Thanks Damian for your response.
I modified the code to be readable for you.
You’ll conclude from the code how to run it.
Run the time domain first then frequncy domain after removing % % from frequency domain part and adding % to time domain part.
Compare Optisystem_signal with Matlab_signal.
Although the power results is very close but the samples are not the same.
I Hope you tell me how the optisystem make fft.
Regards,