Abstract

Reflections at discontinuities in connectors, splices, and components are known to cause impairments in fiber transmission systems. For example, an air gap between connector endfaces can reflect as much as 22% of the incoming power backward to the laser, ¹ causing reflection-induced noise and other degradations.² These effects can be minimized by incorporating an optical isolator in the laser package. However, it has recently been observed that such discontinuities can also form Fabry-Perot cavities which convert the phase noise of semiconductor lasers into high levels of intensity noise downstream of the isolator.³'⁴ We discuss the impact of this interferometric noise on direct detection systems and compare our theoretical predictions with measured power penalties.

© 1988 Optical Society of America