Spectral linewidth and frequency chirp of four-wave mixing components in optical fibers

The spectral characteristics of four-wave mixing components in optical fibers have been investigated both theoretically and experimentally, for the first time. The theoretical deductions show different contributions of the spectral linewidth and the frequency chirp of the signal waves to the spectrum of four-wave mixing components. Accurate spectral measurements, relying on a highly sensitive heterodyne detection system, fully confirmed the theoretical evaluations. The spectral broadening of the four-wave mixing components, due to the phase noise and the frequency chirp, may degrade the performance of unequally spaced channel HD-WDM and fiber four-wave mixing application systems.<>