External-pump-free polarization-insensitive wavelength converter with fast wavelength switching using orthogonal pumps four-wave mixing in a semiconductor optical amplifier

We demonstrate polarization-insensitive widely tunable wavelength conversion using broad-band orthogonal pumps four-wave mixing in a semiconductor optical amplifier placed inside a double-ring fiber cavity without any external-pump. A 3-dB conversion range over 40 nm is obtained with smaller than 0.5-dB polarization sensitivity using the scheme of polarization diversity. The measured power penalty is 3 dB for a 10 Gb/s signal at 10/sup -9/ bit-error rate level. In order to probe the response of the fiber-laser-based wavelength converter, the switching dynamics of the converted signal in a basic single-ring configuration have been investigated. The results show fast responses for both ON/OFF and wavelength switching of the converted signal within a few round-trip cycles.