Isolator
A fibre isolator lets light through one way only. It keeps reflections out of a laser and stops an amplifier's light running backwards.
Ports
Ports in and out. The tag on the bench shows the way it passes.
The model
\[\mathbf S_\text{in, out} = 10^{-\ell/20}\,\mathbf I, \qquad \mathbf S_\text{out, in} = 10^{-X/20}\,\mathbf I,\]with \(\ell\) its insertion loss and \(X\) its isolation, in dB. Both polarisations are treated alike, as in a polarisation-insensitive isolator.
Settings
| Field | Default | Meaning |
|---|---|---|
loss | 0.5 | Insertion loss (dB) |
iso | 40 | Isolation (dB) |
From the tool's own tables, file format version 1: the names are those in a .jekray file.
Assumptions
- The loss and isolation are flat in wavelength and the same for both polarisations.
- It adds no delay or phase of its own.
Related
- Circulator.
- Isolator, the free-space one, modelled from its polarisers and Faraday rotator.