Technology Transfer SSC Pacific
Optically Clocked Optoelectronic Track and Hold Device

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Analog-to-digital converter system uses optical clock and rapid transition from tracking mode to holding mode to improve data quality and decrease interference

The U.S. Navy seeks to commercialize U.S. Patent 7,307,266 (Optically clocked optoelectronic track and hold device).


Analog-to-digital converters (ADCs) process sensory data from real-world phenomena such as sound waves or RF waves and convert them into discrete digital numbers. This conversion process allows the data to be processed, stored or transmitted in a digital form. Applications include photograph enhancement, medical diagnostic imaging, movie special effects, telephone voice and data compression, speech recognition, radar, sonar, oil and mineral prospecting and earthquake analysis. Typical analog-to-digital converters use electronic “track and hold” devices to track (measure) the incoming data signal, then hold (transmit) the outgoing digital signal. These electronic track and hold devices have considerable errors and interference, resulting in relatively low-quality digital data. An improved track and hold device would allow an analog-to-digital converter to provide higher quality digital data with less interference.

The Technology

SSC Pacific has developed a method and apparatus for an optically clocked optoelectronic track and hold device that could be used in an analog-to-digital converter to provide higher quality digital data with fewer errors. The device relies on an optical clock, which provides more accurate timing than an electronic clock, enabling the device to switch more quickly between measuring (tracking) and transmitting (holding) the analog signal. This increased rate of changing from measuring to transmitting the signal allows the device to process data more efficiently. In addition, relying on an optical clock reduces the errors in timing, known
as “jitter.” The result is an analog-to-digital conversion device that processes data more efficiently, with fewer errors and less interference, providing a clearer signal.

Key Benefits

  • Device relies on a relatively accurate optical clock, which decreases errors in timing, resulting in less “jitter” in data
  • Changes relatively quickly from tracking and holding mode, processing data more efficiently and accurately
  • Reduces the interference in the analog input signal that is typically present in devices that rely on electronic clocks
  • Development Status

  • U.S. Patent issued: 7,307,266
  • DoD 5000 Series Technology Readiness Level 2: Technology concept and/or application formulated
  • For more information on technology transfer, please contact us at (619) 5535118 or email
    SD 860, July 2009. SSC Pacific, San Diego, CA 921525001. Approved for public release; distribution is unlimited.

    SSC Pacific
    Updated: 10/25/2011 11:01 AM EST   Published