The backscattering method is also employed in fiber optics applications to detect optical faults. Light propagating through a fiber-optic cable gradually attenuates due to Rayleigh scattering. Faults are thus detected by monitoring the variation of part of the Rayleigh backscattered light. Since the backscattered light attenuates exponentially as it travels along the optical fiber cable, the attenuation characteristic is represented in a logarithmic scale graph. If the slope of the graph is steep, then power loss is high. If the slope is gentle, then optical fiber has a satisfactory loss characteristic.
The loss measurement by the backscattering method allows measurement of a fiber-optic cable at one end without cutting the optical fiber hence it can be conveniently used for the construction and maintenance of optical fibers.