Learning Forum

[Nishith Narendra]

Hi everyone,

I am simulating ring resonators in the Interconnect platform by breaking it down into the basic components (directional coupler, curved waveguide, straight waveguide). I have added an S-parameter block (S-par 1) in the Interconnect (figure 1)..

This block corresponds to an FDTD simulation of a straight waveguide with a nanorod on top of it. The 3D fdtd simulation of the waveguide and gold nanorod is done as shown in fig. 2. The boundaries are PML, and there is a finner mesh around the nanorod with step size 2x2x2 nm^3.

Wavelength range: 1480-1530 nm,

mesh accuracy : 2 

At the drop port output of the ring resonator (input 2 in the ONA), I get a normalized power transmission exceeding 1 (figure 3), which is a violation of energy conservation. Could anyone help me with this issue ?

Thank you.

[Nishith Narendra]

Please, do let me know if more information is required.

[Kyle]

Hello Nishith, sorry for the delay in getting back to you. Have you verified that the S parameters are passive? You can make sure that the S-parameters are passive by changing the "passivity" property of the S-parameter element to "enforce":

[Nishith Narendra]

Hi,

This issue was solved. The problem was with the FDTD simulation of the nanorod with the curved waveguide. There were reflections from the PML boundaries that were increasing on combining with the ring.