Suppressing EDFA Transient Effects Using Polarization Multiplexing

A novel method for suppressing transient effects in an erbium-doped fiber amplifier (EDFA) is proposed and experimentally demonstrated. By employing polarization multiplexing, an amplitude-fluctuating signal and its amplitude-complementary counterpart are simultaneously modulated onto two orthogonal polarization states of the optical carrier. As a result, the total power of the optical carrier remains stable, even though it carries an amplitude-varying signal. Consequently, when this signal is transmitted through an optical link that includes an EDFA, the transient effects of the EDFA are effectively suppressed. In a proof-of-concept experiment, pulse signals with various repetition rates and duty cycles were transmitted without distortion after amplification by the EDFA using the proposed scheme. The proposed approach is applicable to periodic control signals, pulsed single-frequency signals, and wideband pulsed waveforms in EDFA-based optical links, which are essential for radio-over-fiber and microwave photonic systems.