Device and method based on atomic beam laser frequency stabilization

Abstract

The invention belongs to the technical field of quantum precision measurement, and particularly discloses a device and method based on atomic beam laser frequency stabilization, and the device comprises a physical system, an optical system and an electrical system. Wherein the physical system is used for generating an atomic beam; the optical system is used for generating laser, controlling the propagation direction of the laser and reacting with the atomic beam to generate fluorescent light; the electrical system is used for receiving, processing and feeding back the fluorescence to a laser of the optical system, so that the frequency of the laser is stabilized on an atomic resonance transition line; the problem that the frequency stability of a laser is affected due to the fact that atomic beam flow fluctuates due to the influence of atomic furnace temperature fluctuation and then is introduced to a detection spectral line through fluorescence detection is solved.

Description

Technical Field

[0001] This invention belongs to the field of quantum precision measurement technology, and particularly relates to a device and method based on atomic beam laser frequency stabilization. Background Technology

[0002] In the field of quantum precision measurement, the interaction between atoms and light fields requires a stable laser frequency source. Free-running lasers, due to fluctuations in current and temperature, experience frequency drift, which cannot meet the frequency stability requirements of quantum precision measurement. Therefore, it is necessary to lock the laser onto a reference source, such as an optical reference cavity or an atomic spectral line. For lasers used in atomic beams, the modulated laser can be directly applied to the atomic beam. By collecting the fluorescence spectral lines of the atoms and using phase-sensitive detection, the error signal of the laser frequency can be obtained, and then fed back to the laser through a servo loop system to obtain a stable laser spectral line. Locking the laser directly onto the atomic beam helps reduce system complexity. However, the atomic beam flux is affected by fluctuations in the atomic furnace temperature, which in turn is introduced into the detection spectral line through fluorescence detection, affecting the laser frequency stability. Therefore, there is an urgent need to propose a laser frequency stabilization method and device to solve the above technical problems. Summary of the Invention

[0003] This invention provides a device and method for stabilizing the frequency of atomic beam lasers, which solves the problem that the fluctuation of atomic beam flux caused by the temperature fluctuation of the atomic furnace causes fluctuations in the atomic beam flux, which in turn is introduced into the detection spectrum through fluorescence detection, affecting the frequency stability of the laser.

[0004] In a first aspect, an apparatus based on atomic beam laser frequency stabilization is provided, the apparatus comprising:

[0005] Physical systems, optical systems, and electrical systems; among them,

[0006] The physical system is used to generate atomic beams;

[0007] The optical system is used to generate laser light and control its propagation direction, and to react with the atomic beam to generate fluorescence;

[0008] The electrical system is used to receive and process fluorescence and feed it back to the laser in the optical system, so that the laser frequency is stabilized on the atomic resonance transition line.

[0009] Secondly, a method for frequency stabilization based on atomic beam laser is provided, the method comprising:

[0010] The physical system generates atomic beams;

[0011] The optical system generates laser light and controls its propagation direction, and reacts with the atomic beam to produce fluorescence;

[0012] The electrical system receives and processes the fluorescence, feeding it back to the laser in the optical system, thus stabilizing the laser frequency on the atomic resonance transition line.

[0013] The present invention provides a device and method for frequency stabilization based on atomic beam laser. The method involves multiple interactions between the laser and the atomic beam, using the laser to select atoms at specific velocities to achieve atomic resonant transitions, and using a differential detector to collect the fluorescence signals of the atoms to obtain an error signal without Doppler background. This error signal is then applied to the laser through a feedback loop to achieve laser frequency locking.

[0014] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0015] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0016] Figure 1 This is a schematic diagram of a device structure based on atomic beam laser frequency stabilization according to an embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this specification clearer, the technical solutions of this specification will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this specification, and not all of them. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this specification.

[0018] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0019] The technical solutions provided in the various embodiments of this specification are described in detail below with reference to the accompanying drawings.

[0020] To achieve frequency locking of a laser, embodiments of the present invention provide a device and method for frequency stabilization based on atomic beam lasers.

[0021] Figure 1 A schematic diagram of a device structure based on atomic beam laser frequency stabilization according to an embodiment of the present invention is shown below. Figure 1 The device includes:

[0022] Physical systems, optical systems, and electrical systems; among them,

[0023] The physical system is used to generate atomic beams;

[0024] The optical system is used to generate laser light and control its propagation direction, and to react with the atomic beam to generate fluorescence;

[0025] The electrical system is used to receive and process fluorescence and feed it back to the laser in the optical system, so that the laser frequency is stabilized on the atomic resonance transition line.

[0026] In one specific implementation,

[0027] The physical system includes: a nuclear furnace and a vacuum system;

[0028] The atomic beam is generated by heating in a vacuum system using an atomic furnace.

[0029] In one specific implementation,

[0030] The optical system includes: a laser, a first reflecting mirror, a first right-angle prism, a first detector, and a second detector; wherein...

[0031] The laser is used to generate laser light;

[0032] The first reflector is used to reflect the laser and act on the atoms, and by adjusting its own direction, the laser and the atoms form a certain angle, and the laser frequency is scanned.

[0033] The first detector is used to collect the fluorescence signal generated by the resonance between atoms and laser light;

[0034] The first right-angle prism is used to reflect the signal after the light field interacts with the atoms and then act on the atomic beam again.

[0035] The second detector is used to collect the fluorescence signal generated by the resonance between the light field and atoms that satisfy the velocity relationship when the angle between the wave vector direction of the light field and the atomic beam is π-θ.

[0036] In one specific implementation,

[0037] Since the frequency sensed by the atom is at a certain angle to the light field generated by the laser, the actual frequency of the interaction between the atom and the light field has a certain frequency shift, namely the Doppler shift. Considering the first-order Doppler shift, the angle between the atomic beam velocity v and the light field direction k is θ, c is the speed of light, ω is the angular frequency of the light field, and ω0 is the transition frequency of the atom when the atomic velocity is 0, satisfying the following equation:

[0038] ω-ω0=ω0v cosθ / c.

[0039] In one specific implementation,

[0040] The electrical system includes a signal processing module and a feedback control module; wherein...

[0041] The signal processing module is used to subtract the fluorescence signals collected by the first detector and the second detector to generate an error signal related to the laser frequency, and transmit it to the feedback control module.

[0042] The feedback control module is used to feed the error signal back to the laser to stabilize the laser frequency.

[0043] The present invention provides a device for frequency stabilization of atomic beam laser. The device is simple, compact in structure, and easy to adjust the optical path. It does not require external modulation of the optical field interacting with atoms, which helps to reduce noise caused by atomic beam fluctuations and reduce the impact of atomic beam fluctuations on the stability of the laser.

[0044] To better understand the present invention, specific embodiments are provided for illustration.

[0045] Example 1:

[0046] Taking calcium atoms as an example, calcium atoms are heated to form an atomic beam. A 423nm laser scans near the transition frequency of cesium atoms. The beam is reflected by a first mirror, and the angle of the mirror is adjusted so that the angle between the atomic beam and the laser, the laser frequency, and the velocity of the atoms in the atomic beam satisfy the following conditions:

[0047] ω - ω0 = ω0v cosθ / c;

[0048] Calcium atoms absorb laser light and transition from the first energy level to the second. Due to the finite lifetime of the second energy level, the atoms spontaneously emit light back to the first energy level, producing fluorescence. This fluorescence is collected by a fluorescence collection system and received by the first detector. The laser then passes through the first right-angle prism. By adjusting the angle between the laser and the atomic beam, when the laser wave vector direction and the atomic beam angle satisfy π-θ, ​​the laser resonates with the atom, absorbing photons and transitioning to the second energy level. This spontaneous emission of fluorescence is then collected by the fluorescence collection system and detected by the second detector, converting it into a fluorescence signal. The signal processing module in the electrical system subtracts the fluorescence signal generated by the first and second detectors to generate an error signal for the laser frequency. This error signal is fed back to the laser via a feedback control module, ensuring that the laser frequency is stabilized along the atomic resonant transition line.

[0049] Based on the same inventive concept, the present invention also provides a method for frequency stabilization of atomic beam lasers, the method comprising:

[0050] The physical system generates atomic beams;

[0051] The optical system generates laser light and controls its propagation direction, and reacts with the atomic beam to produce fluorescence;

[0052] The electrical system receives and processes the fluorescence, feeding it back to the laser in the optical system, thus stabilizing the laser frequency on the atomic resonance transition line.

[0053] In one specific implementation,

[0054] The physical system includes: a nuclear furnace and a vacuum system;

[0055] The atomic beam is generated by heating in a vacuum system using an atomic furnace.

[0056] In one specific implementation,

[0057] The optical system includes: a laser, a first reflecting mirror, a first right-angle prism, a first detector, and a second detector; wherein...

[0058] The laser is used to generate laser light;

[0059] The first reflector is used to reflect the laser and act on the atoms, and by adjusting its own direction, the laser and the atoms form a certain angle, and the laser frequency is scanned.

[0060] The first detector is used to collect the fluorescence signal generated by the resonance between atoms and laser light;

[0061] The first right-angle prism is used to reflect the signal after the light field interacts with the atoms and then act on the atomic beam again.

[0062] The second detector is used to collect the fluorescence signal generated by the resonance between the light field and atoms that satisfy the velocity relationship when the angle between the wave vector direction of the light field and the atomic beam is π-θ.

[0063] In one specific implementation,

[0064] Since the frequency sensed by the atom is at a certain angle to the light field generated by the laser, the actual frequency of the interaction between the atom and the light field has a certain frequency shift, namely the Doppler shift. Considering the first-order Doppler shift, the angle between the atomic beam velocity v and the light field direction k is θ, c is the speed of light, ω is the angular frequency of the light field, and ω0 is the transition frequency of the atom when the atomic velocity is 0, satisfying the following equation:

[0065] ω-ω0=ω0v cosθ / c.

[0066] In one specific implementation,

[0067] The electrical system includes a signal processing module and a feedback control module; wherein...

[0068] The signal processing module is used to subtract the fluorescence signals collected by the first detector and the second detector to generate an error signal related to the laser frequency, and transmit it to the feedback control module.

[0069] The feedback control module is used to feed the error signal back to the laser to stabilize the laser frequency.

[0070] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0071] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A device based on atomic beam laser frequency stabilization, characterized in that, The device includes: Physical systems, optical systems, and electrical systems; among them, The physical system is used to generate atomic beams; The optical system is used to generate laser light and control its propagation direction, and to react with the atomic beam to generate fluorescence; The electrical system is used to receive and process fluorescence and feed it back to the laser in the optical system, so that the laser frequency is stabilized on the atomic resonance transition line.

2. The apparatus according to claim 1, characterized in that, The physical system includes: a nuclear furnace and a vacuum system; The atomic beam is generated by heating in a vacuum system using an atomic furnace.

3. The apparatus according to claim 2, characterized in that, The optical system includes: a laser, a first reflecting mirror, a first right-angle prism, a first detector, and a second detector; wherein... The laser is used to generate laser light; The first reflector is used to reflect the laser and act on the atoms, and by adjusting its own direction, the laser and the atoms form a certain angle, and the laser frequency is scanned. The first detector is used to collect the fluorescence signal generated by the resonance between atoms and the laser; The first right-angle prism is used to reflect the signal after the light field interacts with the atoms and then act on the atomic beam again. The second detector is used to collect the fluorescence signal generated by the resonance between the light field and atoms that satisfy the velocity relationship when the angle between the wave vector direction of the light field and the atomic beam is π-θ.

4. The apparatus according to claim 3, characterized in that, Since the frequency sensed by the atom is at a certain angle to the light field generated by the laser, the actual frequency of the interaction between the atom and the light field has a certain frequency shift, namely the Doppler shift. Considering the first-order Doppler shift, the angle between the atomic beam velocity v and the light field direction k is θ, c is the speed of light, ω is the angular frequency of the light field, and ω0 is the transition frequency of the atom when the atomic velocity is 0, satisfying the following equation: ω-ω0=ω0v cosθ / c.

5. The apparatus according to claim 4, characterized in that, The electrical system includes a signal processing module and a feedback control module; wherein... The signal processing module is used to subtract the fluorescence signals collected by the first detector and the second detector to generate an error signal related to the laser frequency, and transmit it to the feedback control module. The feedback control module is used to feed the error signal back to the laser to stabilize the laser frequency.

6. A method for frequency stabilization based on atomic beam laser, characterized in that, The method, applied to the atomic beam laser frequency stabilization device according to any one of claims 1 to 5, comprises: The physical system generates atomic beams; The optical system generates laser light and controls its propagation direction, and reacts with the atomic beam to produce fluorescence; The electrical system receives and processes the fluorescence, feeding it back to the laser in the optical system, thus stabilizing the laser frequency on the atomic resonance transition line.

7. The method according to claim 6, characterized in that, The physical system includes: a nuclear furnace and a vacuum system; The atomic beam is generated by heating in a vacuum system using an atomic furnace.

8. The method according to claim 7, characterized in that, The optical system includes: a laser, a first reflecting mirror, a first right-angle prism, a first detector, and a second detector; wherein... The laser is used to generate laser light; The first reflector is used to reflect the laser and act on the atoms, and by adjusting its own direction, the laser and the atoms form a certain angle, and the laser frequency is scanned. The first detector is used to collect the fluorescence signal generated by the resonance between atoms and the laser; The first right-angle prism is used to reflect the signal after the light field interacts with the atoms and then act on the atomic beam again. The second detector is used to collect the fluorescence signal generated by the resonance between the light field and atoms that satisfy the velocity relationship when the angle between the wave vector direction of the light field and the atomic beam is π-θ.

9. The method according to claim 8, characterized in that, Since the frequency sensed by the atom is at a certain angle to the light field generated by the laser, the actual frequency of the interaction between the atom and the light field has a certain frequency shift, namely the Doppler shift. Considering the first-order Doppler shift, the angle between the atomic beam velocity v and the light field direction k is θ, c is the speed of light, ω is the angular frequency of the light field, and ω0 is the transition frequency of the atom when the atomic velocity is 0, satisfying the following equation: ω-ω0=ω0v cosθ / c.

10. The method according to claim 9, characterized in that, The electrical system includes a signal processing module and a feedback control module; wherein... The signal processing module is used to subtract the fluorescence signals collected by the first detector and the second detector to generate an error signal related to the laser frequency, and transmit it to the feedback control module. The feedback control module is used to feed the error signal back to the laser to stabilize the laser frequency.

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