Approximately 70 percent of the world's surface is ocean, and the ocean remains one of the last frontiers for exploration. This exploration is hampered by the lack of high band width communications. Radio waves do not propagate in sea water, and acoustic communication systems operate at relatively low bandwidth. Recent developments in blue/green semiconductor light sources suggest an alternative technology path to high bandwidth underwater optical communications.
Intellectual Merit: The technical challenge of this proposal is to understand how the propagation of light underwater impacts optical communication system design and to develop methodologies to compute accurate communication link budgets for different ocean water conditions. To accomplish this, underwater optical communication systems will be built and tested in different water conditions. Understanding the role of absorption and scattering on the attenuation and dispersion of the signal is especially important to quantify. The scattering of light underwater also places special requirements on the dynamic range of the receiver, as well as the collection optics and pointing requirements. In addition to underwater optical communication links, short range optical wireless links integrated with solid state lighting systems and autonomous robotic vehicles will be considered.
Broader Impact: High bandwidth underwater communications would be enabling for many scientific disciplines that investigate the ocean environment. Presently there is a proliferation of research that relies on autonomous underwater vehicles for data collection, and increasing numbers of people and robots work underwater, performing surveys, examining cables and pipelines, or working on oil rigs. Working underwater is dangerous and difficult and is consistently hampered by poor communications. The proposal also has a strong outreach component that involves numerous undergraduates in the underwater robotics club, and senior design program. The community is involved in the proposal through interaction with community college and middle school students.
