Laser mode partitioning and mode evolution effects in high-speed fiber-optic transmission

The chromatic dispersion of light emitted from multilongitudinal mode lasers can seriously degrade a high-speed fiber-optic system. The predominant impairments are mode partition noise1,2 and a new phenomenon, intersymbol interference caused by modal evolution. We have used a combination of experimental measurements of laser properties and numerical modeling to obtain accurate estimates of the system penalty caused by either effect. System tests in a fiber-optic link confirmed the validity of our analysis.