Learning Forum

[YOON Seokhyeon]

Hello, everyone

I'm trying to do simulations on the transmission with respect to the length variations of the SiN taper. 

The structure is as shown in the picture below. 

I used a SiN core and SiO2 cladding.  [parameters -  W_max: 1.6 μm / W_min : 0.3 μm / Length_taper : 100 μm / Height : 0.22 μm / length variations : 100 - 800μm]

I connected 10μm strip waveguides to both ends of the taper, and the source starts from strip with W_max.

From the beginning of the source, the first monitor is the beginning of the taper, and the second one is the end of the taper. I checked the transmission at the end.

 

I expected an increase in transmission as the length increases, but the results show a contrary decrease. 

I want anyone to let me know if there's anything I'm missing. 

Thank you.

[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

[YOON Seokhyeon]

Hello Dimitris,

First of all, I'm sorry for the late reply and thank you for your reply.

I think my simulation is wrong, too.  I'll proceed with the method told you above. 

 

Kind regards

Yoon.