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Ansys Learning Forum › Forums › Discuss Simulation › Photonics › Coupling length measurement › Reply To: Coupling length measurement

May 3, 2024 at 5:45 pm
Guilin Sun
Ansys Employee

This is doable via FDTD, and possibly with FDE's help to get the proper sweep range.

I would suggest that you first create the two waveguides (ring and the straight ) in FDE, and set proper bending radius accordingly. Then you can estimate the coupling length when you simulate the modes for the two waveguides separately, where delta_n is the difference of the neff for the two modes. You can also estimate the couling efficiency after you copy one of the modes to the global deck with overlap. 

In FDTD, you can simulate part of the ring with the straight "bent" waveguide with titled ports inside the ring, and sweep the gap/arc length.

As for the coupling length measurement, you may define the arc length of the straight wavefuide. It is up to use for the definition.

 

 

 

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