Learning Forum

[Kyle]

This is a question regarding the example: https://support.lumerical.com/hc/en-us/articles/360042322634-Biosensor-circuit

I am trying to reproduce this example, and I had the following questions and was wondering if anyone could help with this:

1. Where is the source light physically located here? I see the wavelength used in the Eigensolver analysis box, but where is the physical location of the source?  
2.  How do I change the source to be purely TE/TM mode light?

[Kyle]

A mode solver calculates the modes of a waveguide, so it doesn't have a light source. In this example we take the mode properties calculated from the FDE solver and apply them to waveguide models in INTERCONNECT. The "light source" in the INTERCONNECT simulation is the ONA, which measures the transmission through the circuit.
As mentioned above, the FDE solver doesn't have a light source. It will find both TE and TM modes, as long as you haven't applied any symmetry boundary conditions. To change the mode input by the ONA in INTERCONNECT, you can change the "orthogonal identifier". Note that you set which orthogonal identifier corresponds to which mode when exporting the results from the FDE solver, as mentioned in this example. You will have to make sure the elements in the circuit have the right data for the modes you're selecting.