Diverging waveguide atomic gyroscope

Patent metadata

Field	Value
Publication number	US-9766071-B2
Application number	US-201514717782-A
Country	US
Kind code	B2
Filing date	May 20, 2015
Priority date	Jan 23, 2015
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

Waveguide includes fork with first and second bifurcated ends coupled to loop section and separated by angle determined based on velocities of portions of quantum mechanical wavefunction of atoms traveling above waveguide. Waveguide propagates blue-detuned laser having first evanescent field that repels atoms away from waveguide and red-detuned laser having second evanescent field that attracts atoms toward waveguide, together creating potential minimum/well. Laser cooling atoms, causing atoms positioned in potential minimum/well to move toward first fork section following potential minimum/well. Atomic state initialization section initializes atomic states of atoms to known ground-state configuration. Beam splitter section splits quantum mechanical waveform of each atom above surface of diverging waveguide into first portion at first velocity that travels into first end of first fork section into first loop section and second portion at second velocity that travels into second end of first fork section into first loop section.

First claim

What is claimed is:

1. A diverging waveguide including:
a first section having a first end and a second end opposite the first end;
a first fork section having a first single end, the first fork section also having a first bifurcated end and a second bifurcated end opposite the first single end, the first single end of the first fork section coupled to the first end of the first section, the first fork section configured with a first angle between the first bifurcated end and the second bifurcated end, the first angle determined based on velocities of portions of a quantum mechanical wavefunction of atoms configured to travel above the waveguide; and
a first loop section having a first loop end and a second loop end, the first loop end coupled to the first bifurcated end of the first fork section and the second loop end coupled to the second bifurcated end of the first fork section;
wherein the diverging waveguide is configured to propagate a blue-detuned waveguide laser light, the blue-detuned waveguide laser light at a first frequency above a resonant atomic frequency of atoms above a surface of the diverging waveguide, the blue-detuned laser light having a first evanescent field that extends above the surface of the diverging waveguide a first distance, the first evanescent field repelling the atoms away from the surface of the diverging waveguide;
wherein the diverging waveguide is configured to propagate a red-detuned waveguide laser light, the red-detuned waveguide laser light at a second frequency below the resonant atomic frequency of the atoms above the surface of the diverging waveguide, the red-detuned laser light having a second evanescent field that extends above the surface of the diverging waveguide a second distance that is greater than the first distance, the second evanescent field attracting the atoms toward the surface of the diverging waveguide;
wherein the first evanescent field and the second evanescent field create a potential minimum/well above the surface of the diverging waveguide, wherein the atoms are suspended in the potential minimum/well;
wherein the first section of the diverging waveguide includes:
a laser cooling section positioned between the first end of the first section and the second end of the first section, the laser cooling section configured to cool at least a first group of the atoms down in a transverse direction to the first section of the diverging waveguide, causing the at least the first group of the atoms positioned in the potential minimum/well above the surface of the diverging waveguide to move in a first longitudinal direction toward the first fork section following the potential minimum/well above the surface of the diverging waveguide;
a first atomic state initialization section positioned between the laser cooling section and the first fork section, the first atomic state initialization section configured to initialize atomic states of the at least the first group of the atoms moving in the first longitudinal direction following the potential minimum/well above the surface of the diverging waveguide to a known ground-state configuration; and
a first beam splitter section positioned between the first atomic state initialization section and the first fork section, the first beam splitter section configured to split a quantum mechanical wavefunction of each atom of the at least the first group of the atoms moving in the first longitudinal direction following the potential minimum/well above the surface of the diverging waveguide into a first portion having a first velocity and a second portion having a second velocity different than the first velocity, wherein the first portion travels into the first bifurcated end of the first fork section of the diverging waveguide and into the first loop end of the first loop section, and wherein the second portion travels into the second bifurcated end of the first fork section of the diverging waveguide and into the second loop end of the first loop section.

2. The diverging waveguide of claim 1 , wherein the laser cooling section includes:
at least one cooling laser source configured to generate at least one cooling laser field, wherein the velocity of the atoms is reduced when the atoms attempt to move against the at least one cooling laser field of the at least one cooling laser source.

3. The diverging waveguide of claim 2 , wherein the laser cooling section includes:
a magnetic field coil set including a first magnetic field coil and a second magnetic field coil and configured with a space between the first magnetic field coil and the second magnetic field coil, the magnetic field coil set configured to shift atomic energy levels of the atoms in such a way that any of the atoms that are moving against the cooling laser field from the cooling laser source preferentially absorb photons of light from the cooling laser field so that the atoms will be pushed back toward the center of the magnetic field coil set within the space between the first magnetic field coil and the second magnetic field coil.

4. The diverging waveguide of claim 1 , wherein the diverging waveguide includes:
a second fork section having a second single end, the second fork section also having a third bifurcated end and a fourth bifurcated end opposite the second single end, the second single end of the of the second fork section coupled to the second end of the first section, the second fork section configured with a second angle between the third bifurcated end and the fourth bifurcated end, the second angle determined based on velocities of the portions of a quantum mechanical wavefunction of atoms configured to travel above the waveguide; and
a second loop section having a third loop end and a fourth loop end, the third loop end coupled to the third bifurcated end of the second fork section and the fourth loop end coupled to the fourth bifurcated end of the second fork section.

5. The diverging waveguide of claim 4 , wherein the first section of the diverging waveguide further includes:
wherein the laser cooling section causes at least a second group of the atoms positioned in the potential minimum/well above the surface of the diverging waveguide to move in a second longitudinal direction opposite the first longitudinal direction and towards the second fork section and following the potential minimum/well above the diverging waveguide;
a second atomic state initialization section positioned between the laser cooling section and the second fork section, the second atomic state initialization section configured to initialize atomic states of at least the first group of the atoms moving in the second longitudinal direction following the potential minimum/well above the surface of the diverging waveguide to a second known ground-state configuration; and
a second beam splitter section positioned between the second atomic state initialization section and the second fork section, the second beam splitter section configured to split the a quantum mechanical wavefunction of each atom of the at least the second group of the atoms moving in the second longitudinal direction following the potential minimum/well above the surface of the diverging waveguide into a third portion having a third velocity and a fourth portion having a fourth velocity that is different from the third velocity, wherein the third portion travels into the third bifurcated end of the second fork section of the diverging waveguide and into the third loop end of the second loop section, and wherein the fourth portion travels into the fourth bifurcated end of the second fork section of the diverging waveguide and into the fourth loop end of the second loop section.

6. The diverging waveguide of claim 1 , further comprising:
a mirror positioned at the second end of

Assignees

• Honeywell Int Inc

Inventors

• Compton Robert
• Nelson Karl D
• Fertig Chad

Classifications

• G01C19/721

  Details, e.g. optical or electronical details · CPC title

• G01C19/723 Primary

  Heterodyning fibre optic gyrometers · CPC title

• G01C19/64 Primary

  Gyrometers using the Sagnac effect, i.e. rotation-induced shifts between counter-rotating electromagnetic beams · CPC title

• G01C19/60 Primary

  Electronic or nuclear magnetic resonance gyrometers · CPC title

• H01S3/0915

  by incoherent light · CPC title