High-Speed Polarization Analysis in Recirculating Loops
Recirculating loop experiments are a powerful tool for simulating long-haul transmission in optical communication. A typical setup is shown in the figure on the right-hand side. In this way, transmission distances of 1000km and more can be simulated in the lab without using huge amounts of fibers and amplifiers.
To obtain a realistic behavior, special care has to be taken on: Polarization, PMD, PDL. These effects can cause strong unrealistic behavior mainly because the light passes exactly the same fiber spool and the same EDFA(s) multiple times.
These effects can be mitigated in different ways. One way is to adjust a manual polarization controller inside the loop causing the polarization state to jump on every revolution. Better results are achieved by actively scrambling the polarization inside the loop either asynchronous or synchronous to the loop cycles.
Adaptif PHOTONICS offers comprehensive solutions for optimizing recirculating loops:
- High-speed polarization analysis with up to 1MHz sampling rate:
See the Stokes parameters of your signal changing with each revolution.
See your OSNR changing with each revolution.
Removes deterministic scaling effects for PMD/PDL.

