Polarization properties of a reflective fiber amplifier employing a circulator and a Faraday rotator mirror

We present a detailed study of the polarization properties of a reflective fiber amplifier composed of a circulator, a normal single-mode Er-doped fiber and a Faraday rotator mirror. The amplifier can preserve an arbitrary input state of polarization regardless of any external perturbations, and is completely free from polarization effects. The effect of imperfections of the Faraday rotator mirror is also discussed. Finally, we demonstrate experimentally the polarization-stability of the amplifier and its ability to compensate polarization mode dispersion both in the circulator and in the single-mode Er-doped fiber.