Browse Prior Art Database

High Resolution Magnetic Field Measurement Device

IP.com Disclosure Number: IPCOM000102068D
Original Publication Date: 1990-Oct-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Goodman, DS: AUTHOR [+2]

Abstract

Disclosed is a magnetic field measuring device which will measure the field with a spatial resolution of the order of light wavelengths.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 72% of the total text.

High Resolution Magnetic Field Measurement Device

       Disclosed is a magnetic field measuring device which will
measure the field with a spatial resolution of the order of light
wavelengths.

      Referring to Figs. 1 and 2, light from a polarized laser 1 is
focussed with lens 2 on one end 3 of a polarization preserving
optical fiber 4.  The light is conducted down the fiber 4 to a
magneto-optically active crystal 5 located at the far end of the
fiber 6.  The crystal 5 can be bonded to the fiber end 6 with optical
cement 7.  The light continues through the crystal 5 to another
polarization preserving optical fiber 8, where the optical axis of
fiber 4 and fiber 8 are aligned perpendicularly to each other.
Additionally, crossed polarizers 9 and 10 could be placed on either
side of the crystal 5 to ensure that crosstalk between the
polarization modes would not disturb the measurements.   In absence
of magnetic field, no light would propagate down fiber 8 to be
detected at detector 11.  As the magnetic field is increased, the
crystal 5 will rotate the plane of polarization, and the light will
pass to detector 11.  The light detected will be, to first order,
proportional to the magnetic field.

      Alternatively, a single polarization preserving fiber 12 (see
Fig.  3) could conduct light from a laser 13, beamsplitter 14 and
lens 15 to a magneto-optic crystal 16 with an optional polarizer 17
lined up with the polarization axis of the fiber 12.  The
mag...