All-Optical Semiconductor Optical Amplifier-Based Wavelength Converters With Sub-mW Pumping

We experimentally study the wavelength conversion of 10-Gb/s return-to-zero signal using interband four-wave mixing inside a semiconductor optical amplifier with 10-ps gain-recovery time. Power of the converted signal exceeds that of the original signal for wavelength shifts of up to 8 nm. Our technique is energy efficient as the required input pump power is
${<}{\rm 1}~{\rm mW}$
. We discuss the observed performance of such a wavelength converter in terms of required pump power, conversion efficiency, and optical signal-to-noise ratio of the converted signal. For an 8-nm wavelength shift, the converted data signal exhibits no Q-factor degradation while having 2.7-dB power gain.