Performance enhancement on SOA-based four-wave-mixing wavelength conversion using an assisted beam

We propose to use an additional injection beam of short wavelength to enhance the wavelength conversion that utilizes the four-wave-mixing effect in a semiconductor optical amplifier (SOA). The experiments demonstrated larger than 5-dB improvement on conversion efficiency, as the SOA is biased at the corresponding transparent condition for the assisted beam. At such a condition, an assisted beam can increase the saturation intensity without sacrificing the gain of an SOA, and this leads to an increase in conversion efficiency. The assisted beam also improves the signal-to-background-noise ratio in wavelength conversion. The effects of different assisted wavelengths and the measures for further improvement are discussed.