propagation loss constant in the microring resonator (α)

afshiinafshiin Member Posts: 3
edited April 28 in Photonics


I wanted to know how the propagation loss constant (α) can be calculated for the microring resonator?

I know that a(rt) = exp (-α *π* R), which a(rt) is the round-trip field attenuation factor in the microring.

Now I want to know how to calculate the alpha value in Lumerical software.

Please help.😊


  • kjohnsonkjohnson Posts: 91Ansys Employee

    Hello @afshiin ,

    The propagation losses in a bent waveguide can be calculated with the FDE solver in MODE, which is demonstrated in this example:

    Depending on how you're defining the round trip losses, the coupling losses in the coupling regions of the ring resonator might also be included. The power coupling coefficients can be calculated with FDTD, as in step 1 of the ring modulator example:

    A similar approach for calculating coupling coefficients is used in step 4 of this example:

    These are the sources of loss in the ring, so you can use these to calculate the round trip attenuation factor, which will give you the propagation loss constant with the formula you provided. Note that losses from scattering due to surface roughness are not included in the FDE solver results, and are difficult to obtain in simulation in general. It might be a good idea to add some extra loss to the propagation loss from the simulation to account for this, for example, based on previous experimental results.

    Please let me know if you have any questions.

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