An ultrawide-band (120 nm) semiconductor optical amplifier having an extremely-high penalty-free output power of 23 dBm realized with quantum-dot active layers

A semiconductor optical amplifier having a gain of >20 dB, noise figure of >7 dB, and 3-dB saturation output power of >19 dBm, over the record widest bandwidth of 120 nm among all kinds of optical amplifiers, and also having a penalty-free output power of 23 dBm, the record highest among all the semiconductor optical amplifiers, was realized by using quantum dots.