Overtone absorption in macromolecules for polymer optical fibers

The development of polymer optical fibers (POF) leads to the fundamental question about the lowest loss attainable with organic polymers. In the present paper, we address this question with experimental and theoretical work on vibrational overtone absorption of different molecular bonds, which is the dominant loss contribution in POF's. The investigations, the first of their kind for several bonds, show good agreement between experiment and theory for the experimentally accessible CH‐, CD‐, and OH‐vibrations. Applied to CF‐, CCl‐, and (CO)‐ vibrations, the calculations lead to the conclusion that in the most important wavelength region 600 – 900 nm fully halogenated polymers show a negligible loss contribution due to overtone absorption. In these cases, the theoretical lower loss limit should be a few dB/km.