Fiber-Optic Long-Line Position Sensor

Technology Summary

Sandia National Laboratories has developed a side-emitting fiber optic position sensor and method of determining an unknown position of an object by using the sensor.  Non-electrical position sensors like the one developed by Sandia are desirable for use in hazardous environment, e.g., for measuring the liquid level in gasoline or jet fuel tanks.  This sensor is an attractive option because it does not introduce electrical energy, is insensitive to electromagnetic interference, has very few moving parts, and could provide continuous measurements.


Large-scale rotary drilling for oil and gas, minerals, and water wells have a need for measuring the depth of drill bits and pipe segments.  Measuring the length of a cable played out is often inaccurate because the cable stretches under heavy loads.  There is a need for a long-range position sensor that is non-contact, simple, inexpensive, reliable, compact, non-electrical, and robust.  These and other features have been achieved in the present Sandia invention.


  • Sensor does not introduce electrical energy and is insentive to electro-magnetic interference
  • Does not require the use of florescent dopants
  • Can operate over a wide range of wavelengths at a reduced cost
  • Has very few moving parts
  • Provides continuous measurement

Applications and Industries

  • Oil and Gas
  • Minerals
  • Water Wells
  • Fuel Tank Measurement
  • Hazardous Environments

Intellectual Property

ID Number
Patent Number
Side-emitting fiber optic position sensor 10001.1 7,329,857 02/12/2008
Technology IDPatent# 7,329,857/ SD# 10001Development StagePrototype - Sandia estimates this technology at a TRL 5. Key elements of the technology have been demonstrated in relevant environments. AvailabilityAvailable - Various licensing and partnering options are available. Please contact the Intellectual Property department to discuss.Published09/29/2011Last Updated02/04/2013