Rayleigh backscattering measurement of 10 m long silica-based waveguides

The authors report the Rayleigh backscattering distributions of 10 m long silica-based waveguides fabricated on one substrate. These were obtained by using a range-extended optical low coherence reflectometer. The results reveal that the best sample waveguide has a uniform loss of 1.7 dB/m throughout its length, and that although the others have loss increases due to defects, the main regions which are free of the defects have the same uniform loss. This uniformity indicates that the 1.7 dB/m loss is not caused by the ~200 bends in each waveguide