Spectrum using FFT

[cschneider]

Hi,

I am trying to convert a time-domain signal to frequency domain using FFT Spectrum (Mag-Phase).vi. As the time-domain signal is a laser pulse which is in the range of femtoseconds (10e-15s), i get frequencies in the THz range. My problem is now that the scale using FFT Spectrum starts at 0 Hz, I can't find a method to tune up the resolution of my spectrum...I only need a small range of frequencies in the THz range and not the whole range from zero on...

Somebody can help me how to convert my laserpulse to a spectrum? Using another vi?

Thanks in advance,

Christian 

[Coq_Rouge]

It is not a problem to pick out parts of a FFT and discard non interesting parts. Then performing a FFT analysis the result is placed in "bins" The width of bins and how many will depend on sample rate and how many samples. I do not know what you know about FFT. But I give you some links. They are good reading. You can post again after reading them.

http://zone.ni.com/devzone/cda/tut/p/id/4541

http://zone.ni.com/devzone/cda/tut/p/id/4278