Learning Forum

[megan.obrien]

Hi,

I want to try and simulate an add drop racetrack resonator in Interconnect. The schematic of the circuit I have at the moment is the one in this example:https://optics.ansys.com/hc/en-us/articles/360042323794-Ring-resonator-using-INTERCONNECT-primitive-elements , but with no hangover waveguides included. I see for the waveguide coupler components in Interconnect that you can only input either the coupling coefficient or length and not both. Right now the only lengths I have included is for the bent sections (i.e. two Straight Waveguide components with each part = pi*bend radius). If I want to include the straight sections of the ring correctly then should I define the length of the straight waveguide component to be pi*R + coupling length? Thanks

 

[Kyle]

Hi, yes, the coupler elements in INTERCONNECT are "point couplers", so they don't include the change in phase from propagation through the coupling region. This change in phase can be included in the straight waveguide components by including the length of the coupling region in the waveguide sections, as you mentioned.

Alternatively, you can calculate the S-parameters of the coupling region in a physical solver like FDTD and import this data into an S-parameter element in INTERCONNECT. In this case, the S-parameters include the phase shift data, so the length of waveguide included in the S-parameter data (in other words, the waveguide between the ports in FDTD) should not be included in the waveguide elements.

[megan.obrien]

Hi Kyle,

Many thanks for your help. If I were to calculate the S-parameters of the coupling region and import them into the Interconnect simulation, would this example be a good one to follow?: https://optics.ansys.com/hc/en-us/articles/360042322794-Ring-Modulator

[Kyle]

Hi, that example uses the same point coupler approach used in the first example you linked. I don't think we have an example of importing the coupler S-parameters into INTERCONNECT for the ring coupler. Typically it is easier to use the simpler point coupler approach, especially if you want to do time domain simulations in INTERCONNECT.

You can look at this example for how to import S-parameters from FDTD into INTERCONNECT: Y branch – Ansys Optics (https://optics.ansys.com/hc/en-us/articles/360042800353).

You can also use the FDTD simulation of the coupling region in the ring modulator example as a basis of your FDTD simulation.