Polarization stabilizer using liquid crystal rotatable waveplates

In standard single-mode fiber (SMF) transmission systems, a polarization st abilizer is useful for optimizing the performance of polarization dependent systems or devices. We have proposed and developed a polarization stabiliz er which employs liquid crystal (LC) rotatable waveplates, It has a simple configuration, no moving parts, and endless-control characteristic. High po larization stability was confirmed under various state of polarization (SOP ) fluctuations. The maximum response speed of the polarization stabilizer i s about 900 degrees/s, but this can be increased by improving the controlle r. We applied the polarization stabilizer to a semiconductor optical amplif ier (SOA) having polarization dependence, and achieved good gain stabilizat ion.