The POS-202, POS-203 and POS-204 polarization stabilizers maintain  stable output states of polarization (SOP) against rapid input SOP fluctuations, compensating for an input polarization discontinuity in as fast as 5 ms, or tracking without resets against a continuous input SOP rotation of up to 32π/s. The POS-20X architecture includes a polarization controller, in-line polarization monitor, and proprietary algorithms.

The POS-202 has optical ports for signal input and output. It stabilizes the output SOP to linear, aligned to the slow axis of the output PM fiber.