Optical Comm
Systems

HAVE LACE and Free Space Communications
In this Air Force program in the late 1980’s, GTE/EOO designed, integrated, and demonstrated a laser communication system at 19.2 kbits/sec for transmission of voice or data between two 4950th Test Wing KC-135 aircraft at ranges out to 100 miles. Laser diode transmitters were used with a pulse position mode Hamming (7,4) code employed to compensate for scintillation interrupts. This effort and a great deal of other high data rate satellite cross link and up/down link experience has been used by EOO in several system concept definition studies for the government and other potential users of the very high data rates (multi-gigabits) that laser links support. The promise of nearly unlimited bandwidth and ultra-secure links is just now beginning to be realized after nearly 40 years of false starts by the US Government, the Europeans and the Japanese. Commercial ventures such as Teledesic have also been interested in Laser crosslinks, but no one has been successful in overcoming the challenging pointing  and packaging constraints. As similar technology is required for Optical Radar and fiber optic communications, and great advances in are being made in each area, free space optical communications will benefit and could yet live up to expectations. Short range terrestrial atmospheric links are being used more and more, and they could provide the solution for the “last mile” bottleneck in many telecommunication networks. EOO still supports work in the Optical Communication area.

SUBMARINE LASER COMMUNICATIONS and Scattered Light Communications
Since 1977, GTE/EOO has been continuously involved in the blue-green submarine laser communication (SLC) program, including systems engineering, technology development, and the design, development, and support of field test hardware. A key feature of this work involves the use of pulse position modulation with pseudo-random coding for very low signal level link closure. This leads to the possibilty of LPI/LPD operation. In addition, understanding the water propagation channel and how scattering and absorption affects communication performance are critical. This experience is being used for on-going Underwater Laser Communication Study programs at EOO. The DARPA/Navy SLC program and its variants have been dormant for more than 10 years. However, renewed interest has been generated for such applications as links to Underwater Autonomous Vehicles and other underwater sensors. A Program called MILS, for Multi-Integrated Laser Sensor, has been proposed by EOO and Northrop Grumman’s Newport News Shipbuilding for placing a suite of electro-optic equipment on board a submarine which provides for remote sound velocity profile measurement, hard target ranging, wake detection, underwater imaging and laser communications all with the same suite of equipment. Potential Navy sponsors have expressed interest. NavSea has shown particular interest in the sound velocity measurement capability and has included the concept in its long range Design Improvement Program (DIP) for Virginia Class submarines. Related work as a subcontractor to a nationally known Research Center to explore Lasercom at great depths is in its early stages.

UNDERWATER NEPHELOMETER
The goal of this Phase II SBIR effort was to develop a laboratory prototype device that could measure the volume scattering function and the beam attenuation coefficient of marine and other bodies of water. Such data can be used to predict and improve the performance of Navy optical systems, including submarine laser communications, underwater imagers, and LIDAR systems. We have also identified applications in ocean research and engineering and water pollution control and mitigation. No other device can make such measurements operationally. EOO was a subcontractor to Global Associates in the early to mid 1990’s with responsibility for the design, development, integration, and test of the wet-side electro-optical instrument head. The Prime was responsible for customer interface, mission planning, and the software and computer for data processing and display.


For More Information, you may contact Dan Radecki at:
269 N. Mathilda Avenue
Sunnyvale, CA 94086
Phone: (408) 738-5393
Fax: (408) 738-5399
E-mail: info@eooinc.com