Cable attenuation represents the inherent loss of signal power that occurs as light travels along the fiber. Losses can be introduced by various means such as intrinsic material absorption, scattering, bending, connector loss and more. The. Optical fiber loss is a fundamental concept in fiber optic communications, representing the attenuation of light signals as they travel through fiber optic cables. Fiber. To be able to judge whether a fiber optic cable plant is good, one does a insertion loss test with a light source and power meter and compares that to an estimate of what is a reasonable loss for that cable plant. In summary, fiber optic loss is.