What is “f” in 1/f noise?

Hi,

Could anybody please help me to figure out the concept behind "flicker noise"? I know that it shows a 1/f dependence as a function of frequency (f) but I DO NOT KNOW what this frequency is? Frequency of what?

Such a noise is a dominant one in diode lasers and in order to understand these kind of lasers, I do need to know the noise. For example, one of the limiting points in absorption spectroscopy using diode lasers is 1/f noise but as I said, I really do not know what this f means?

I looked on web to find some sources and get my answer but none of those answered my question.

Any help will be highly highly appreciated,

Thanks,

Sor

1/f refers to the frequency distribution of the noise. At a given frequency (f) the noise is 1/f, so there is a lot more noise amplitude at low frequencies than at high frequencies (also called pink noise).

White noise is evenly distributed over frequency, so it is "1" noise (no frequency dependent component to the amplitude (power) function).