JP6982858B2 - Atom interferometer and its operation method - Google Patents

Description

The present invention relates to an atomic interferometer and a method of operating the same. More specifically, the present invention relates to an atomic interferometer capable of measuring acceleration with high sensitivity and a method of operating the same.

Atom interferometers have been used in a wide range of fields as precision measurement tools since 1991. In its typical operation, the movement of an atom is controlled by rebounding with a photon by sequentially irradiating a group of atoms with a plurality of laser pulses whose pulse width and intensity are controlled. One typical example of such a pulse train is a pulse train containing a π / 2 pulse, a π pulse, and a π / 2 pulse. These pulses realize a series of operations of spatially separating into two states, reversing each state, and interfering between both states, and function as an interferometer.

By performing such an operation on an atom in free space, an acceleration such as a gravitational acceleration g can be observed. In particular, the gravitational acceleration measurement (g measurement) using an atomic interferometer has much higher sensitivity than the previous method (Non-Patent Document 1 and Non-Patent Document 2). Since the sensitivity of g measurement is proportional to the square of the pulse interval, the atomic fountain method is generally used, in which atoms are launched and dropped in free space under the influence of gravity.

It has also been proposed to construct an accelerometer for the atoms in the optical potential by forming the optical potential with a Gaussian beam laser and using it as a guide for the optical potential atoms (Non-Patent Document 3). ..

International Publication No. 2014/0276737

M. Kasevich and S. Chu, "Measurement of the Gravitational Acceleration of an Atom with a Light-Pulse Atom Interferometer," Appl. Phys. B 54, 321-332 (1992), doi: 10.1007 / BF00325375 A, Cronin et al., "Optics and interferometry with atoms and molecules," Reviews of Modern Physics 81 (3), 1051-1129, (2009); doi: 10.1103 / RevModPhys.81.1051 G. D. McDonald et al., "80hk momentum separation with Bloch oscillations in an oscillator guided atom interferometer," PHYSICAL REVIEW A 88, 053620 (2013), doi: 10.1103 / PhysRevA.88.053620 J. McGuirk et al., "Large area light-pulse atom interferometry," Phys. Rev. Lett. 85, 4498 (2000), doi: 10.1103 / PhysRevLett.85.4498

When an attempt is made to use a conventional atomic fountain-type atom interferometer for measuring acceleration, the measurable direction of acceleration is inevitably restricted to the vertical direction. On the other hand, such a constraint is not a problem in the case of utilizing the atomic guide by the optical potential. However, in the case where the optical potential is formed by, for example, a Gaussian beam, the gradient of the light intensity in the optical potential, particularly the gradient in the axial direction of the Gaussian beam becomes a problem. This is because the gradient in the axial direction causes a force, that is, an acceleration, with respect to the atom and affects the atom. In addition, the optical potential of the Gaussian beam also reduces the contrast of the measured atomic interference.

The present invention has an object of solving at least some of the above problems, and contributes to providing a highly sensitive atomic interferometer having no restriction on the direction of acceleration to be measured.

The present inventor has attempted to overcome the light intensity gradient associated with atom interferometers that employ Gaussian beams while enjoying the benefits of using optical potential. Then, he realized that the above problem could be solved by adopting an optical waveguide having a hollow passage.

That is, in one embodiment of the present invention, the hollow has an optical waveguide having a hollow passage extending from the first end to the second end and an atom having an electronic state in an internal state capable of causing a transition between two levels. A laser beam of traveling waves propagating inside the hollow passage and guiding the atoms from either the first end or the second end toward the other, and the atom supply unit for supplying the inside of the passage. A guide laser light source that supplies a guide laser beam, and an optical pulse train of light having the same or substantially the same frequency as the transition frequency between the two levels, at either the first end or the second end. A probe laser light source supplied from to the inside of the hollow passage, wherein the optical pulse train contains π / 2, π, and π / 2 pulses for the two levels of the atom in that order. , Atomic interferometers with probe laser sources are provided.

The present invention can also be implemented as an operating method for an atomic interferometer. That is, in another aspect of the present invention, the inside of the hollow passage extending from the first end to the second end is inside the hollow passage from either the first end or the second end toward the other. Atoms having an internal state of an electronic state capable of causing a transition between two levels and a step of supplying a guide laser beam of a propagating traveling wave are placed inside the hollow passage to which the guide laser beam is supplied. An optical pulse train of light having the same or substantially the same frequency as the transition frequency between the two levels and the supply stage is produced by the guide laser beam from either the first end or the second end. A method of operating an atom interferometer is provided that includes an interferometer operating step that supplies the interior of the hollow passage through which the atom is guided.

In each of the above embodiments of the present invention, preferably, the guide laser beam has a magic frequency at which the optical potential of itself is such that the optical shifts caused by the perturbations to the two levels of the atom are equal to each other. The frequency of the optical pulse forming the optical pulse train is the same as or substantially the same as the transition frequency of the atom receiving the perturbation of the guide laser beam of the magic frequency.

In the above aspect of the present invention, the atom related to the atom interferometer may include not only the atom but also its ion. In addition, the present application may adopt terminology that follows the conventions of the art to which the invention belongs, unless obscured. For electromagnetic waves other than visible light, such as infrared and ultraviolet electromagnetic wave radiation, expressions used in the optical field such as "light", "laser", and "light source" may be used.

In one aspect of the present invention, a highly practical atomic interferometer and a method of operating the same are provided.

FIG. 1 shows the main part of an atomic interferometer that utilizes the optical potential of a Gaussian beam, FIG. 1A is a schematic diagram showing a state in which a guide laser is a Gaussian beam, and FIG. 1B is a schematic diagram showing a state in which a Gaussian beam is used. It is a schematic graph which shows the energy value of the atom of each position guided by the potential. FIG. 2 is an explanatory diagram showing the relationship between the state of an atom and an optical pulse in an atom interferometer including the one of the present embodiment. FIG. 3A is a schematic diagram showing a schematic configuration of an atomic interferometer of the present embodiment in which an optical waveguide having a hollow passage (hollow optical waveguide) is adopted in the embodiment of the present invention, and FIG. 3B is a schematic view of the hollow optical waveguide. FIG. 3C is an enlarged view showing a specific configuration, and FIG. 3C is a schematic diagram listing typical examples of light intensity distribution in a cross section of a hollow passage. FIG. 4 is a schematic explanatory view showing the state of the optical potential (FIG. 4A) and the energy value of the atom (FIG. 4B) in the hollow optical waveguide of the atom interferometer in the embodiment of the present invention. FIG. 5 is a perspective view showing the configuration of an optical waveguide of an atomic interferometer having a three-dimensional operation combined with an atomic interferometer according to the embodiment of the present invention shown in FIG. 3A. FIG. 6A is a layout diagram showing a configuration of an optical waveguide and a configuration of a probe laser light source in a typical configuration of an atom interferometer modified for measuring an acceleration gradient in an embodiment of the present invention. It is a layout diagram which shows the structure of the optical waveguide of the atom interferometer and the structure of the guide laser light source improved for the measurement with the long baseline length in the embodiment of this invention. FIG. 7A is a layout diagram showing a configuration of an optical waveguide and a configuration of a light source in a typical atom interferometer capable of removing fluctuations of a probe laser and measuring acceleration in an embodiment of the present invention, and FIG. 7B is a layout diagram showing the configuration of a light source. It is a layout diagram which shows the structure of the optical waveguide of the typical atom interferometer which can measure the acceleration vector in a two-dimensional plane and the structure of a light source in the embodiment. FIG. 8A is a schematic diagram illustrating the configuration of the optical waveguide of the atom interferometer and the configuration of the optical pulse train by the probe laser light source in the embodiment of the present invention adopting the operation of multiphoton momentum transfer (LMT), and FIG. 8B is a schematic diagram. , It is explanatory drawing which shows the relationship between the change of the state of an atom in the operation, and a pulse.

Hereinafter, embodiments of the atom interferometer according to the present invention will be described with reference to the drawings. Unless otherwise noted in the description throughout the figure, common parts or elements are given common reference numerals. Further, in the figure, each of the elements of each embodiment is not necessarily shown while maintaining the scale ratio of each other.

1. 1. Atom interferometer and its operation 1-1. Operating Principle In order to explain the operating principle of the atomic interferometer of the present embodiment, the operation of the atomic interferometer using a Gaussian beam will be described. FIG. 1 shows the main part of an atom interferometer that utilizes the optical potential of a Gaussian beam. FIG. 1A is a schematic diagram showing a state in which the guide laser is a Gaussian beam, and FIG. 1B is a schematic graph showing the energy values of atoms at each position guided by the optical potential of the Gaussian beam. A force of optical potential acts on an atom, and the force is relatively weak in the z-axis direction and relatively strong in the xy plane. An optical pulse from a probe laser light source (not shown) acts on the atom to change its motion along the z-axis. When acceleration is generated in the z-axis direction, the acceleration is superimposed on the motion of the atom. When the atom is ⁸⁷ Sr, the ground state | 1> is ¹ S ₀ with an electron configuration of ^{5s 2} and the excited state | 2> is ³ P ₀ with an electron configuration of 5s 5p. The state of an atom can be specified by the electronic state, which is the internal state, and the momentum that describes the motion of the atom. Generally, the internal state (electronic state) and the corresponding momentum are combined. It becomes.

In the atom interferometer of the present embodiment, the acceleration acting on the atom is detected in the form of the interference fringes obtained by measuring the occupancy number of the electronic state which is the internal state. FIG. 2 is an explanatory diagram showing the relationship between the state of an atom and an optical pulse in an atom interferometer including the one of the present embodiment. In this application, the ground state | 1> of the electronic state may be described as | S> and the excited state | 2> may be described as | P> for simplification. Further, for an atom indicating the motion of an atom, the wave function of the motion of the atom specified by the momentum is described by | p> specified by the momentum p. The quantum mechanical state of an atom can be expressed by the linear sum of the states specified by the product (outer product) of the electronic state, which is the internal state, and the momentum p. Therefore, it is expressed as the product of either | S> or | P> and | p> specified by the momentum p corresponding to each. The product shall be described as | S, p>, | P, p> and the like. In the present application, the explicit or bold display of the arrow on the symbol character may be omitted for the momentum p and the wave number k of light to be expressed by the three-dimensional vector.

In the atom interferometer of the present embodiment, an optical pulse train having the same frequency as the transition frequency between two levels in the electronic state of an atom is irradiated, and the operation as an interferometer (operation mode) depends on the type of the light pulse train. ) Is changed. Of these, when operating an interferometer corresponding to the Mach-Zender type interferometer in the optical field, an optical pulse train containing three optical pulses called π / 2 pulse, π pulse, and π / 2 pulse in this order is used. The irradiation is performed at intervals of approximately equal time intervals (T).

As shown in FIG. 2, if the electronic state in the initial state is the ground state and the momentum is p, then | S, p>, and the atom is introduced into the Gaussian beam as it is. When the first π / 2 pulse is applied, a pair of atomic states are superposed. One of these pairs is that the electronic state remains in the ground state and the momentum does not change | S, p>, and the other is that the electronic state is in the excited state and the momentum is rebounded from the optical pulse hbar. The momentum of k (where hbar is the quotient of Planck's constant h divided by 2π and k is the wave number of the optical pulse) is received | P, p + hbar · k>. Of the paired atoms, the former is not excited by the optical pulse, the latter is excited and the internal state and momentum are changed, and their superposition gives the quantum mechanical state of the subsequent atoms. Next, when a π pulse is applied, the state of the atom, which was | S, p> and | P, p + hbar · k> up to that point, changes in both the electronic state and the momentum, and then | P, p + hbar · k> and | S, p>, as if the relationship between the electronic state and the momentum increment due to the rebound was interchanged. When | S, p> changes to | P, p + hbar · k>, the electronic state is excited and the momentum of one photon is increased, so that light is absorbed. On the other hand, when | P, p + hbar · k> changes to | S, p>, stimulated emission of light occurs, the electronic state transitions to the ground state, and the momentum for one photon is lost. When the second π / 2 pulse is irradiated as the end of the optical pulse, the | P, p + hbar · k> components generated from each of the separated paired atoms interfere with each other and are similarly generated from each paired atom. The components of | S, p> interfere with each other. The time of π / 2 pulse (first time) to π pulse and the time of π pulse to π / 2 pulse (second time) are almost equal. Note that the π / 2 pulse, π pulse, and π / 2 pulse are oriented in the direction of atomic motion (z-axis direction), and the increase or decrease in momentum occurs only in the z-axis direction. In this interference operation, vibration due to interference is observed between the number of atoms (occupied number) found in | P, p + hbar · k> and the occupied number found in | S, p>. Here, | P, p + hbar · k> and | S, p> are both products (direct products) of the wave function of the internal state of the atom and the wave function of the motion of the atom, but | P> is | p + hbar. -Only with k>, and | S> is associated only with | p>. As a result, the occupancy observation operation is projected only on the internal state, and it is sufficient to determine the occupancy number of the internal state that can be labeled as | S> and | P>. This is practical in that it is not necessary to rely on the slight difference in momentum to detect only the difference in momentum between | p> and | p + hbar · k>. It can be said that it is. That is, this embodiment eliminates the need for an operation for separating atoms after the second π / 2 pulse and long-distance flight of atoms for the separation, simplifying the detection process and reducing the size of the entire device. It can be said that it is practical in terms of conversion.

Interference fringes are measured, for example, by moving the phase offset of one of the two π / 2 pulses with respect to the π pulse and the other π / 2 pulse. The occupied number vibrates once while the phase is changed by 2π. For example _{N P / (N S + N} P) to be calculated, and using the detection pulse (detection pulse), for example by observation of LIF (Laser Induced _{Fluorescence),} can be determined N S, _{N P. Incidentally, N S,} N _P, respectively the internal state | a P> atoms clogging occupation numbers is | S> and. Further, FIG. 1B schematically shows that the transitions directly detected by LIF are | 3> and | 1> (that is, | S>). Atoms divided into two during the period between two π / 2 pulses propagate independently with different momentums, so they travel together in the optical axis direction in the Gaussian beam in the z-axis direction. Even if there are, it will be two arms that can have a path difference. Therefore, the operation of the atom interferometer, such as measuring the acceleration from the interference fringes, is realized.

The ratio of the excited state vibrates by one cycle while the phase offset θ changes from −π to π. The following equation κ (θ) = 1-B + Acos (θ + Δφ) (1) to explain this experimental value
If the values of A, B, and Δφ are determined, the clarity of the interference fringes, that is, the visibility which is an index of the modulation amount, is calculated from the values of A / B, and the phase shift Δφ is also obtained. Here, when the acceleration to be measured and the direction of the probe light are aligned between the phase shift Δφ and the measurement conditions,
Δφ = kaT ² (2)
Relationship is established. However, k is the wave number of the probe light used for the π pulse or the π / 2 pulse, a is the acceleration detected by the atom, and T is the pulse interval of the π / 2 pulse to the π pulse and the π pulse to the π / 2 pulse.

Since the force and acceleration acting on an atom affect the motion of an atom, the optical potential that guides the atom near the optical axis also affects it. In the schematic graph of FIG. 1B, the energy value of the atom at each position guided by the optical potential of the Gaussian beam is shown by 0 as the value in which the electronic state is in the ground state | 1> and is not affected by the optical potential. ing. In the case of adopting a Gaussian beam, the energy value at each position in the z-axis direction becomes a downwardly convex curve reflecting the shape of the optical potential deepening toward the beam waist portion (Non-Patent Document 3). The gradient in the z-axis direction of this curve cannot escape from this influence as long as the Gaussian beam is adopted because the operation of the atom interferometer such as the measurement of the acceleration in the z-axis direction, especially the operation with high sensitivity.

1-2. Hollow Passage Atom Interferometers At least some of the challenges associated with Gaussian beams are overcome by the hollow passage atom interferometers used in this application. In doing so, none of the advantages found in Gaussian beam atom interferometers are lost.

FIG. 3A is a schematic diagram showing a schematic configuration of an atom interferometer 100 of the present embodiment that employs HC-PCF (hollow core photonic crystal fiber) as an example for an optical waveguide (hollow optical waveguide) 120 having a hollow passage. 3B is an enlarged view showing a specific configuration of the hollow optical waveguide 120, and FIG. 3C is a schematic view listing typical examples of light intensity distribution in a cross section of a hollow passage. Further, FIG. 4 is a schematic explanatory view showing the state of the optical potential (FIG. 4A) and the energy value of the atom (FIG. 4B) in the hollow optical waveguide 120 adopted for the atom interferometer 100.

The hollow optical waveguide 120 has a hollow passage 124 extending from the first end 1202 to the second end 1204. The hollow optical waveguide 120 acts such that the hollow passage 124 becomes a waveguide that guides the guide laser beam GL, at least at the wavelength of the guide laser beam GL. For this reason, the hollow optical waveguide 120 preferably includes a cylindrical wall 122 that cylindrically surrounds the hollow passage 124. Specifically, the hollow optical waveguide 120 is an HC-PCF, which is a photonic crystal in which a cylindrical wall 122 guides light propagating through a hollow passage 124. Of the HC-PCFs, there are typically two waveguide principles suitable for this embodiment. One is based on the principle of the optical bandgap for the guide laser beam GL, and the other is the mode of light passing through the hollow passage 124 regardless of the optical bandgap (core mode). The principle is to prohibit coupling between the mode of light propagating through the tubular wall 122 (clad mode) and the mode of propagation (clad mode). In HC-PCF based on the principle of optical bandgap (hereinafter referred to as "PBG waveguide HC-PCF"), the tubular wall 122 becomes a photonic crystal that becomes a photonic bandgap for the leaked light of the wavelength of the guide laser beam GL. It has been made. In the HC-PCF (hereinafter referred to as "IC waveguide HC-PCF") whose principle is the prohibition of the other coupling, the tubular wall 122 has a light mode (core mode) in the hollow passage 124 and a tubular wall 122. It is made into a photonic crystal that prohibits mutual coupling of light modes (clad modes) in the photonic crystal. In both PBG and IC waveguide HC-PCFs, the guide laser beam GL has an intensity peak inside the hollow passage 124, and the atom 10 is guided by the guide laser beam GL inside the hollow passage 124. Can be introduced or passed through. The substantial diameter (mode field diameter) with respect to the guide laser beam GL is, for example, about 40 μm or less. As a result, the hollow optical waveguide 120, which is an optical waveguide, can guide the guide laser beam GL in a single mode or a multi-mode.

The guide laser light source 140 supplies a guide laser beam GL that forms an optical potential in the hollow passage 124. In FIG. 3A, the guide laser beam GL is incident on the hollow passage 124 from the second end 1204 and becomes a traveling wave propagating inside the hollow passage 124 toward the first end 1202. Preferably, the frequency of the guide laser beam GL is the magic frequency ω _M. This magic frequency ω _M is the amount of energy shift that the optical potential of the guide laser beam GL itself brings to the two levels of the atom 10 by perturbation, that is, the frequency at which the optical shifts are equal to each other, and the wavelength of light (wavelength in vacuum). ) Is the frequency of light, which is also called the magic wavelength. For example, for ⁸⁷ Sr, the guide laser beam GL can be set to a magic frequency by setting the wavelength to 813 nm.

The atom supply unit 160 ^{supplies an atom 10 having an electronic state in its internal state, which includes, for example, 87} Sr and can cause a transition between two levels selected from an atom group or the like described later. The atom 10 is supplied to the inside of the hollow passage 124 so as to be incident on the inside of the hollow passage 124, for example, from the first end 1202. If necessary, an additional laser (not shown) is employed to supply the atom 10 to the first end 1202.

The atom interferometer 100 further includes a probe laser light source 180. The probe laser light source 180 transmits an optical pulse train PT by light having the same or almost the same frequency as the transition frequency between two levels of the atom 10 from either the first end or the second end to the inside of the hollow passage. Supply to. In FIG. 3A, the optical pulse train is supplied from the first end 1202 to the hollow passage 124. This optical pulse train contains π / 2, π, and π / 2 pulses for the two levels of atom 10 in that order. These have the same effects as the π / 2, π pulse, and π / 2 pulse shown in the description (FIG. 2) following the Gaussian beam described above. In the probe laser light source 180 of the atom interferometer 100, the distinction between π / 2 pulse and π pulse for the atom 10 is made between two-level atoms and coherent light, as is commonly done in the field of atom interferometer technology. It is expressed by the change of the electronic state due to the rabbi vibration seen in the interaction of. That is, the π pulse means that an atom whose electronic state is in the ground state has a 100% probability of having an excited electronic state by interaction with the pulse, or vice versa. Is an inverted pulse. This inversion corresponds to a change in the phase of the Rabi vibration by π. Similarly, the π / 2 pulse changes the phase of the Rabi vibration by π / 2, for example, the occupancy rate of the ground state and the excited state from the state where the internal state is 100% of either the ground state or the excited state. Is a pulse that causes an interaction such that is equal to 50%.

The sequence of the pulse train PT and its interval are the same as those shown in FIG. That is, the pulse train PT includes π / 2 pulse, π pulse, and π / 2 pulse for 102 levels of atoms in this order, and the pulse intervals (T) are almost uniform. It should be noted that the pulse interval T is usually an order of magnitude longer than the pulse widths of π / 2 pulse, π pulse, and π / 2 pulse, and these pulse widths are discussed in the discussion of whether it can be said that the pulse intervals are almost even. It doesn't matter.

As shown in FIG. 3B, one typical example of the hollow optical waveguide 120 is one in which the guide laser beam GL supplied by the guide laser light source 140 is guided in a single mode so as to have a center of intensity I inside the hollow passage 124. Is. Further, as shown in FIG. 4B, the guide laser beam GL is substantially in the axial direction (z-axis direction) in which the hollow passage 124 extends with respect to the atom 10 at each position inside the hollow passage 124. _{A guide potential UGL} is generated in which an attractive force is applied toward the central axis of the hollow passage 124 in the radial direction r (FIG. 3B), which is a direction orthogonal to the axial direction without applying a force.

In such a hollow passage 124, as shown in FIG. 4B, the energy value at each position in the z-axis direction is a constant value in most sections from the first end 1202 to the second end 1204. This indicates that the guide potential _UGL is not tilted in this direction and produces virtually no axial force. In the Gaussian beam of FIG. 1B, the curve was convex downward, but in the atomic interferometer 100, a guide potential _UGL that does not generate an axial force over a long distance is realized, and the acceleration in the z-axis direction is measured. The optical potential does not overlap with the acceleration or force (including inertial force) to be measured. Further, since the guide potential _UGL exerts an attractive force toward the central axis of the hollow passage 124, the atom 10 is prevented from coming into contact with the inner surface of the tubular wall 122. Since the guide potential _UGL has an action of guiding the atom itself when viewed from the atom 10, it plays a role as a conducting wire of the atom. Thus, atoms 10 guided by the guide potential U _GL, the while being bound to the central axis of the hollow passageway 124 allows movement without friction in the z-axis direction in the radial direction. In particular, if the diameter of the hollow passage 124 is appropriate and the guide laser beam GL itself is in single mode and the guide potential _UGL has sufficient intensity, the guide potential _UGL can guide atoms in single mode. If such an operation is realized, the interference operation becomes ideal because both the guide laser beam GL and the atom are in the single mode. There is a possibility that the visibility of the interference fringes can be increased to 100%. In addition, the Coriolis uncertainty is eliminated and the problem of the curvature of the probe wavefront, which is the problem of atom interferometers, can be avoided. There is no need to consider the uncertainty of the Sagnac effect. These are all properties that are useful for the highly sensitive interference operation of the atom interferometer 100.

In the atom interferometer of the present embodiment, as a typical example different from the single mode shown in FIG. 3B, there is also a hollow optical waveguide 120 having a multi-mode in which _{the guide potential UGL has a plurality of valleys in the hollow passage 124.} Can be adopted. As a typical example of the light intensity distribution in the cross section (xy plane) of the hollow passage 124 shown in FIG. 3C, the light intensity distribution of the atom interferometer of the present embodiment is the single mode shown in FIG. 3B (FIG. 3C). In addition to the LP01), a multimode (for example, LP11, LP12, LP21, LP02 and other higher-order modes) can also be adopted. In the single mode LP01, the light intensity distribution is axisymmetric and has a peak in the center. Therefore, as shown in FIG. 3B, the guide potential _UGL is one valley near the center in the cross section of the hollow passage 124. make. On the other hand, in the multi-mode, the guide potential _UGL has a plurality of valleys in the cross section of the hollow passage 124 because the intensity distribution is generally not axisymmetric and has a plurality of peaks. When viewed in the z-axis direction, the guide potential _UGL is uniform in both the single mode and the multimode. In single mode, the atom is guided along a straight line to the central axis of the hollow passage 124, whereas in multimode, the atom is a plurality of lines parallel to the z-axis (parallel lines). Guided along.

In particular, when the frequency of the guide laser beam GL is selected as the magic frequency (above), the optical shifts brought to the two levels are equal, so that the motion orthogonal to the z-axis in the hollow passage 124 inside the hollow optical waveguide 120 The transition frequency is not affected even if the intensity of the optical potential changes in the radial direction. Therefore, among the atoms 10 guided by the guide laser beam GL, the rate at which the transition frequency shifts and the response to the optical pulse train PT changes is negligibly small. That is, the guide laser beam GL having a magic frequency has an advantage that the tolerance for the change in the optical potential intensity in the radial direction that can remain even in the hollow optical waveguide 120 is increased.

For the measurement of the interference fringes, a detection pulse for detecting the occupancy number of each of the two levels of the atom 10 inside the hollow passage 124 is adopted. ^{For example, if 87} Sr whose internal state is in the ground state | 1> is excited by a resonance laser beam to the dipole transition state described as | 3> in FIG. 4B, the LIF between | 1> and | 3> is excited. The number of occupied | 1> can be determined from the amount of fluorescence in. The occupancy number of | 2> is determined by pre-irradiating a π pulse that inverts the occupancy numbers of | 1> and | 2>, and then similarly by LIF between | 3> and | 1>. Can be obtained by determining. | 1> the occupation numbers _N S of, | 2> the occupation numbers can be calculated _{N P / (N S + N} P) ratio of the excited state by obtaining a when the _{N P} of. In order to obtain the interference fringes, as in the case of FIG. 2, the phase offset of the light of either one of the two π / 2 pulses in the optical pulse train PT is set to the π pulse and the other π / 2. A method of obtaining the ratio while moving with reference to a pulse can be adopted. Similarly, interference fringes can also be obtained by a method of obtaining the ratio while chirping the frequency of light for the optical pulse train PT within a range that can be said to be substantially the same as the transition frequency. With the atom interferometer 100, the operation of the atom interferometer showing greater visibility can be sufficiently expected at the same pulse interval than the interference fringes of FIG. 2A obtained in the case of the Gaussian beam. Further, it can be expected that the visibility does not disappear until the pulse interval T is longer than the relationship between the pulse interval T and the visibility of FIG. 2B obtained in the case of the Gaussian beam. This opens the way for acceleration measurement with higher sensitivity. Moreover, since the uniform guiding potential U _GL over long distances for the hollow waveguide 120 is realized, put off the interaction time. As a result, the pulse interval T in the equation (2) can be made large, and the sensitivity can be increased.

It should be noted that the detection pulse may not necessarily irradiate the inside of the hollow passage 124 through the first end 1202 or the second end 1204 along the z-axis which is the optical axis of the hollow passage 124, or detect only on the z-axis. I don't need it. For example, when the hollow optical wave guide 120 is an IC waveguide HC-PCF, since a band gap of light is not formed in the cylindrical wall 122, the detection pulse is transmitted from the outside of the hollow passage 124 through the cylindrical wall 122. It may be possible to detect light. Therefore, by adopting the IC waveguide HC-PCF, for example, it is detected that the position where the atom exists between the first end 1202 or the second end 1204 in the hollow passage 124 leaks to the outside of the cylindrical wall 122. There is also the advantage that it can be determined by the positional distribution of the pulses.

1-3. Countermeasures against attenuation of the optical waveguide As shown in FIG. 4B, the guide potential _UGL has a constant value between the first end 1202 and the second end 1204, but the reality such as HC-PCF for the hollow optical waveguide 120. If the element of is adopted, it may be accompanied by attenuation when guiding light. In such a case, the light from the guide laser light source 140 may be first incident from the second end 1204 for measurement, and then incident from the first end 1202 for measurement, and so on. It is useful. For this purpose, it is preferable to have an inversion mechanism for incident the light from the guide laser light source 140 from the opposite side of the hollow optical waveguide 120.

1-4. Atomic species In this embodiment, the atomic species for atom 10 is selected from the group consisting of atoms and ions with long-lived metastable states, more specifically ittelbium (Yb), mercury (Hg), and more. It is selected from the group consisting of strontium (Sr), cadmium (Cd), zinc (Zn), magnesium (Mg), and calcium (Ca). Since these atoms can detect the state of the atom by the electronic state, they are suitable for the operation of the interferometer of the present embodiment. Further, among these atomic species, Yb and Hg, which are heavy atoms, have an advantage that the amount of correction due to the attenuation of the hollow optical waveguide 120 with respect to the measured value of acceleration can be reduced.

2. 2. Application Example The atom interferometer of the present embodiment described above can be applied to various uses.
2-1. Multidimensional Accelerometer The atomic interferometer 100 of the present embodiment has a configuration that is sensitive to one-dimensional acceleration, and by combining it, it is possible to obtain more multidimensional acceleration, especially acceleration in a three-dimensional Cartesian coordinate system having x, y, and z axes. It is also possible to configure a three-dimensional atomic interferometer 200 that can measure. FIG. 5 shows the configuration of the optical waveguide of the atomic interferometer 200 having a three-dimensional operation so as to realize the same performance as the atomic interferometer 100 in individual directions by combining the atomic interferometer 100 shown in FIG. 3A. It is a perspective view which shows. For example, it is useful to orient the hollow optical waveguides 120x, 120y, 120z having the same configuration as the HC-PCF adopted for the hollow optical waveguide 120 of the atom interferometer 100 in each direction, for example, as shown in FIG. Is. In addition, a two-dimensional atom interferometer can be configured depending on the application. In these multidimensional atom interferometers, it is not always necessary to have as many common components as the number of dimensions, such as the guide laser light source 140, the atomic supply unit 160, and the probe laser light source 180. The hollow optical waveguide 120 is added according to the required dimension, and the other components are only accompanied by the necessary deformation as appropriate, and a multidimensional and highly sensitive atomic interferometer can be realized by a simple improvement.

2-2. Gradientometer
In addition to the three-dimensional atom interferometer of the present embodiment, it is possible to perform differential operation and perform highly accurate acceleration measurement by using a plurality of atomic groups. For the problem that the sensitivity is deteriorated due to the noise of the probe laser, it is effective to arrange two atom interferometers 100 (FIG. 3) of the present embodiment and perform differential operation. The differential operation is typically realized by two operations, one is a gradient meter that measures the difference in the measured quantity itself, removes common vibration noise, and measures the position gradient of acceleration. .. The other is to devise a way of passing the probe laser instead of the measured quantity (described later in the column of 2-5).

FIG. 6A is a layout diagram showing the configuration of the optical waveguide and the configuration of the probe laser light source 180 in a typical configuration of the atom interferometer 300 modified to measure such a gradient. The hollow optical waveguide 120a, which is the first optical waveguide, and the hollow optical waveguide 120b, which is the second optical waveguide, have hollow passages along a common straight line L in this typical configuration. The hollow optical waveguide 120a and the hollow optical waveguide 120b may be in contact with each other on the close side, or the hollow optical waveguide 120a and the hollow optical waveguide 120b may be a part of one optical waveguide. Atoms 10 are supplied inside the hollow passages of the hollow optical waveguide 120a and the hollow optical waveguide 120b, and the optical pulse PT from the probe laser light source 180 is hollow with the hollow optical waveguide 120b along a common straight line L. It is supplied so as to pass through the optical waveguide 120a. With such a configuration, the noise due to the phase fluctuation of the probe laser is removed by the disturbance of the common mode (in-phase component), and the gradient of the acceleration can be measured with the sensitivity of the quantum limit. Since the acceleration is measured in the straight line L, that is, in the z-axis direction, if the hollow optical waveguide 120a and the hollow optical waveguide 120b are mounted on a common substrate such as one chassis, minute vibration of the ground or the like is transmitted to the chassis. Even if it is transmitted, it becomes an in-phase component, so it can be measured with high sensitivity.

The phase fluctuation of the probe laser becomes an in-phase component in the measurement of the acceleration gradient for the following reasons. As shown in FIG. 6A, for each atom 10 of the hollow optical waveguide 120b and the hollow optical waveguide 120a, the positions are z ₁ and z ₂ , the measured phases are Δφ ₁ , Δφ ₂ , and the accelerations are a ₁ and a. _Let it be 2. The measured phase shift is Δφ = kaT ² (Equation (2)), and there is only the phase fluctuation δφ = ωσ _y T (where σ _y is the Alan deviation of the probe laser light source) of the probe laser light source 180. Uncertainty will be included. However, measuring the acceleration of the gradient .DELTA.a _z,
Δa _z = a ₁ −a ₂ = (Δφ ₂ + δφ- (Δφ ₁ + δφ)) / (kT ² )
Therefore, a value that is not affected by the phase fluctuation δφ is calculated. With such a high-sensitivity gradient meter, it is possible to measure a minute acceleration gradient, for example, measurement of a universal gravitational constant by a mass body 70 arranged so as to surround the hollow optical waveguide 120a and the hollow optical waveguide 120b.

2-3. Tachometer The atomic interferometer of the present embodiment can also be adopted for the operation of detecting the centrifugal force due to rotation. The principle of measuring the centrifugal force due to rotation is the same as that of measuring the gradient of acceleration, and the configuration thereof is also the same as that of the atom interferometer 300 which is the gradient meter described above in relation to FIG. 6A. For example, rotation around an axis parallel to a certain axis included in the xy plane also depends on whether or not the rotation axis passes through a straight line L along which the hollow optical waveguide 120a and the hollow optical waveguide 120b are along, and the rotation axis is hollow optical waveguide 120a. It can be detected regardless of whether it is between the atoms 10 of each of the waveguide 120a and the hollow optical waveguide 120b. In the operation of this rotator, rotation can be detected if the rotation axis of the rotational motion of the entire atom interferometer 100 is not parallel to the z-axis shown in FIG. 6A, and the effect of removing in-phase components is exhibited. And the rotation information can be determined accurately.

2-4. Measurement at long baseline length The atomic interferometer of this embodiment can also be applied to a gravity gradient meter or a gravitational wave interferometer with a long baseline length. In this case as well, measurement is not impossible in principle if two atomic interferometers 100 of the present embodiment are arranged at different positions. In that application, it is preferable to have a configuration in which disturbances such as phase fluctuations that may occur in the probe laser light source 180 are removed in the common mode. FIG. 6B is a layout diagram showing the configuration of the optical waveguide of the atom interferometer 400 and the configuration of the guide laser light source 140 improved for the measurement at the long baseline length. The hollow optical waveguide 120b, which is the first optical waveguide, and the hollow optical waveguide 120d, which is the second optical waveguide, are arranged so that the hollow passage extends in a common direction (z-axis direction). The hollow optical waveguide 120c, which is the first optical waveguide, and the hollow optical waveguide 120d, which is the second optical waveguide, are connected by, for example, an optical fiber 192 and are supplied from a probe laser light source 180 having a common guide laser beam GL. When the atom 10 is supplied to the inside of each of the hollow passages of the hollow optical waveguide 120c and the hollow optical waveguide 120d and the probe laser light source 180 configured in this way is used for measurement, the phase fluctuation of the probe laser light source 180 can be obtained. It can be removed as a common mode disturbance. If the optical fiber 192 is used, Doppler cancellation can be easily performed. Further, by connecting the hollow optical waveguide 120c and the hollow optical waveguide 120d instead of the optical fiber 192 by the relay optical system 194, it is possible to remove disturbances in the common mode such as phase noise of the probe laser light source 180, which is useful. With such a configuration, it is possible to realize a highly sensitive gravitational wave interferometer that operates at a long baseline.

2-5. Elimination of Laser Phase Fluctuation in Acceleration Measurement If the atomic interferometer of this embodiment adopts a differential operation using multiple atomic groups and devises a way to pass the probe laser, the phase fluctuation of the probe laser can be detected in the acceleration measurement. It can also be removed. FIG. 7A is a layout diagram showing a configuration of an optical waveguide and a configuration of a light source in a typical atom interferometer capable of measuring acceleration by removing the phase fluctuation of the probe laser. In the atom interferometer 500, as shown in FIG. 7A, the hollow optical waveguide 120a and the hollow optical waveguide 120b are arranged in parallel with each other. Then, the optical pulse train PT of the probe laser light source 180 is relayed by an arbitrary optical system so that it is antiparallel to each other so that the z-axis is positive in the hollow optical waveguide 120a and negative in the hollow optical waveguide 120b. Pass through. The direction of the guide laser beam GL from the guide laser light source 140 is arbitrary, for example, each is set to be opposite to the direction of the optical pulse train PT. The interference operation is performed by a common optical pulse train PT in which an atom 10 is introduced into each of the hollow optical waveguide 120a and the hollow optical waveguide 120b. In this case, since the optical pulse train PT is antiparallel to each other in the hollow optical waveguide 120a and the hollow optical waveguide 120b and the direction of propagation is reversed, the influence of the phase fluctuation of the probe laser light source 180 is exerted by the measured acceleration. It becomes an in-phase component and is removed.

More specifically, first, as shown in FIG. 7A, for each atom 10 of the hollow optical waveguide 120b and the hollow optical waveguide 120a, the positions are z ₁ , z ₂ , and the measured phases are Δφ ₁ , Δφ ₂ , respectively. Let the acceleration be a ₁ and a ₂ . The measured phase shift is that the common acceleration is measured in each of the hollow optical waveguide 120b and the hollow optical waveguide 120a, and the propagation direction of the optical pulse train PT is z in each of the hollow optical waveguide 120b and the hollow optical waveguide 120a. Eq. (2) is applied to each, noting that the axes are in the plus and minus directions. That is, the measured value is the difference between the two phase shifts in the hollow optical waveguide 120a and the hollow optical waveguide 120b, and when the phase fluctuation δφ of the probe laser light source 180 is included,
Δφ ₂ + δφ- (Δφ ₁ + δφ) = Δφ _{2 − Δφ 1}
= -Ka ₁ T ² + (ka ₂ T ² ) (4)
Will be. Here, if a ₁ is _{almost the same as a 2} and its value is a, then
Δφ _{2 −Δφ 1} = -2kaT ²
Will be. Since the phase fluctuation δφ of the probe laser light source 180 does not appear in this equation, it can be seen that the acceleration a in the z-axis direction can be determined without being influenced by the phase fluctuation.

＝−ｋＴ^２ａ（ｓｉｎθ＋ｃｏｓθ）
＝ｋＴ^２ａ（２）^１／２ｓｉｎ（θ＋π／４） （６）
と表される。ここでｋ_ｘ、ｋ_ｙ（ともにベクトル）は、同じ大きさｋをもちそれぞれ＋ｘ向きおよび−ｙ向きを向く中空光導波路１２０ｘおよび中空光導波路１２０ｙにおける光パルス列ＰＴのためのプローブレーザーの波数ベクトルである。式（６）より、例えばｚ軸回りに原子干渉計６００の向きを走査し方向θを増減させることによってΔφ_２−Δφ_１の最大値を求めると、加速度の方向と最大加速度を決定できる。すなわち、原子干渉計６００はプローブレーザーの位相ゆらぎが同相成分として除去されて高精度な測定を行いつつｘｙ平面内での加速度ベクトルを決定するのに有用である。中空光導波路１２０ｘと中空光導波路１２０ｙとの対のように互いに垂直に組み合わされた原子干渉計（Ｌ字干渉計）は、２次元にとどまらず３次元の加速度の方向やその値を決定するために適用することもできる。図５の原子干渉計２００に例示されるように３次元的に延びるよう向けられた中空導波路から対となるものを選んで原子干渉計６００に準じたＬ字干渉計を構成すれば、３次元の加速度ベクトルを決定することができる。 2-6. Multidimensional Acceleration Measurement In the present embodiment, the removal of the phase fluctuation of the probe laser of the in-phase component by the differential operation described above can also be applied to the one for measuring the multidimensional acceleration. FIG. 7B is a layout diagram showing a configuration of an optical waveguide and a configuration of a light source of a typical atom interferometer 600 capable of measuring an acceleration vector in a two-dimensional plane in the embodiment of the present invention. In the atom interferometer 600, the hollow optical waveguide 120x and the hollow optical waveguide 120y extend parallel to the x-axis and the y-axis of the xyz coordinates fixed to the atom interferometer 600, respectively. The optical pulse train PT from the probe laser light source 180 is incident on the hollow optical waveguide 120x in the positive direction of x, and then passes through the hollow optical waveguide 120y in the negative direction of y. Therefore, the optical pulse train PT propagates at an angle of 90 degrees between the hollow optical waveguide 120x and the hollow optical waveguide 120y. The guide laser beam GL from the guide laser light source 140 may be oriented in any direction, and is passed through the hollow optical waveguide 120y and the hollow optical waveguide 120x in the direction opposite to the optical pulse train PT, for example. Difference between the phase shift [Delta] [phi ₂ and [Delta] [phi ₁ in hollow optical waveguides 120y and hollow optical waveguides 120x each atom 10 is removed as a phase fluctuation in-phase component of the similarly probe laser Equation (4),
^{_{Δφ 2 -Δφ 1 = -ka y T}} 2 - (ka x T 2) (5)
Will be. Here, as shown in FIG. 7B, when the acceleration a acting on the entire atom interferometer 600 is oriented in the direction of the angle θ from the x-axis in the xy plane,

= -KT ² a (sinθ + cosθ)
= KT ² a (2) ^1/2 sin (θ + π / 4) (6)
It is expressed as. Here k _x, k y _(both vector) is the wave vector of the probe laser for optical pulse train PT in hollow optical waveguides 120x and hollow optical waveguides 120y faces the same size k to have each + x direction and -y direction be. From equation (6), for example, by scanning the direction of the atom interferometer 600 around the z-axis and increasing or decreasing the direction θ _{to obtain the maximum value of Δφ 2- Δφ 1} , the direction of acceleration and the maximum acceleration can be determined. That is, the atom interferometer 600 is useful for determining the acceleration vector in the xy plane while performing high-precision measurement by removing the phase fluctuation of the probe laser as an in-phase component. An atom interferometer (L-shaped interferometer) that is vertically combined with each other like a pair of a hollow optical waveguide 120x and a hollow optical waveguide 120y is used to determine the direction and value of three-dimensional acceleration as well as two-dimensional. It can also be applied to. As illustrated in the atomic interferometer 200 of FIG. 5, if a pair is selected from the hollow waveguides oriented three-dimensionally to form an L-shaped interferometer according to the atomic interferometer 600, 3 The dimensional acceleration vector can be determined.

2-7. Multiphoton momentum transfer (LMT) operation In the atom interferometer of the present embodiment described so far, the interference operation separates the atoms corresponding to the arms of the interferometer in the optical pulse from the probe laser light source. It relied on the difference in momentum for one photon. In order to realize a larger momentum difference, it is useful to adopt a method of LMT (large momentum transfer) (Non-Patent Document 4). FIG. 8A is a schematic diagram illustrating the configuration of the optical waveguide of the atom interferometer 700 improved for the operation of the LMT and the configuration of the optical pulse train by the probe laser light source, and FIG. 8B is a schematic diagram illustrating the change in the state of atoms in the operation. It is explanatory drawing which shows. In the atom interferometer 700, the optical pulse train contains π / 2 pulses, multiple π pulses, and π / 2 pulses for the two levels of atom 10 in that order. In FIGS. 8A and 8B, one π / 2 pulse is drawn and up to three π pulses are drawn. At this time, each optical pulse included in the optical pulse train is supplied so as to propagate in the hollow passage 124 in a direction in which at least some of them alternate in the order of forming the optical pulse train. In this case, as shown in FIG. 8B, the momentum of the photon is added to only one atom each time the π pulse is irradiated, so that the momentum modulation amount can be increased and the sensitivity is increased. be able to. In the operation of this LMT, between the phase shift and the measurement condition, instead of the equation (2),
Δφ = NkaT ² (7)
Relationship is established. However, N is the number of photons of the probe light that gives the momentum difference, and the others are the same as in the equation (2). In this way, LMT can increase the sensitivity of acceleration measurement. It should be noted that such an operation realizes the function of separating atoms by using not only one π / 2 pulse but also several subsequent π pulses. Since it is necessary to interfere the two atoms again in order to finally obtain the interference fringes, the atom having a small momentum and advancing with a delay is then advanced by adding the momentum by a plurality of photons by the same method, and the other atom is advanced. Momentum of multiple photons is emitted from the advancing atom to delay it, and the timing of both is aligned and finally they interfere with each other with a π / 2 pulse.

2-8. Optical lattice The inventor of the present application proposes a high-performance optical lattice clock using a hollow passage having a tubular wall in Patent Document 1. This optical lattice clock is a device for a completely different purpose, but uses an element similar to that of the atom interferometer in the present application. Also in the present application, if the guide laser beam is incident on the hollow passage 124 from both sides of the hollow optical waveguide 120, an optical lattice can be formed inside the hollow passage 124. The optical lattice thus formed can be used to control the velocity of the atom 10, and the traveling wave guide described in the present embodiment can be guided by simply stopping one of the guide laser beams from that state. It can be returned to the laser beam. Therefore, in the atom interferometer of the present embodiment including the atom interferometer 100, the frequencies of the guide laser beam and the additional laser beam are shifted from each other, so that the optical lattice is extended in the direction extending through the hollow passage. It is useful to be able to move inside a hollow passage in a certain axial direction. Specifically, if such an optical lattice is used, the operation of introducing the atom 10 into the hollow passage 124 or the control of the initial state of the atom 10 can be easily performed.

The embodiment of the present invention has been specifically described above. The above-described embodiments, modifications and examples are described for the purpose of explaining the invention disclosed in the present application, and the scope of the invention of the present application should be defined based on the description of the scope of claims. It is a thing. Modifications that exist within the scope of the invention, including other combinations of embodiments, are also within the scope of the claims. Also included in the scope of the invention of the present invention are various modifications, combinations, sub-combinations, and alternatives with respect to the components of the above-described embodiments within the technical scope of the present invention or the equivalent thereof. There is.

The present invention can be used as a highly sensitive atom interferometer or as any device that utilizes an atom interferometer.

100, 200, 300, 400, 500, 600, 700 Atom Interferometer 10 Atom 70 Mass Body 120, 120a, 120b, 120c, 120d Hollow Optical Waveguide 1202 1st End 1202 2nd End 122 Cylindrical Wall 124 Hollow Passage 140 Guided laser light source 160 Atom supply unit 180 Probe laser light source 192 Optical fiber 194 Relay optical system PT Optical pulse train GL Guided laser beam

Claims (20)

An optical waveguide with a hollow passage extending from the first end to the second end,
An atom supply unit for supplying an atom having an electronic state that can cause a transition between two levels into the inside of the hollow passage, and an atom supply unit.
A guide laser light source that supplies a guide laser beam, which is a laser beam of a traveling wave that propagates inside the hollow passage toward the other from either the first end or the second end and guides the atom. Here, the guide laser beam generates a guide potential that substantially does not exert a force on the atom in the axial direction, which is the extending direction of the hollow passage, at each position inside the hollow passage. It is a thing
A probe laser light source that supplies an optical pulse train with light having the same or substantially the same frequency as the transition frequency between the two levels from either the first end or the second end into the hollow passage. An atomic interferometer comprising a probe laser light source, wherein the optical pulse train includes π / 2, π, and π / 2 pulses for the two levels of the atom in that order. The guide laser beam has a magic frequency at which the optical potential of itself is the frequency at which the optical shifts caused by perturbation to the two levels of the atom are equal to each other.
The frequency of the optical pulse forming the optical pulse train is the same as or substantially the same as the transition frequency of the atom undergoing the perturbation of the guide laser beam of the magic frequency.
The atomic interferometer according to claim 1. The optical waveguide guides the guide laser beam supplied by the guide laser light source so as to have an intensity center inside the hollow passage.
The guide potential the guide laser beam is generated, at each position within the hollow passage, the atom to the central axis of the hollow passages in the radial direction which is a direction orthogonal to the axis Direction it's also Ru by the action of attraction towards,
The atomic interferometer according to claim 1. The optical waveguide is a hollow core photonic crystal fiber (HC-PCF) having a tubular wall of photonic crystals surrounding the hollow passage.
The atom interferometer according to claim 3. The atom interferometer according to claim 1, further comprising an inversion mechanism that inverts the propagation direction of the guide laser beam from the guide laser light source in the hollow passage. The first aspect of claim 1 is further comprising a detection laser light source that supplies a detection pulse for detecting the occupancy of each of the two levels of the atom inside the hollow passage to the inside of the hollow passage. Atom interferometer. The guide laser light source can simultaneously supply the guide laser beam and an additional laser beam.
The additional laser beam can form a standing wave inside the hollow passage that propagates against the guide laser beam to form an optical lattice.
The optical lattice is capable of moving inside the hollow passage in the axial direction, which is the extending direction of the hollow passage, because the frequencies of the guide laser beam and the additional laser beam are shifted from each other. Is,
The atomic interferometer according to claim 1. The atom is selected from the group consisting of atoms and ions having a long-lived metastable state.
The atomic interferometer according to claim 1. The atom is selected from the group consisting of ytterbium (Yb), mercury (Hg), strontium (Sr), cadmium (Cd), zinc (Zn), magnesium (Mg), and calcium (Ca).
The atom interferometer according to claim 8. In addition to the optical waveguide, that is, the first optical waveguide, a second optical waveguide having hollow passages extending from the first end to the second end is further provided.
The guide laser light source is a traveling wave guide laser propagating inside the hollow passage from either the first end or the second end of the first optical waveguide and the second optical waveguide toward the other. It supplies the beam and
The atom supply unit is for supplying an atom having an electronic state that can cause a transition between two levels into the inside of the hollow passage of the first optical waveguide and the second optical waveguide. can be,
The probe laser light source supplies the optical pulse train from either the first end or the second end of the first optical waveguide and the second optical waveguide into the hollow passage.
The atomic interferometer according to claim 1. The first optical waveguide and the second optical waveguide are arranged non-parallel to each other.
The atom interferometer according to claim 10. In addition to the first optical waveguide and the second optical waveguide, a third optical waveguide having a hollow passage extending from the first end to the second end is further provided.
The guide laser light source supplies a guided laser beam of a traveling wave propagating inside the hollow passage from either one of the first end or the second end of the first to third optical waveguides toward the other. To do
The atom supply unit has an atom having an electronic state in its internal state that can cause a transition between two levels, inside the hollow passage of the first optical waveguide, the second optical waveguide , and the third optical waveguide. Is for supply to
The probe laser light source supplies the optical pulse train from either the first end or the second end of the first to third optical waveguides into the hollow passage.
The atom interferometer according to claim 10. The first optical waveguide and the second optical waveguide are arranged so that their hollow passages are arranged along a common straight line.
The atom supply unit supplies the atom to the inside of the hollow passage of each of the first optical waveguide and the second optical waveguide.
The atom interferometer according to claim 10, wherein the probe laser light source supplies the optical pulse so as to pass through the first optical waveguide and the second optical waveguide along the common straight line. The first optical waveguide and the second optical waveguide are arranged parallel to each other or at an angle.
The atom supply unit supplies the atom to the inside of the hollow passage of each of the first optical waveguide and the second optical waveguide.
Claimed that the optical pulse from the probe laser light source is supplied so as to propagate in the hollow passages of the first optical waveguide and the second optical waveguide so as to be antiparallel to each other or at an angle. 10. The atomic interferometer according to 10. Inside the hollow passage extending from the first end to the second end, a guided laser beam of a traveling wave propagating inside the hollow passage from either one of the first end or the second end toward the other is emitted. The supply stage and
A step of supplying an atom having an electronic state that can cause a transition between two levels into the inside of the hollow passage to which the guide laser beam is supplied, and a step of supplying the atom to the inside of the hollow passage to which the guide laser beam is supplied.
The atom is guided by the guide laser beam from either the first end or the second end of an optical pulse train with light having the same or almost the same frequency as the transition frequency between the two levels. look including the interference operation supplying the inside of the hollow passages are, the guide laser beam, at each position within said hollow passage, with respect to the atom is a direction of extension of the hollow passageway axis A method of operating an atom interferometer that creates a guide potential with virtually no force acting in the direction. After the interference operation step, a step of reversing the propagation direction between the first end and the second end of the guide laser beam in the hollow passage to supply the guide laser beam.
The method of operating an atomic interferometer according to claim 15, further comprising a step of performing the interference operation step again. The guide laser beam has a magic frequency at which the optical potential of itself is the frequency at which the optical shifts caused by perturbation to the two levels of the atom are equal to each other.
The frequency of the optical pulse forming the optical pulse train is the same as or substantially the same as the transition frequency of the atom undergoing the perturbation of the guide laser beam of the magic frequency.
The method of operating the atom interferometer according to claim 15. 15. The 15. 10. How to operate the atom interferometer. The optical pulse train comprises π / 2, π, and π / 2 pulses for the two levels of the atom, in that order.
The method of operating the atom interferometer according to claim 15. The optical pulse train contains π / 2 pulses, a plurality of π pulses, and π / 2 pulses for the two levels of the atom in this order.
The atom interferometer according to claim 15, wherein each optical pulse included in the optical pulse train is supplied so as to propagate through the hollow passage in a direction in which at least some of them alternate in the order of forming the optical pulse train. How it works.

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