Because of the phase noise fluctuation at the output of a semiconductor laser
the transimited optical signal experiencing multiple reflections from fiber interface will becoherently superposed with a delayed version of itself. This can produce intensity noisefluctuation due to phasc--to--intensity conversion. The effects of Interferometric noise onthe EFM optic-links must be considered due to the high data rate. In this paper
we ana-lyze the effects of interferometric noisc on the system performance and its power penalty.