Inertial sensor, atomic interferometer, method for adjusting speed and course of atomic beam, and apparatus for adjusting speed and course of atomic beam
An adjuster performs simultaneous irradiation of M laser beams to an atomic beam, where M is a predetermined integer satisfying 3≤M. The course of each of the M laser beams intersects with an approach path of the atomic beam. A component, in a direction perpendicular to the approach path of the atomic beam, of the sum of radiation pressure vectors that the M laser beams respectively have is non-zero. A component, in a direction of the approach path of the atomic beam, of the sum of the radiation pressure vectors that the M laser beams respectively have is negative for atoms having speeds greater than the predetermined speed, and positive for the atoms having speeds smaller than the predetermined speed.
1. An inertial sensor comprising:
a first cold atomic beam generation apparatus to continuously generate a first atomic beam cooled;
a second cold atomic beam generation apparatus to continuously generate a second atomic beam cooled;
a first adjuster to make speeds of first atoms contained in the first atomic beam close to a first predetermined speed and bending a course of the first atomic beam;
a second adjuster to make speeds of second atoms contained in the second atomic beam close to a second predetermined speed and bending a course of the second atomic beam;
a moving standing light wave generator to generate three or more moving standing light waves;
an interference unit to obtain a third atomic beam resulting from interaction between the first atomic beam from the first adjuster and the three or more moving standing light waves, and a fourth atomic beam resulting from interaction between the second atomic beam from the second adjuster and the three or more moving standing light waves;
a first monitor to observe the third atomic beam from the interference unit; and
a second monitor to observe the fourth atomic beam from the interference unit,
wherein the first adjuster comprises a laser beam generator to generate M 1 laser beams satisfying the following conditions A), B) and C), where M 1 is a predetermined integer satisfying 3≤M 1 , and the second adjuster comprises a laser beam generator to generate M 2 laser beams satisfying the following conditions D), E) and F), where M 2 is a predetermined integer satisfying 3≤M 2 :
A) a course of each of the M 1 laser beams intersects with an approach path of the first atomic beam to the first adjuster;
B) a component, in a direction perpendicular to the approach path of the first atomic beam to the first adjuster, of a sum of radiation pressure vectors that the M 1 laser beams respectively have is non-zero;
C) a component, in a direction of the approach path of the first atomic beam to the first adjuster, of the sum of the radiation pressure vectors that the M 1 laser beams respectively have is negative for the first atoms having speeds greater than the first predetermined speed, and positive for the first atoms having speeds smaller than the first predetermined speed;
D) a course of each of the M 2 laser beams intersects with an approach path of the second atomic beam to the second adjuster;
E) a component, in a direction perpendicular to the approach path of the second atomic beam to the second adjuster, of a sum of radiation pressure vectors that the M 2 laser beams respectively have is non-zero; and
F) a component, in a direction of the approach path of the second atomic beam to the second adjuster, of the sum of the radiation pressure vectors that the M 2 laser beams respectively have is negative for the second atoms having speeds greater than the second predetermined speed, and positive for the second atoms having speeds smaller than the second predetermined speed.
2. An atomic interferometer comprising:
a first cold atomic beam generation apparatus to continuously generate a first atomic beam cooled;
a second cold atomic beam generation apparatus to continuously generate a second atomic beam cooled;
a first adjuster to make speeds of first atoms contained in the first atomic beam close to a first predetermined speed and bending a course of the first atomic beam;
a second adjuster to make speeds of second atoms contained in the second atomic beam close to a second predetermined speed and bending a course of the second atomic beam;
a moving standing light wave generator to generate three or more moving standing light waves; and
an interference unit to obtain a third atomic beam resulting from interaction between the first atomic beam from the first adjuster and the three or more moving standing light waves, and a fourth atomic beam resulting from interaction between the second atomic beam from the second adjuster and the three or more moving standing light waves,
wherein the first adjuster comprises a laser beam generator to generate M 1 laser beams satisfying the following conditions A), B) and C), where M 1 is a predetermined integer satisfying 3≤M 1 , and the second adjuster comprises a laser beam generator to generate M 2 laser beams satisfying the following conditions D), E) and F), where M 2 is a predetermined integer satisfying 3≤M 2 :
A) a course of each of the M 1 laser beams intersects with an approach path of the first atomic beam to the first adjuster;
B) a component, in a direction perpendicular to the approach path of the first atomic beam to the first adjuster, of a sum of radiation pressure vectors that the M 1 laser beams respectively have is non-zero;
C) a component, in a direction of the approach path of the first atomic beam to the first adjuster, of the sum of the radiation pressure vectors that the M 1 laser beams respectively have is negative for the first atoms having speeds greater than the first predetermined speed, and positive for the first atoms having speeds smaller than the first predetermined speed;
D) a course of each of the M 2 laser beams intersects with an approach path of the second atomic beam to the second adjuster;
E) a component, in a direction perpendicular to the approach path of the second atomic beam to the second adjuster, of a sum of radiation pressure vectors that the M 2 laser beams respectively have is non-zero; and
F) a component, in a direction of the approach path of the second atomic beam to the second adjuster, of the sum of the radiation pressure vectors that the M 2 laser beams respectively have is negative for the second atoms having speeds greater than the second predetermined speed, and positive for the second atoms having speeds smaller than the second predetermined speed.
3. The atomic interferometer according to claim 2 , wherein the first cold atomic beam generation apparatus comprises:
a first atom source;
a first cold atomic beam generator to generate, by using a first pushing laser beam, the first atomic beam from atoms trapped in space, the atoms being from the first atom source; and
a first atomic beam deflector that the first atomic beam from the first cold atomic beam generator enters, and
the first atomic beam deflector comprises a two-dimensional magneto-optical trapping mechanism or a moving molasses mechanism,
a course of the first atomic beam from the first cold atomic beam generator matches a course of the first pushing laser beam,
in a case that the first atomic beam deflector comprises the two-dimensional magneto-optical trapping mechanism, a zero magnetic field line of a quadrupole magnetic field in the two-dimensional magneto-optical trapping mechanism intersects with the course of the first atomic beam from the first cold atomic beam generator, and
in a case that the first atomic beam deflector comprises the moving molasses mechanism, a course of a standing light wave in the moving molasses mechanism intersects with the course of the first atomic beam from the first cold atomic beam generator.
4. The atomic interferometer according to claim 2 , wherein the second cold atomic beam generation apparatus comprises:
a second atom source;
a second cold atomic beam generator to generate, by using a second pushing laser beam, the second atomic beam from atoms trapped in space, the atoms being from the second atom source; and
a second atomic beam deflector that the second atomic beam from the second cold atomic beam generator enters, and
the second atomic beam deflector comprises a two-dimensional magneto-optical trapping mechanism or a moving molasses mechanism,
a course of the second atomic beam from the second cold atomic beam generator matches a course of the second pushing laser beam,
in a case that the second atomic beam deflector comprises the two-dimensional magneto-optical trapping mechanism, a zero magnetic field line of a quadrupole magnetic field in the two-dimensional magneto-optical trapping mechanism intersects with the course of the second atomic beam from the second cold atomic beam generator, and
in a case that the second atomic beam deflector comprises the moving molasses mechanism, a course of a standing light wave in the moving molasses mechanism intersects with the course of the second atomic beam from the second cold atomic beam generator.
5. The atomic interferometer according to claim 3 , wherein the second cold atomic beam generation apparatus comprises:
a second atom source;
a second cold atomic beam generator to generate, by using a second pushing laser beam, the second atomic beam from atoms trapped in space, the atoms being from the second atom source; and
a second atomic beam deflector that the second atomic beam from the second cold atomic beam generator enters, and
the second atomic beam deflector comprises a two-dimensional magneto-optical trapping mechanism or a moving molasses mechanism,
a course of the second atomic beam from the second cold atomic beam generator matches a course of the second pushing laser beam,
in a case that the second atomic beam deflector comprises the two-dimensional magneto-optical trapping mechanism, a zero magnetic field line of a quadrupole magnetic field in the two-dimensional magneto-optical trapping mechanism intersects with the course of the second atomic beam from the second cold atomic beam generator, and
in a case that the second atomic beam deflector comprises the moving molasses mechanism, a course of a standing light wave in the moving molasses mechanism intersects with the course of the second atomic beam from the second cold atomic beam generator.
6. An apparatus for making speeds of atoms contained in an atomic beam close to a predetermined speed and bending a course of the atomic beam, the apparatus comprising:
a laser beam generator to generate M laser beams satisfying the following conditions A), B) and C), where M is a predetermined integer satisfying 3≤M;
A) a course of each of the M laser beams intersects with an approach path of the atomic beam;
B) a component, in a direction perpendicular to the approach path of the atomic beam, of a sum of radiation pressure vectors that the M laser beams respectively have is non-zero; and
C) a component, in a direction of the approach path of the atomic beam, of the sum of the radiation pressure vectors that the M laser beams respectively have is negative for the atoms having speeds greater than the predetermined speed, and positive for the atoms having speeds smaller than the predetermined speed.
7. The apparatus according to claim 6 , wherein
M=4,
intensities of the four laser beams are equal to one another,
the four laser beams are superposed in one predetermined spatial region through which the atomic beam passes,
wave vectors k 1 , k 2 , k 3 , and k 4 are respectively expressed by
[
Formula
16
]
k
1
=
(
α
+
η
)
e
v
+
β
e
1
2
k
2
=
(
α
+
η
)
e
v
+
β
e
1
2
k
3
=
-
(
α
+
η
)
e
v
+
γ
e
2
2
k
4
=
-
(
α
+
η
)
e
v
+
γ
e
2
2
,
where e v is a unit direction vector in the direction of the approach path of the atomic beam, e 1 and e 2 are arbitrary unit direction vectors in directions each perpendicular to the unit direction vector e v , α>0, β>0, γ>0, and η>0, and
frequency f 1 , f 2 , f 3 and f 4 are respectively expressed by
[Formula 17]
f 1 =f 0 +δ+v d k 1 ·e v
f 2 =f 0 +δ+v d k 2 ·e v
f 3 =f 0 +δ+v d k 3 ·e v
f 4 =f 0 +δ+v d k 4 ·e v
where v d is the predetermined speed, f 1 is a frequency of a laser beam of the wave vector k 1 , f 2 is a frequency of a laser beam of the wave vector k 2 , f 3 is a frequency of a laser beam of the wave vector k 3 , f 4 is a frequency of a laser beam of the wave vector k 4 , and δ<0.
8. The apparatus according to claim 7 , wherein cos (π/4)≤|cos θ 1 |<1, cos (π/4)≤|cos θ 2 |<1, cos (π/4)≤|cos θ 3 |<1 and cos (π/4)≤|cos θ 4 |<1, where θ 1 is an angle between the unit direction vector e v and the wave vector k 1 , θ 2 is an angle between the unit direction vector e v and the wave vector k 2 , θ 3 is an angle between the unit direction vector e v and the wave vector k 3 , and θ 4 is an angle between the unit direction vector e v and the wave vector k 2 .
9. The apparatus according to claim 6 , wherein
M=3,
intensities of the three laser beams are equal to one another,
the three laser beams are superposed in one predetermined spatial region through which the atomic beam passes,
wave vectors k 1 , k 2 , and k 3 are respectively expressed by
[formula 18]
k 1 =−2η n e v −2β e
k 2 =(α+η) e v +βe
k 3 =−(α−η) e v +βe
where e v is a unit direction vector in the direction of the approach path of the atomic beam, e is an arbitrary unit direction vector in a direction perpendicular to the unit direction vector e v , α>0, β>0, γ>0, and η>0, and
frequency f 1 , f 2 , and f 3 are respectively expressed by
[Formula 19]
f 1 =f 0 +δ+v d k 1 ·e v
f 2 =f 0 +δ+v d k 2 ·e v
f 3 =f 0 +δ+v d k 3 ·e v
where v d is the predetermined speed, f 1 is a frequency of a laser beam of the wave vector k 1 , f 2 is a frequency of a laser beam of the wave vector k 2 , and f 3 is a frequency of a laser beam of the wave vector k 3 , and δ<0.
10. The apparatus according to claim 9 , wherein cos (π/4)≤|cos θ 2 |<1, and cos (π/4)≤|cos θ 3 |<1, where θ 2 is an angle between the unit direction vector e v and the wave vector k 2 , and θ 3 is an angle between the unit direction vector e v and the wave vector k 3 .
11. The apparatus according to claim 6 , wherein the atomic beam is a cold atomic beam, the cold atomic beam being composed of atoms whose speeds in a direction perpendicular to a course of the cold atomic beam are suppressed.
12. The apparatus according to claim 7 , wherein the atomic beam is a cold atomic beam, the cold atomic beam being composed of atoms whose speeds in a direction perpendicular to a course of the cold atomic beam are suppressed.
13. The apparatus according to claim 8 , wherein the atomic beam is a cold atomic beam, the cold atomic beam being composed of atoms whose speeds in a direction perpendicular to a course of the cold atomic beam are suppressed.
14. The apparatus according to claim 9 , wherein the atomic beam is a cold atomic beam, the cold atomic beam being composed of atoms whose speeds in a direction perpendicular to a course of the cold atomic beam are suppressed.
15. The apparatus according to claim 10 , wherein the atomic beam is a cold atomic beam, the cold atomic beam being composed of atoms whose speeds in a direction perpendicular to a course of the cold atomic beam are suppressed.