How to remove sum and frequency components in FFT spectrum during signal resampling.? I am working on to remove non linear tuning of laser . I am using resampling technique based on triggering technique .
Firstly, I make collect a vector of maxima and minima from Tigger sine wave of frequency F1. Then I reconstruct signal sine wave (of frequency F2) with the maxima and minima vector from the trigger. FFT is performed after this step to identify noise free frequency components of the signal.
This kind of of resampling is working excellent. But after FFT,  besides the actual frequency component of the signal wave, it also gives rise other unwanted frequency components.
These are exactly sum and frequency components arising from F1 and F1,( i.e., F1+F2 &amp; F1-F2 ).
For the clear understanding of my question please refer to attached image  and suggest me the possible solution to avoid these unwanted frequency generations.
thank you
You should be using an appropriate low pass filter during reconstruction.