WITH NEW THEORY and experimental techniques, optical communications and imaging systems could approach the limits of informationencoding efficiency. Reaching that level is the goal of Raytheon BBN Technologies, which has been awarded $2.1 million in funding by the Defense Advanced Research Projects Agency (DARPA) for two projects under the Information in a Photon (InPho) program. It plans to develop new sources of quantum-entangled light as well as novel optical-sensor technologies.

In the first project, Photon Information Efficient Communications (PIECoMM), Raytheon BBN Technologies will generate and demonstrate experimental solutions that attain data communications at 10-b/ photon and 5-b/s/hz. Examples include multiple-spatial-mode design and adaptive joint-detection receivers. This work will be done with researchers in optical communications, quantum optics, and information theory at the Massachusetts Institute of Technology (MIT). If this goal is achieved, it will significantly improve power management, speed, and reach for free-space optical-communication linksincluding the far-field links used in deep space.

The second project, dubbed Fundamental Information Capacity of Electromagnetism with Squeezing and Spatial Entanglement (FINESSE), will explore the theoretical performance limits for imaging technology as determined by the laws of quantum physics. In collaboration with the University of Virginia, Raytheon BBN Technologies will conduct a program investigating newly engineered quantum states of light. The goal is to achieve imaging performance that is superior to conventional techniques.