Absorption and scattering in low-loss polymer optical waveguides

The absolute absorption spectra of low-loss optical waveguides, together wi th their intrinsic and extrinsic scatterings, were measured in the near inf rared. Photothermal deflection spectroscopy was used to measure the full ab sorption spectra of a series of fluorinated cross-linked polymers. Assignme nt of-CH3,-CH2-, and -OH overtones as well as of combinations of overtones were made by use of the theory of anharmonic vibrations based on a Morse po tential for local modes. Details of the molecular potential are given. The total attenuation in slab waveguides made with these polymers was measured by a prism-coupling technique and compared with the absolute absorption. Lo sses that are due to the material itself and those that are due to the proc essing are quantified. (C) 2001 Optical Society of America.