The spectral properties of single-mode optical fibers and optical waveguides are reviewed including loss, dispersion, coupling, and reflection. Measurement techniques for characterizing these waveguides are described and experimental results are presented. These include measurements of the intrinsic and bending losses for single-mode optical fiber, field mode size, transmission, and reflection losses for waveguide structures when single-mode fibers are used to couple power into the waveguides.
G. J. Herskowitz,
"Spectral Characterization Of Optical Waveguides", Proc. SPIE 0835, Integrated Optical Circuit Engineering V, (10 March 1988); doi: 10.1117/12.942362; https://doi.org/10.1117/12.942362