10-Gb/s RZ-DPSK transmitter using a saturated SOA as a power booster and limiting amplifier

The performance of a semiconductor optical amplifier (SOA) in the deep saturation regime is studied for single-channel return-to-zero (RZ) and nonreturn-to-zero differential phase-shift keying (DPSK) and on-off keying signals at 10 Gb/s. It is found that saturated SOAs can be used as power boosters and limiting amplifiers for RZ-DPSK transmitters with almost no compromise of performance.