Attenuation makes signals weaker in fiber optic cables. Check your optical transceiver's specs often. This keeps the signal. Fiber loss, also called fiber optic attenuation or attenuation loss, refers to the loss of signal between input and output. Losses can be introduced by various means such as intrinsic material absorption, scattering, bending, connector loss and more. As depicted below, the decibel, which is used to compare two power levels in dBm, can be defined as the ratio of the optical power P o at the fiber's output to the optical power P i at the fiber's input at a specific. To determine the power budget and power margin needed for fiber-optic connections, you need to understand how signal loss, attenuation, and dispersion affect transmission.