Terminator
A terminator ends a fibre cleanly. It absorbs the light that arrives and sends back only what its return loss lets through. It closes an unused port of a coupler.
Ports
One port, in.
The model
For a return loss \(\mathrm{RL}\) (dB), the light reflected back is
\[\mathbf S_{11} = 10^{-\mathrm{RL}/20}\,\mathbf I,\]\(10^{-\mathrm{RL}/10}\) of the power. At the default 60 dB that is a millionth.
A port left open, with no fibre and no terminator, also takes in what reaches it and reflects nothing. A terminator is the way to give it a reflection, or to show on the bench that the port is ended.
Settings
| Field | Default | Meaning |
|---|---|---|
rl | 60 | Return loss (dB) |
From the tool's own tables, file format version 1: the names are those in a .jekray file.
Assumptions
- Its reflection is flat in wavelength and the same for both polarisations.
Related
- Fibre optics: along a fibre, for the reflections of a fibre’s own ends.
- Attenuator.