Wave Optics in Infrared Spectroscopy starts where conventional books about infrared spectroscopy end. Whereas the latter are based on the Bouguer-Beer-Lambert law, the cornerstones of this book are wave optics and dispersion theory. This gap between both levels of theory is bridged to allow a seamless transition from one to the other. Based on these foundations, the reader is enabled to choose which level of theory is adequate for a particular problem at hand. Advanced topics like 2D correlation analysis, chemometrics and strong coupling are introduced and viewed from a wave optics perspective. Spectral mixing rules are also considered to better understand spectra of heterogeneous samples. Finally, optical anisotropy is examined to allow a better understanding of spectral features due to orientation and orientational averaging. This discussion is based on a 4x4 matrix formalism, which is used not only to simulate and analyze complex materials, but also to understand vibrational circular dichroism from a (semi-) classical point of view. Wave Optics in Infrared Spectroscopy is written as a tool to reunite the fragmented field of infrared spectroscopy. It will appeal to chemists, physicists, and chemical/optical engineers.