AMPLITUDE MODULATOR NOT GIVING A CORRESPONDING AMPLITUDE MODULATED SIGNAL

[Taiwo Ambali Abiola]

I observed that using both Amplitude modulator and frequency modulator modules to modulate signals do not give corresponding amplitude modulated and frequency modulated signal out respectively. The same with Phase modulator when checked the output signal with Time Domain Visualizer. With Amplitude modulator, I am actually expecting and amplitude modulated signal in form of envelop. What is the hidden secrete behind this?

Thanks

[Damian Marek]

Could you please elaborate a little more? What type of output are you expecting and how it is different than the OptiSystem simulation?
Attaching your project file would also help.

[Taiwo Ambali Abiola]

Thanks Damian,
I am actually expecting and envelop modulated signal based on the theory of amplitude modulation as attached in the .JPG file attached. The attached Pdf is what I saw when the signal is amplitude modulated. I noticed frequency modulator and phase modulator modules are also not giving me the expected response base on theory.

Kindly help on what I am suppose to do.

Thanks.

[Alessandro Festa]

Hi Taiwo,

unfortunately, no attachment can be seen to your post. Can you post again and attach the images you are mentioning above?

[Taiwo Ambali Abiola]

Oh! sorry, Kindly find the two attached files. The last waveform (envelope) on the image file is what I was expecting but I got the attached pdf.

Kindly help.

Thanks

[Taiwo Ambali Abiola]

Seems I can not attach the files or two different formats. I did on two different system.

Attachments:

1. 

   Amplitude-Modulation.jpg
   

[Taiwo Ambali Abiola]

ok, here is what I got

Attachments:

1. Amplitude.pdf

[Ravil]

Hi Taiwo, according to the picture, which you have uploaded, you have your modulating signal. However, you are expecting to capture the envelope? I am not sure if OptiSystem allows you to do it this way. But, for the case of real oscilloscope I would agree with Alessandro…

[Alessandro Festa]

Yes, I do not see any option that allows you to detect the optical frequency instead of just the modulating signal at lower frequency…I don’t think you can do that with this visualizer on OptiSystem.

[Alessandro Festa]

I do not understand where the problem is…the visulaizer is showing what you would see on an oscilloscope, where you cannot measure the “optical frequency” oscillation at about 190THz!

[Ravil]

Yes, Alessandro. I completely understand your point and agree with your statement!

[Taiwo Ambali Abiola]

Oh! I see, thanks alot for the information both Festa and Ravil. I thought I would be able to see the envelope signals

[Ravil]

You are welcome, Taiwo! As a forum member, I am always glad to give you my advice when I can. Good luck with your work and research!

[Damian Marek]

Just coming back to give an official response, OptiSystem treats optical signals as complex envelopes for simulation purposes. It would slow down simulation time considerably if the software had to sample at optical frequencies >190 THz.

Regards

[Alessandro Festa]

You are welcome Taiwo!

[Taiwo Ambali Abiola]

Thanks a lot

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