Editing Absorption spectroscopy (section)

===Relation to scattering and reflection spectra===
The scattering and reflection spectra of a material are influenced by both its [[refractive index]] and its absorption spectrum. In an optical context, the absorption spectrum is typically quantified by the [[refractive index#Dispersion and absorption|extinction coefficient]], and the extinction and index coefficients are quantitatively related through the [[Kramers–Kronig relations]]. Therefore, the absorption spectrum can be derived from a scattering or reflection spectrum. This typically requires simplifying assumptions or models, and so the derived absorption spectrum is an approximation.