Single- and Dual-Channel DPSK Signal Amplitude Regeneration Based on a Single Semiconductor Optical Amplifier

We experimentally demonstrate that,based on operational condition optimization,a common quantum well (QW) semiconductor optical amplifier (SOA) has the ability of amplitude regeneration for return-to-zero (RZ) differential phase shift keying (DPSK) signals.For a single-channel RZ-DPSK regeneration scheme,a significant eye-opening enhancement and a negative power penalty of about 1.0 dB are obtained.For dual-channel RZ-DPSK regeneration,it can also be found that the eye-opening improvement and power penalty decrease in each channel.In addition,the DPSK regeneration scheme based on a single QW SOA is quite simple and stable.