Computer simulations and noise analysis of system performance of 1.55micron single-frequency semiconductor lasers.

Computer simulations are used to analyze the system performance of 1.55micron InGaAsP single-frequency lasers. The bit-error- rate curves generated from our computer simulation agree well with the results of transmission experiments. The relative contribution of various noise sources to the limitation of laser system-performance is discussed and compared. Noise contribution from any noise source other than circuit noise and shot noise may lead to the appearance of a noise floor in bit-error-rate curves and sets a limit to the transmission distance. Our analysis shows that at low bit rates the transmission distance is loss limited, while at high bit rates it is limited by transient wavelength chirp. Other noise sources do not impose any limitation on transmission distance, although they may introduce some power penalties to the receiver sensitivity. In order to realize the transmission distance at the fiber loss limit at high bit rates future development work in single- frequency lasers should concentrate on reducing transient wavelength chirp.