The resulting signal, an interferogram, is a complex pattern that, through Fourier Transformation, is converted into a spectrum representing molecular absorption as a function of wavelength or ...

While the Fourier transform gets all the attention ... You can think of the transform as a function that produces a 90 degree phase shift with a constant gain. For negative frequencies, the ...

A mathematical theorem stating that a PERIODIC function f(x) which is reasonably continuous may be expressed as the sum of a series of sine or cosine terms (called the Fourier series), each of which ...