# can the optical loss from fiber to waveguide be calculated by lumerical?

#1

Hello everyone
Now I want to do a simulation about the optical loss from the optical fiber to waveguide?Do the lumerical have any example about the calculation? Can anyone give me an example about the issue.Thanks a lot!!

#2

Hi @jbwei
In integrated optics there are two possible ways for coupling light between SOI waveguides and optical fibers. The one is “grating couplers” and the other is “fiber-chip edge couplers”. In Lumerical’s knowledge base there are examples for these subjects.
Informations and examples about “grating couplers” can be found here: https://kb.lumerical.com/en/index.html?pic_passive_grating_couplers.html
and about “fiber-chip edge couplers” here
https://kb.lumerical.com/en/index.html?pic_passive_edge_couplers.html
Is there another way for coulpling light between SOI waveguides and optical fibers ?

#3

dear konslekk
Thanks for your feedback.I will learn the two examples.Thanks for your help.

#4

dear konslekk
recently I have learnt the two example about the optical loss from fiber to waveguide.But I still don’t know which parameter can express the optical loss from fiber to waveguide.Can you help me and show me which parameter can express the optical loss from fiber to waveguide.You can just take theEdge_coupler1.lms (394.4 KB)
edge coupler as an example.Thanks a lot.

#5

Hi @jbwei

If you are interested to calculate the transmission from fibre to waveguide, you can calculate the s parameter as is shown in the edge coupler example and Abs(S21)^2 will give you the tranmission into the fundamental mode of waveguide. If you want to calculate the loss in your system or if you want to study the coupling to other modes, please see this link. In summary, your loss is total input field - total output field which can be calculate using the S matrix.