For multimode fiber, the loss is about 3 dB per km for 850 nm sources, 1 dB per km for 1300 nm. 5 dB/km max per EIA/TIA 568) This roughly translates into a loss of 0. Optical fiber loss refers to the decrease in optical power due to absorption and scattering after optical signals are transmitted through optical fibers. When implementing optical fiber communication, a key challenge is minimizing the loss of signals within the fiber. Both the TIA and ISO cabling standards list the acceptable loss limits for fiber optic components, and these values are. OSN 2500 Intelligent Optical Switching System OptiX OSN 2500: Access product manuals, HedEx documents, product images and visio stencils.