Micro-position sensor using faraday effect

Patent · Mon Feb 26 23:00:00 EST 2007

OSTI ID:902642

McElfresh, Michael ^[1]; Lucas, Matthew ^[2]; Silveira, Joseph P ^[3]; Groves, Scott E ^[4]

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1. Livermore, CA
2. Pittsburgh, PA
3. Tracy, CA
4. Brentwood, CA

A micro-position sensor and sensing system using the Faraday Effect. The sensor uses a permanent magnet to provide a magnetic field, and a magneto-optic material positioned in the magnetic field for rotating the plane of polarization of polarized light transmitted through the magneto-optic material. The magnet is independently movable relative to the magneto-optic material so as to rotate the plane of polarization of the polarized light as a function of the relative position of the magnet. In this manner, the position of the magnet relative to the magneto-optic material may be determined from the rotated polarized light. The sensing system also includes a light source, such as a laser or LED, for producing polarized light, and an optical fiber which is connected to the light source and to the magneto-optic material at a sensing end of the optical fiber. Processing electronics, such as a polarimeter, are also provided for determining the Faraday rotation of the plane of polarization of the back-reflected polarized light to determine the position of the magnet relative to the sensing end of the optical fiber.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• Sponsoring Organization: United States Department of Energy
• DOE Contract Number: W-7405-ENG-48
• Assignee: The Regents of the University of California (Oakland, CA)
• Patent Number(s): 7,183,765
• Application Number: 10/879,222
• OSTI ID: 902642
• Country of Publication: United States
• Language: English

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