Semiconductor optical amplifiers for all-optical wavelength conversion

All-optical wavelength conversion is one of the key functionalities in wavelength division multiplexed (WDM) systems, where channel routing is desired without any limitation. Semiconductor optical amplifiers offer several possible solutions for this functionality in the optical domain. Different possible solutions are compared, pointing out the advantages and disadvantages of each. Then, a simple, but most promising, method, cross-gain modulation, is investigated through performance measurement results. The saturation of the amplifier, conversion nonlinearity and signal extinction ratio after conversion are also investigated and presented.