Magnetic field measuring apparatus

Patent metadata

Field	Value
Publication number	US-9360534-B2
Application number	US-201514589457-A
Country	US
Kind code	B2
Filing date	Jan 5, 2015
Priority date	Oct 29, 2009
Publication date	Jun 7, 2016
Grant date	Jun 7, 2016

Abstract

A beam that passes through a plurality of gas cells a number of times is led to a deflection meter from a light ejecting section, detection of a deflected surface angle is performed and a strength of a magnetic field is measured by a structure in which the plurality of the gas cells is arranged along a light beam between two reflection units or light concentrating units that have a light beam incidence section and a light beam ejecting section and are opposite to each other, and a laser beam that is incident from the light beam incidence section passes through the plurality of the gas cells and then is multiply reflected by both reflection units.

First claim

What is claimed is:

1. A magnetic field measuring apparatus comprising:
a probe irradiation unit that irradiates a probe light having a straight polarization;
a first reflection unit that reflects the probe light;
a first cell that includes vapor of first alkali metal atoms therein;
a second reflection unit that is different from the first reflection unit and that reflects the probe light; and
a second cell that is different from the first cell and that includes vapor of second alkali metal atoms, wherein
the probe light irradiation unit, the first cell, the second cell, and the second reflection unit are arranged in this order along with a probe light path so that the probe light irradiation unit and the second reflection unit are located at outer most positions along with the probe light path and the first and second cells are sandwiched by the first reflection unit and the second reflection unit with air gaps,
a number of passage times of the probe light through the first and second cells are the same,
a first reflection surface of the first reflection unit and a second reflection surface of the second reflection unit are parallel to each other, and
the first reflection surface includes a plurality of passages for prove lights to pass through, such that the prove lights pass through the plurality of passages in either a direction toward the first reflection surface or in a direction away from the first reflection surface.

2. The magnetic field measuring apparatus according to claim 1 , further comprising:
a pump light irradiating unit that irradiates first and second pump lights toward the first and second cells, respectively, wherein
the first and second pump lights are circular polarized so that a magnetization direction in the first cell is opposite to a magnetization direction in the second cell.

3. The magnetic field measuring apparatus according to claim 2 , further comprising:
a light detection unit that detects the probe light passes through both the first and second cells, wherein
the light detection unit is located directly adjacent to one of the first cell and the second cell.

4. The magnetic field measuring apparatus according to claim 3 , wherein
the probe light irradiation unit, the first reflection unit, the first cell, the second cell, and the second reflection unit are arranged in a first direction along with a linear line, and
a measurement object is located on the linear line, and the measurement object is located nearer to one of the first cell and the second cell.

5. The magnetic field measuring apparatus according to claim 3 , wherein
the light detection unit is located directly adjacent to the probe light irradiating unit and the first reflection unit.

6. The magnetic field measuring apparatus according to claim 5 , wherein
the probe light irradiation unit, the first reflection unit, the first cell, the second cell, and the second reflection unit are arranged in a first direction along with a linear line, and
a measurement object is located on the linear line, and the measurement object is located nearer to one of the first cell and the second cell.

7. The magnetic field measuring apparatus according to claim 2 , wherein
the probe light irradiation unit, the first reflection unit, the first cell, the second cell, and the second reflection unit are arranged in a first direction along with a linear line, and
a measurement object is located on the linear line, and the measurement object is located nearer to one of the first cell and the second cell.

8. The magnetic field measuring apparatus according to claim 1 , further comprising:
a light detection unit that detects the probe light passes through both the first and second cells, wherein
the light detection unit is located directly adjacent to one of the first cell and the second cell.

9. The magnetic field measuring apparatus according to claim 8 , wherein
the light detection unit is located directly adjacent to the probe light irradiating unit and the first reflection unit.

10. The magnetic field measuring apparatus according to claim 9 , wherein
the probe light irradiation unit, the first reflection unit, the first cell, the second cell, and the second reflection unit are arranged in a first direction along with a linear line, and
a measurement object is located on the linear line, and the measurement object is located nearer to one of the first cell and the second cell.

11. The magnetic field measuring apparatus according to claim 8 , wherein
the probe light irradiation unit, the first reflection unit, the first cell, the second cell, and the second reflection unit are arranged in a first direction along with a linear line, and
a measurement object is located on the linear line, and the measurement object is located nearer to one of the first cell and the second cell.

12. The magnetic field measuring apparatus according to claim 1 , wherein
the probe light irradiation unit, the first reflection unit, the first cell, the second cell, and the second reflection unit are arranged in a first direction along with a linear line, and
a measurement object is located on the linear line, and the measurement object is located nearer to one of the first cell and the second cell.

13. The magnetic field measuring apparatus according to claim 12 , further comprising:
a light detection unit that detects the probe light passes through both the first and second cells, wherein
the light detection unit is located directly adjacent to one of the first cell and the second cell.

14. The magnetic field measuring apparatus according to claim 13 , wherein
the light detection unit is located directly adjacent to the probe light irradiating unit and the first reflection unit.

Assignees

• Seiko Epson Corp

Inventors

• Nagasaka Kimio

Classifications

• G01R33/0322 Primary

  using the Faraday or Voigt effect · CPC title

• G01R33/24

  for measuring direction or magnitude of magnetic fields or magnetic flux · CPC title

• G01R33/26

  using optical pumping · CPC title

• G01R33/0327

  with application of magnetostriction · CPC title

• G01R33/032 Primary

  using magneto-optic devices, e.g. Faraday {or Cotton-Mouton effect} · CPC title