Fiber Optic Link Budget API

Fiber-optic link-budget engineering maths as an API, computed locally and deterministically — the power-budget, loss and reach numbers a network or fibre engineer designs an optical link with. The power-budget endpoint gives the optical power budget = transmit power − receiver sensitivity (in dBm), the total loss the link can tolerate: a 0 dBm transmitter into a −23 dBm receiver gives a 23 dB budget, with the powers also shown in milliwatts. The loss endpoint adds up the real link loss from the fibre attenuation × length plus the connector and splice losses — single-mode fibre runs about 0.35 dB/km at 1310 nm and 0.20 dB/km at 1550 nm, each mated connector ~0.5 dB and each fusion splice ~0.1 dB — so 10 km of fibre with two connectors is 4.5 dB. The reach endpoint gives the maximum distance = (power budget − fixed losses − system margin) ÷ the fibre attenuation, reserving a margin (typically 3 dB) for ageing, bends and future repair splices so the link still works years on. Everything is computed locally and deterministically, so it is instant and private. Ideal for FTTx and data-centre link planning, network-engineering and OSP tools, fibre-survey and design utilities, and telecom calculators. Pure local computation — no key, no third-party service, instant. Loss-limited model — at high bit rates dispersion can cap distance first. 3 compute endpoints. For fibre numerical aperture and photonics use a fiber API; for RF line-of-sight a Fresnel-zone API.