulations

EME-Convergence-Testing-An-Intuitive-Approach

I hope I helped. Please let me know if you need further assistance. 

Kind regards

Dimitris