Scattering loss measurements of evaporated slab waveguides of SiO2 and NdF3 using a prism coupler and angle-limited integrated scattering

A method for finding the attenuation coefficient of a planar or channel wav eguide is described. Results for SiO2 and NdF3 waveguides were obtained, sh owing that the latter presents better attenuation characteristics. The infl uence of the prism shape on the measurements was also tested and found to r esult in variations in the measured attenuation coefficient. Two different locations of the waveguides were selected for the coupling, and again varia tions occurred. suggesting irregular thickness of the thin films. The metho d uses concepts based on the angle-limited integrated scattering technique and also on the well-known prism coupling method. It may be possible to mak e the system fully automatic. (C) 2000 Society of Photo-Optical Instrumenta tion Engineers. [S0091-3286(00)03102-0].