Transmission characteristics of WDM signals amplified by semiconductor optical amplifiers in the 1.3‐µm wavelength band

Applications of semiconductor optical amplifiers to wavelength division multiplexing systems in a 1.3‐µm wavelength band are studied. The measured characteristics of gain and noise figure of the SOA, with small dependency on polarization states, confirm that it is applicable to repeater amplifiers and preamplifiers. When it is used as the preamplifier of a nonrepeated two‐channel 10 Gb/s system, an allowable line loss of 32 dB is attained with the aid of another SOA used for the postamplifier. The measured bit‐error rate of a system with one repeater amplifier is well simulated from the individual characteristics of the SOA and the optical receiver. Using a similar technique, it is predicted that more than 10 amplifiers can be applied in a system with cascaded repeater amplifiers, on the assumption that the polarization dependency of the gain is ignored. © 1998 Scripta Technica, Electr Eng Jpn, 126(1): 23–33, 1999