# Perform a Fourier Transform on a wavelength scan

I have a plot of the power transmitted through a device as a function of wavelength, from 1500 to 1600nm. There is some Fabry-Perot noise, plus I suspect some other regularities. I would like to perform a Fourier analysis of the data, with the final goal of getting a frequency or, better, the cavity length at the origin of any periodicity.

I tried with Fourier, but I would like to correct for the fact that my scan doesn't start from 0, and I couldn't find anywhere the answer to that question. Moreover, I know that the Fourier transform will live in k-space, but I am having some problems in moving to a frequency space. Can anybody give me some hints?

• Can you post the data you are working with ? – Sektor Aug 6 '15 at 10:01
• I put together some information on Fourier [here] (mathematica.stackexchange.com/questions/85139/…) this may help. In particular Fourier does not require the x values of your data only the y values. – Hugh Aug 6 '15 at 10:17