Control unit

Hi Folks,

I am using a ring modulator as a filter and I want to automatically control (change) the drive voltage of the modulator according to an input data symbol. I wonder if there is any control unit in INTERCONNECT which allows me to do this function???

Thanks, In advance.

Hi @basma.eldosouky,

Do you want a feedback loop kind of signal stabilization control, or just a symbol mapper from digital signals to electrical signals? For the later one, you can use the Modulation Symbol Mapper element to control the electrical signal output based on digital signals.

For a feedback loop control, I believe we can do it in INTERCONNECT, but please let me know some more details about its behaviour to better help you with the most propriate design.

Hi @gwang,

Thanks a lot for your reply. I just need an element to control the electrical signal output based on digital signals, so the modulation mapper is more sufficient for my purpose.

Hi @basma.eldosouky,

Glad this helped. Please mark the post as resolved if your inquiry is addressed and open up new posts if you have further problems :slight_smile:

Hi @gwang,
Could you please elaborate on how to control feedback loop in Interconnects. Also I want to know whether one can control the connection (optical/Electrical) length from element to another element in the Interconnects.

Hello @wani,

This would depend on the details of the feedback loop. Can you please provide more details on what you would like to do?

The connections in Interconnect don’t really have a “length”, the signal is passed directly from one element to another along the connections. For optical connections, you can use fiber or waveguide elements, which can have their lengths specified.

Hi @kjohnson

Thanks for your reply.

I want to simulate the design as shown in the Fig 2 of the following paper:
Wideband tunable microwave signal generation in a silicon-based optoelectronic oscillator.
In the design the control on feedback loop length is important for achieving the tuning of the frequencies. So, I want to have control over loop length to target different frequencies. Moreover, I have attached my interconnect file of this design here.

Also, I wanted to know if it is possible to do the simulation of this design on other Lumerical softwares like Lumerical Device (having optical structures along with electrical part). If, how to simulate this design?



MZM_RING_OEO.icp (659 KB)

Hello @wani,

If the delay of the feedback is important, instead of changing the length it might be easier to use a delay element:

You can simulate the individual devices using the physics solvers, however I think the circuit itself is best simulated using INTERCONNECT. You can see some example simulations of the devices in this circuit using the other solvers in the Application Gallery, for example:

Please let me know if you have any other questions.

Thanks for the reply,

I have few queries:

  1. How to calculate phase noise for the Rf generated signal?SingleMZM-OEO.icp (936.1 KB)
  2. The oscillations produced at are square wave, however I want to achieve sinusoidal waveform. So how to achieve sinusoidal oscillations?

Any guidance, tutorial in this regard will be highly appreciated.

Hello @wani,

You can calculate the total noise using the Optical Channel Analyzer element, but to calculate the phase noise I believe you will have to use the spectrum analyzer element, either the optical or the electrical version.

I increased the sample rate and the square oscillations disappeared. Accurate results should not change with an increase in the sample rate, so I don’t think the square wave results you are seeing are reliable. If you would like to replicate the results in the paper, I think you will have to change the properties of the ring resonator, MZM and waveguide elements from their defaults to match their values in the paper. Some tuning of the gain elements will likely be required as well. It might also be helpful to try setting up this circuit using simpler elements, like the Fabry-Perot filter instead of the ring resonator, to make sure the simulation works as expected before using more complex elements

Let me know if you have any questions.