Analysis of the distortion noise due to optical fiber reflections in subcarrier-multiplexed (SCM) lightwave systems

In hybrid analog/digital optical systems based on subcarrier-multiplexing technique, the joint action of semiconductor laser chirping and multiple reflections in optical fiber gives rise to an interferometric noise affecting the performance. So far, this effect has been evaluated assuming that the delay between transmitted and reflected optical signals is so large that such signals can be considered uncorrelated, In this letter, such approximation has been overcome so that the effect due to interferometric noise can be evaluated for any distance between reflection points.