What is Spectrometer Noise?

Noise is a collective term for sources of unwanted signal. Some noise sources introduce systematic error, and can be corrected for, such as with a dark spectrum. Other noise sources introduce random error, and can be averaged out over several acquisitions. The different types of noise can be wavelength dependent or not. They can be due to the electronics and not dependent on the signal at all. The relevant types of noise in spectroscopy are: dark current, shot noise, readout noise, stray light, electronic noise.