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

Abstract

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. This paper will assist instructors who aim at developing an (under-)graduate lab to introduce into the methodology and terminology of spectroscopic experiments and to provide clear, step-by-step guidelines for data analysis and representation.