An ultrawide-band semiconductor optical amplifier having an extremely high penalty-free output power of 23 dBm achieved with quantum dots

A semiconductor optical amplifier (SOA) having a gain of > 25 dB, noise figure of < 5 dB, and 3-dB saturation output power of > 19 dBm, over the record widest bandwidth of 90 nm among all kinds of optical amplifiers, and also having a penalty-free output power of 23 dBm, the record highest among all the SOAs, was realized by using quantum dots.