FSO link budget calculator

Work out whether an optical link closes over your distance, in your weather. The model combines geometric beam spreading, atmospheric attenuation and turbulence-induced scintillation, and reports the margin left over your receiver sensitivity.

Start from a product

Picking a variant fills in its optical parameters. You can still change anything afterwards.

Link geometry

Optical parameters

The maximum input the receiver tolerates. Over a short link the beam can deliver more power than this and saturate it. Every overload figure we hold is a proposed-candidate value, not a measured one — treat this as an advisory.

Atmosphere

Additional losses

Received power
—
Link margin
—
Overload clearance
—
Estimated max range
—

Margin against distance

Each curve is one weather condition. Where a curve crosses zero, the link stops closing.

Clear air Haze Heavy rain Light fog Dense fog

Link budget

  • Transmit power—
  • Geometric loss—
  • Atmospheric loss—
  • Scintillation loss—
  • System and optics loss—
  • Pointing loss—
  • Received power—
  • Receiver sensitivity—
  • Raw margin above sensitivity—
  • Required reserve—
  • Link margin—
  • Specific attenuation—

Send this configuration to us

We will review the budget against a real deployment and tell you honestly whether it will hold.

Send configuration
This is a planning tool. It gives a well-founded estimate, not a guarantee of availability — a real deployment also depends on mounting rigidity, alignment, window losses and local climate statistics.

Margin across weather

The same link, evaluated against each condition at your chosen distance.

Condition Visibility Attenuation Margin Overload Max range Link