Learning Forum

[WENKAI YANG]

Recently I want to pursue the dynamic operation of a ring modulator. It means that I need to measure the BER and eyediagram, etc. So I did the experiment based on the example called Ring modulator time domain. The URL is below:

https://optics.ansys.com/hc/en-us/articles/360042329094-Ring-modulator-time-domain-INTERCONNECT-

 

The example uses straight waveguide instead of mode waveguide to simplify the simulation, but I still need to use mode waveguide to start the experiment. However, during the experiment I found that once I use the mode waveguide, the FSR of transmission spectrum under impulse response mode become smaller as shown in Figure below:

 

From the example, the exxperiment is feasible only when the transmission spectrum of scattering analysis and impulse response are same as shown below:

 

In this case, I wonder what is the problem.

Thank you and wish your reply.

[Guanhui Wang]

Hi WENKAI YANG,

I feel like this is related to the digital filter setting in the MODE Waveguide element. Please make sure you use the "group delay" option for the number of taps estimation. If this is not the problem, please send us the file for debugging. Thank you.