All-optical power equalization based on a two-section reflective semiconductor optical amplifier.

A simple all-optical power equalization scheme based on a single two-section reflective semiconductor optical amplifier (RSOA) is presented. Double optical path and non-uniform injection current density in the two sections easily saturate the RSOA and suppress pattern effect, thereby significantly reducing packet-to-packet power fluctuation while maintaining better signal quality. The mechanism of the two-section RSOA-based power equalizer is investigated and it is indicated that the two-section RSOA biased at proper current density functions as three cascaded SOAs, including a preamplifying SOA, a gain-saturated SOA and a third SOA. The performance dependence on driven current and structural parameters is also studied.