The proposed research is a collaborative project between M. Raymer at the University of Oregon and T. Plant at Oregon State University. The new research will address spatial propagation of quantum light fields in traveling-wave semiconductor amplifiers and superluminescent sources. Experiments will be designed to probe questions concerning quantum noise in situations that are not equivalent to cavity lasers, and that will challenge theorists to go beyond the typical photon rate- equation models now being applied to similar problems. The broad goal of the proposed research is to understand from a fundamental viewpoint some of the intrinsic interactions and mechanisms responsible for the quantum fluctuations of devices using semiconductor gain media, and to learn the implications of these fluctuations for amplifier and SLD operation. Traveling-wave amplifiers will be studied which have long (5-10mm) active regions, defined by either a single long contact or multiple (segmented) contacts on a single wafer. By using long amplifier structures attempts will be made to observe the effects of gain saturation and amplitude-to-phase coupling on the optical spectrum and intensity fluctuations of these sources. The studies will also focus on whether saturation of a properly designed amplifier can lead to intensity stabilization of the output of a SLD. The OSU group will provide expertise in fabrication and characterization of semiconductor amplifiers and the UO group will carry out noise measurements and theoretical modeling.