Non-inverted multiple wavelength converter at 40 Gbit/s using 1550 nm quantum dot SOA

Error-free and low penalty (< 2.5 dB) 1 x 4 multiwavelength conversion at 40 Gbit/s in a 1550 nm quantum dot semiconductor optical amplifier (QD-SOA)is demonstrated. The suggested converter makes use of a simplified filtering scheme based on a standard telecom grade dense wavelength division multiplexing demultiplexer (Demux). By detuning the wavelength of the continuous-wave probes out of the Demux's passband, a non-inverted wavelength converted signal is available at each of the Demux's outputs. Albeit significant fibre-to-fibre losses of the non-packaged QD-SOA (similar to 10 dB), only a low penalty is reported, mainly due to the low noise at the amplifier's output, with similar performance for a single and multiple wavelength conversion operation of the setup.