Comparing the real and imaginary parts of a photoacoustic infrared spectrum

Abstract

Vibrations among atoms in a solid material can be triggered by absorbing infrared light. The energy associated with different kinds of vibrations, such as bending or stretching, are in uenced by the types of atoms and their arrangements. Photoacoustic Spectroscopy (PAS) is an experimental technique that allows us to assess what energies of infrared light a solid material can absorb. In this thesis, we focus on implementing mathematical tools and methods on previously collected photoacoustic spectra to manipulate the data in a new way. The goal is to extract the real and imaginary parts of various photoacoustic infrared spectra. Once extracted, we analyze the data to determine whether there are consistent differences (or similarities) between the two parts as we keep the sample the same, but change the photoacoustic detection parameters. We then evaluate which additional terms have to be considered to account for these differences or similarities, and analyze whether they are solely due to instrumentation effects, or if they can provide us with useful information about the structure of our solid sample.