#telecom

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.

api.oanor.com/opticalbudget-api

Optical-fibre photonics maths as an API, computed locally and deterministically. The numerical-aperture endpoint computes a step-index fibre's numerical aperture NA = √(n1² − n2²) from the core and cladding refractive indices, the acceptance angle θa = arcsin(NA) — the half-angle of the cone of light the fibre can capture — the full acceptance cone and the relative index difference Δ = (n1 − n2)/n1. The v-number endpoint computes the normalized frequency V = 2π·a·NA/λ from the core radius, the numerical aperture (or the indices) and the wavelength, classifies the fibre as single-mode when V is below the 2.405 cutoff or multimode above it, and gives the cutoff wavelength for single-mode operation. The modes endpoint estimates the number of guided modes — about V²/2 for a step-index fibre and V²/4 for a graded-index one — and confirms single-mode operation below the cutoff. Core radius and wavelength are in metres (1310 nm = 1.31×10⁻⁶ m) and refractive indices are dimensionless. Everything is computed locally and deterministically, so it is instant and private. Ideal for telecom, photonics, datacenter, sensor and laser app developers, fibre-link and waveguide-design tools, and optics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is optical-fibre guiding; for thin lenses and mirrors use a lens API and for refraction at a surface a Snell API.

api.oanor.com/fiber-api