From raw data to processed spectra: A step-by-step guide

Optical spectroscopy is an important and widely used technique, for instance, to characterize new materials and to identify unknown compounds. Spectra are typically reported as a function of the wavelength of light, yet the information extracted from such spectra can be misleading. In contrast, spectra represented as a function of the frequency (or photon energy) allow for a more direct extraction of the intrinsic quantum-mechanical properties of the materials under investigation. Here, we discuss this conversion for absorption, fluorescence, and fluorescence excitation spectra. We show step-by-step the different factors that lead to a rescaling of the measured absorption and fluorescence signals.