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Title: Micro-position sensor using faraday effect

Abstract

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.

Inventors:
 [1];  [2];  [3];  [4]
  1. Livermore, CA
  2. Pittsburgh, PA
  3. Tracy, CA
  4. Brentwood, CA
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
902642
Patent Number(s):
7183765
Application Number:
10/879,222
Assignee:
The Regents of the University of California (Oakland, CA)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01D - MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION

Citation Formats

McElfresh, Michael, Lucas, Matthew, Silveira, Joseph P, and Groves, Scott E. Micro-position sensor using faraday effect. United States: N. p., 2007. Web.
McElfresh, Michael, Lucas, Matthew, Silveira, Joseph P, & Groves, Scott E. Micro-position sensor using faraday effect. United States.
McElfresh, Michael, Lucas, Matthew, Silveira, Joseph P, and Groves, Scott E. Tue . "Micro-position sensor using faraday effect". United States. https://www.osti.gov/servlets/purl/902642.
@article{osti_902642,
title = {Micro-position sensor using faraday effect},
author = {McElfresh, Michael and Lucas, Matthew and Silveira, Joseph P and Groves, Scott E},
abstractNote = {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.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2007},
month = {2}
}

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Works referenced in this record:

The Faraday Effect
journal, January 1999


Fiber Optic Sensors: An Overview
journal, April 1985