Optical preprocessing in spectroscopy

This technical report reviews the state of the art in optical preprocessing for spectroscopic applications. In particular, unconventional spectral techniques are reviewed that do not use a spectrometer, or make no use of it in the classical manner. In a theoretical part of this technical report, a vector space representation is derived to describe spectral processing and necessary assumptions are outlined. Based on this mathematical concept, optimal optical filters for spectroscopic applications can be designed. The second part of the technical report is about the optical hardware of these unconventional spectral technics