Work out fibre optic loss budget instantly with clear inputs, formula shown and shareable results.
A fibre loss budget adds attenuation per kilometre to the loss of each connector pair and splice. Single-mode fibre loses about 0.35 dB per km at 1310 nm and 0.22 at 1550, while connectors cost roughly 0.5 dB each and fusion splices only 0.1. TIA guidance is to add about 3 dB of margin for ageing, repairs and temperature.
Loss budget
total = length x attenuation per km + connector pairs x 0.5 dB + splices x 0.1 dB; add 3 dB margin
Its attenuation is the lowest of the standard windows, about 0.22 dB per km, which extends reach substantially and is also where erbium-doped amplifiers operate.
A connector is a mechanical mating with an air gap and alignment tolerance; a fusion splice welds the cores together. Contamination on a connector face can add several dB.