PRODUCT INTRODUCTION

POS-002

Polarization Tracker

The POS-002 Polarization Tracker modules maintain stable output states of polarization (SOP) against input SOP fluctuations.

MAIN SPECIFICATIONS

PRODUCT DESCRIPTION

The POS-002 polarization tracker automatically adjusts the state of polarization (SOP) towards a reference SOP, counteracting continuous input SOP variations as fast as 0.9 ms with no resets. The reference SOP is determined by a feedback signal which can be provided either internally or externally. The internal feedback version (POS-002-I) consists of a fiber squeezer polarization controller, in-line polarization monitor, digital and analog circuits, and control algorithm. The error signal from the polarization monitor is fed back to the polarization controller to maintain a linear SOP at the output. The output fiber is typically PM fiber with the SOP aligned to its slow axis.

The external feedback version (POS-002-E) replaces the internal polarization monitor with an external analog electrical feedback signal of the user’s choice, such as a voltage proportional to the degree of polarization (DOP) measured by a polarimeter, the bit-error rate (BER) from a BER chip, the RF spectrum of a detected signal, or the optical power after a polarizer. The controller adjusts the polarization to maximize the feedback signal. The output fiber is typically single mode fiber.

The function is similar to that of the POS-20X instruments, but in compact module form for integration into larger systems.

PRODUCT SOLUTIONS

The POS-002-I aligns the polarization of light to the slow axis of a PM fiber. The POS-002-E can be used to find and maintain any target polarization state as long as an optical or electrical feedback signal can be generated such that the target polarization state corresponds to the maximum value of the feedback signal.