A laser generating structure, device and atomic interferometer for an atomic interferometer

Abstract

The present application relates to the technical field of atomic interferometer, and provides a laser generation structure for atomic interferometer, a device and an atomic interferometer.The laser generation structure for atomic interferometer comprises a Raman laser generation component, a wavelength division multiplexing component and a back-pumping light generation component.The first and second ports of the wavelength division multiplexing component are coupled with the main and slave laser output light paths of the Raman laser generation component respectively, and the third port is coupled with the redundant light exit light path of the back-pumping light generation component.The Raman laser generation component generates Raman main and slave lasers by using incident laser.The wavelength division multiplexing component generates Raman light and redundant light by using the Raman main laser and the Raman slave laser, and the back-pumping light generation component obtains back-pumping light by positively frequency shifting the redundant light.The present application can generate back-pumping light and Raman light by using only a single laser source, so that frequency beat phase locking between multiple lasers is not needed, thereby ensuring long-term stable operation of the atomic interferometer.

Description

Technical Field

[0001] This invention relates to the field of atomic interferometer technology, and in particular to a laser generating structure, apparatus and atomic interferometer for use in an atomic interferometer. Background Technology

[0002] Cold atom interferometers utilize laser manipulation of matter waves to achieve precise measurements of gravitational acceleration, gravitational gradient, angular acceleration, etc., and therefore have important applications in fields such as geodesy and inertial navigation.

[0003] To perform operations such as atomic cooling, pumping, loading, quenching, Raman transitions, and detection, the optical system of an atomic interferometer requires laser pulses of different amplitudes, frequencies, and timings to interact with the atomic clusters. These laser pulses are typically generated by multiple lasers and laser amplifiers outputting laser sources of a certain intensity, which are then modulated using frequency-locking and acousto-optic frequency shifters, coupled to optical fibers, and finally input into the vacuum system of the atomic interferometer.

[0004] Laser wavelengths are highly sensitive to temperature and vibration. Therefore, for atomic interferometers to operate stably over long periods, the more lasers used, the greater the susceptibility to external disturbances, leading to a deterioration in operational stability. The impact of lasers becomes particularly significant in environments with numerous interference factors, such as outdoor use or transport. Therefore, implementing an atomic interferometer using a single laser minimizes the instability introduced by the laser.

[0005] Currently, high-precision atomic interferometers all employ two or more light sources. Typically, two lasers are used in beat-locked phase-locking to achieve a pair of Raman beams, thus requiring at least two lasers in the entire interferometer. To achieve cooling and re-pumping functions, two to three additional lasers are needed, increasing the system complexity and cost of the atomic interferometer. Furthermore, to achieve atomic cooling and interference, atomic spectral line locking of individual lasers and beat-locked phase-locking between multiple lasers are required. This means that several lasers must be locked simultaneously; if one laser becomes unlocked, the atomic interferometer cannot function properly. Therefore, atomic interferometers with multiple laser sources are highly sensitive to external vibrations, temperature and humidity changes, which is detrimental to their long-term continuous operation.

[0006] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0007] The technical problem to be solved by the present invention is that atomic interferometers in the prior art usually use multiple laser sources. Since laser sources are sensitive to the external environment, they are prone to frequency drift, which is not conducive to long-term stable operation.

[0008] The present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a laser generation structure for an atomic interferometer, comprising a Raman laser generation component 1, a wavelength division multiplexing component 2, and a pump-back light generation component 3;

[0010] The first port of the wavelength division multiplexing component 2 is coupled to the main laser output optical path of the Raman laser generating component 1; the second port of the wavelength division multiplexing component 2 is coupled to the slave laser output optical path of the Raman laser generating component 1; and the third port of the wavelength division multiplexing component 2 is coupled to the redundant light output optical path of the return pump optical generating component 3.

[0011] The Raman laser generating component 1 is used to generate a Raman master laser and a Raman slave laser using an incident laser; the wavelength division multiplexing component 2 is used to generate Raman light and redundant light using the Raman master laser and the Raman slave laser; the return pump light generating component 3 is used to positively shift the redundant light to obtain the return pump light.

[0012] Preferably, the wavelength division multiplexing component 2 includes a multiplexing component 21 and a polarization adjustment component 22;

[0013] The first port of the wave combiner 21 is coupled to the main laser output optical path of the Raman laser generating component 1, and the second port of the wave combiner 21 is coupled to the slave laser output optical path of the Raman laser generating component 1; the polarization adjustment component 22 is disposed at the output port of the wave combiner 21.

[0014] The beam combiner 21 is used to combine the Raman master laser and the Raman slave laser to obtain an intermediate light;

[0015] The polarization adjustment component 22 is used to adjust the polarization of the intermediate light and to perform wave division on the polarization-adjusted intermediate light to obtain Raman light and redundant light; wherein, the Raman light includes a portion of Raman master laser and a portion of Raman slave laser, and the portion of Raman master laser and the portion of Raman slave laser are in the same polarization state.

[0016] Preferably, the polarization combining component 21 includes a first polarization component 210, a second polarization component 211, and a polarization combining component 212;

[0017] The first port of the polarization combining component 212 is coupled to the Raman main laser output optical path of the Raman laser generating component 1. The first polarization component 210 is disposed at the location of the first port of the polarization combining component 212. The second port of the polarization combining component 212 is coupled to the Raman slave laser output optical path of the Raman laser generating component 1. The second polarization component 211 is disposed at the location of the second port of the polarization combining component 212.

[0018] The first polarization component 210 is used to provide polarization in a first direction for the Raman master laser;

[0019] The second polarization component 211 is used to provide polarization in a second direction for the Raman laser;

[0020] The polarization combining component 212 is used to combine the Raman master laser with the Raman slave laser with the second polarization to obtain the intermediate light.

[0021] Preferably, the polarization adjustment component 22 includes a third polarization component 220 and a polarization wave division component 221;

[0022] The polarization wave splitter component 221 is disposed at the output port of the wave combiner component 21, and the third polarization component 220 is disposed between the polarization wave splitter component 221 and the wave combiner component 21.

[0023] The third polarization component 220 is used to adjust the polarization of the intermediate light so that a portion of the Raman master laser and a portion of the Raman slave laser in the polarization-adjusted intermediate light have the same polarization state.

[0024] The polarization wave division component 221 is used to divide the intermediate light after polarization adjustment, outputting part of the Raman master laser and part of the Raman slave laser with the same polarization state as Raman light, and outputting light other than the Raman light as redundant light.

[0025] Preferably, the return pump light generation component 3 includes a first acousto-optic modulation component 31;

[0026] The first acousto-optic modulation component 31 performs acousto-optic modulation on the redundant light to obtain the return pump light; wherein the return pump light is the positive first-order diffraction light of the redundant light.

[0027] Preferably, the Raman laser generating component 1 includes a second acousto-optic modulation component 11 and a first reflection component 12;

[0028] The first reflective component 12 is disposed on the non-diffractive optical path opposite to the second acousto-optic modulation component 11;

[0029] The incident laser is incident from the side of the second acousto-optic modulation component 11. The second acousto-optic modulation component 11 is used to perform acousto-optic modulation on the incident laser to obtain a Raman follower laser emitted from the diffraction path on the opposite side of the second acousto-optic modulation component 11, and a zero-order light emitted from the non-diffraction path on the opposite side of the second acousto-optic modulation component 11; wherein, the Raman follower laser is the positive first-order diffracted light of the incident laser;

[0030] The first reflective component 12 is used to reflect the zeroth-order light so that the zeroth-order light is incident from the opposite side of the second acousto-optic modulation component 11. The second acousto-optic modulation component 11 is also used to perform acousto-optic modulation on the zeroth-order light to obtain a Raman master laser emitted from the diffraction path on the side of the second acousto-optic modulation component 11. The Raman master laser is the negative first-order diffracted light of the zeroth-order light.

[0031] Preferably, the Raman laser generating component 1 further includes a second reflection component 13, a third reflection component 14, and a fourth reflection component 15;

[0032] The second reflective component 13 is disposed on the diffraction optical path on the same side of the second acousto-optic modulation component 11, the third reflective component 14 is disposed on the diffraction optical path on the opposite side of the second acousto-optic modulation component 11, and the fourth reflective component 15 is optically coupled to the third reflective component 14.

[0033] The second reflection component 13 is used to reflect the Raman master laser to the first port of the wavelength division multiplexing component 2, the third reflection component 14 is used to reflect the Raman laser from the laser to the fourth reflection component 15, and the fourth reflection component 15 is used to reflect the Raman laser from the laser to the second port of the wavelength division multiplexing component 2. Preferably, the Raman laser generating component 1 further includes a first collimation component 16 and a second collimation component 17;

[0034] The first collimation component 16 is disposed on the same side as the second acousto-optic modulation component 11 and is used to focus the incident laser and the Raman master laser. The second collimation component 17 is disposed on the opposite side of the second acousto-optic modulation component 11 and is used to focus the zero-order light and the Raman slave laser.

[0035] Preferably, it also includes a fifth reflection component 4, which is disposed at the third port of the wavelength division multiplexing component 2;

[0036] The fifth reflection component 4 is used to reflect the redundant light to the return pump light generation component 3.

[0037] Preferably, it also includes a third collimation component 5 and a fourth collimation component 6;

[0038] The third collimation component 5 is disposed on the same side of the return pump light generation component 3 and is used to focus the redundant light;

[0039] The fourth collimation component 6 is disposed on the opposite side of the return pump light generation component 3 and is used to focus the return pump light.

[0040] In a second aspect, the present invention also provides a laser generating device for an atomic interferometer, comprising a Raman pumping unit 7, a single laser 8, an amplifier 9, a frequency locking unit 10, a cooling unit 18, and a beam splitting switch unit 19; wherein, the Raman pumping unit 7 is the laser generating structure for an atomic interferometer described in the first aspect;

[0041] The frequency locking unit 10 is used to lock the frequency of the single laser 8;

[0042] The single laser 8 is used to generate an initial laser, and the amplifier 9 is used to amplify the initial laser to obtain an amplified laser;

[0043] The cooling unit 18 is used to generate cooling light using a portion of the amplified laser;

[0044] Another portion of the amplified laser is transmitted as the incident laser to the Raman pumping unit 7, which is used to generate Raman light and pumping light using the incident laser.

[0045] The beam splitting unit 19 is used to perform beam combining and splitting processing on the pump back light, cooling light and Raman light to obtain the light required to realize the atomic interferometer.

[0046] Thirdly, the present invention also provides an atomic interferometer, including the laser generating structure for an atomic interferometer as described in the first aspect, or including the laser generating device for an atomic interferometer as described in the second aspect.

[0047] Compared with existing technologies, the advantages of this invention are as follows: By utilizing the redundant light lost during the combination of the Raman master laser and the Raman slave laser, this invention generates pump-back light using the redundant light. This fully utilizes the redundant laser power and eliminates the need for an additional frequency-stabilized laser to achieve pump-back light, reducing costs. Furthermore, it eliminates the need for a dedicated laser for pump-back light, thus reducing the number of lasers required. Further, the Raman laser assembly uses a single laser beam (i.e., the incident laser) to generate the Raman master laser and the Raman slave laser, requiring only one laser. Therefore, a single laser source is sufficient to generate both pump-back light and Raman light, eliminating the need for beat-locking between multiple lasers and ensuring the long-term stable operation of the atomic interferometer. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a schematic diagram of the architecture of a laser generation structure for an atomic interferometer provided in an embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram of another laser generation structure for an atomic interferometer provided in an embodiment of the present invention;

[0051] Figure 3 This is a schematic diagram of the wavelength division multiplexing component in a laser generation structure for an atomic interferometer provided in an embodiment of the present invention;

[0052] Figure 4 This is a schematic diagram of the Raman laser generation component in a laser generation structure for an atomic interferometer provided in an embodiment of the present invention;

[0053] Figure 5 This is a schematic diagram of a laser generation structure for an atomic interferometer provided in an embodiment of the present invention;

[0054] Figure 6 This is a schematic diagram of another laser generation structure for an atomic interferometer provided in an embodiment of the present invention;

[0055] Figure 7 This is a schematic diagram of the architecture of a laser generating device for an atomic interferometer provided in an embodiment of the present invention;

[0056] Figure 8 This is a schematic diagram of another laser generating device for an atomic interferometer provided in an embodiment of the present invention;

[0057] Figure 9 This is a schematic diagram of the energy level distribution of each laser in a laser generation structure for an atomic interferometer provided in an embodiment of the present invention.

[0058] In all the accompanying drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0059] 1. Raman laser generation component; 11. Second acousto-optic modulation component; 12. First reflection component; 13. Second reflection component; 14. Third reflection component; 15. Fourth reflection component; 16. First collimation component; 17. Second collimation component; 2. Wavelength division multiplexing component; 21. Wavelength combining component; 210. First polarization component; 211. Second polarization component; 212. Polarization combining component; 22. Polarization adjustment component; 220. Third polarization component; 221. Polarization wave splitting component; 3. Pump back light generation component; 31. First acousto-optic modulation component; 4. Fifth reflection component; 5. Third collimation component; 6. Fourth collimation component; 7. Raman pump back unit; 8. Laser; 9. Amplifier; 10. Frequency locking unit; 18. Cooling unit; 19. Beam splitting switch unit. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0061] In the description of this invention, the terms "inner", "outer", "longitudinal", "lateral", "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and do not require that this invention must be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0062] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0063] In this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium. Furthermore, the term "coupled" can refer to an electrical connection method for achieving signal transmission.

[0064] Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0065] Example 1:

[0066] Existing atomic interferometers typically use multiple laser sources. However, because laser sources are highly sensitive to the external environment and prone to frequency drift, they are not conducive to long-term stable operation. To address this issue, Embodiment 1 of this invention provides a laser generation structure for an atomic interferometer, such as... Figure 1 As shown, it includes a Raman laser generating component 1, a wavelength division multiplexing component 2, and a return pump light generating component 3.

[0067] The first port of the wavelength division multiplexing component 2 is coupled to the main laser output optical path of the Raman laser generating component 1, the second port of the wavelength division multiplexing component 2 is coupled to the slave laser output optical path of the Raman laser generating component 1, and the third port of the wavelength division multiplexing component 2 is coupled to the redundant light output optical path of the return pump light generating component 3.

[0068] The Raman laser generating component 1 is used to generate a Raman master laser and a Raman slave laser using an incident laser; the wavelength division multiplexing component 2 is used to generate Raman light and redundant light using the Raman master laser and the Raman slave laser; the return pump light generating component 3 is used to positively shift the redundant light to obtain the return pump light.

[0069] The incident laser is generated by a single laser, and the Raman light is output from the fourth port of the wavelength division multiplexing component 2. Since the atoms used in existing atomic interferometers are mainly Rb-85, Rb-87, and Cs-133, the frequency difference between the Raman light and the return pump light is small, approximately on the order of several hundred MHz, based on their atomic energy level structures. For example, the frequencies of the Raman laser and the return pump light are approximately 1 GHz. Due to this small frequency difference, it has been found that the return pump light can be obtained by frequency shifting the Raman laser.

[0070] The redundant light is actually the portion lost by the wavelength division multiplexing component 2 during the wave combining process to obtain Raman light, which includes Raman slave laser. In this embodiment, by utilizing this lost portion, i.e., using the redundant light to generate pump back light, the redundant laser power is fully utilized, and there is no need to add a frequency-stabilized laser to achieve pump back light, thus reducing costs. Furthermore, there is no need to set up a laser specifically for pump back light, thereby reducing the number of lasers used. Moreover, the Raman laser component uses a single laser beam (i.e., the incident laser) to generate Raman master laser and Raman slave laser, requiring only one laser. Therefore, this embodiment only needs a single laser source to achieve the generation of pump back light and Raman light, thus eliminating the need for beat-locking between multiple lasers to ensure the long-term stable operation of the atomic interferometer.

[0071] The return-pump light generating component 3 can be a photoelectric modulator, but the modulation sidebands of the photoelectric modulator cannot be spatially separated, resulting in impure frequency components in the generated return-pump light. To solve this problem, this embodiment provides a preferred implementation: the return-pump light generating component 3 includes a first acousto-optic modulation component 31; the first acousto-optic modulation component 31 performs acousto-optic modulation on the redundant light to obtain the return-pump light; wherein the return-pump light is the positive first-order diffracted light of the redundant light.

[0072] In practical application scenarios, such as Figure 2As shown, the wavelength division multiplexing (WDM) component 2 includes a multiplexing component 21 and a polarization adjustment component 22. The first port of the multiplexing component 21 is coupled to the Raman master laser output optical path of the Raman laser generating component 1, and the second port of the multiplexing component 21 is coupled to the Raman slave laser output optical path of the Raman laser generating component 1. The polarization adjustment component 22 is positioned at the output port of the multiplexing component 21. The multiplexing component 21 is used to multiplex the Raman master laser and the Raman slave laser to obtain an intermediate light. The polarization adjustment component 22 is used to adjust the polarization of the intermediate light and to perform wavelength division on the polarization-adjusted intermediate light to obtain Raman light and redundant light. The Raman light contains a portion of the Raman master laser and a portion of the Raman slave laser, and the portion of the Raman master laser and the portion of the Raman slave laser are in the same polarization state.

[0073] In alternative implementations, such as Figure 3 As shown, the polarization combining component 21 includes a first polarization component 210, a second polarization component 211, and a polarization combining component 212; the first port of the polarization combining component 212 is coupled to the main laser output optical path of the Raman laser generating component 1, the first polarization component 210 is disposed at the location of the first port of the polarization combining component 212, the second port of the polarization combining component 212 is coupled to the slave laser output optical path of the Raman laser generating component 1, and the second polarization component 211 is disposed at the location of the second port of the polarization combining component 212.

[0074] The first polarization component 210 is used to provide polarization in a first direction for the Raman master laser; the second polarization component 211 is used to provide polarization in a second direction for the Raman slave laser; the polarization combining component 212 is used to combine the Raman master laser polarized in the first direction with the Raman slave laser polarized in the second direction to obtain the intermediate light.

[0075] The polarization adjustment component 22 includes a third polarization initiation component 220 and a polarization wave splitter component 221. The polarization wave splitter component 221 is located at the output port of the wave combiner component 21, and the third polarization initiation component 220 is located between the polarization wave splitter component 221 and the wave combiner component 21. The third polarization initiation component 220 is used to adjust the polarization of the intermediate light so that a portion of the Raman master laser and a portion of the Raman slave laser in the polarization-adjusted intermediate light have the same polarization state. The polarization wave splitter component 221 is used to split the polarization-adjusted intermediate light, outputting the portion of the Raman master laser and the portion of the Raman slave laser with the same polarization state as Raman light, and outputting light other than the Raman light as redundant light.

[0076] In practical applications, the first polarizing component 210, the second polarizing component 211, and the third polarizing component 220 are all adjustable waveplates, and the polarization combining component 212 and the polarization splitting component 221 are polarization beam splitters. The first direction is the reflection polarization direction of the polarization combining component 212, and the second direction is the transmission polarization direction of the polarization combining component 212.

[0077] The Raman master laser passes through the first polarizer 210, which converts it entirely into a reflected polarized laser beam that exits from the left end of the polarization combiner 212. The Raman slave laser passes through the second polarizer 211, which converts it entirely into a transmitted polarized laser beam that exits from the left end of the polarization combiner 212, thus achieving beam combining to obtain the intermediate light, i.e., the light obtained after combining the two laser beams. Since the two lasers are in different polarization states after being combined by the polarization combiner 212, a third polarizer 220 and a polarization splitter 221 are needed to unify the polarization states of the two lasers to facilitate subsequent operations such as intensity ratio monitoring, fiber coupling, and laser amplification. By adjusting the third polarizer 220, the Raman master laser and the slave laser can be adjusted to the same polarization state. However, because the polarization states of the two lights before the third polarizer 220 are perpendicular, it is impossible to simultaneously and completely convert both lights to the same polarization state, thus generating redundant light. If the Raman master laser and the Raman slave laser have equal intensity and all optical components are ideal, then when the third polarization component 220 is arbitrarily adjusted, the ratio of the intensity of the redundant light output from the lower part of the polarization wave division component 221 to the intensity of the Raman light output from the left end of the polarization wave division component 221 should be 1:1.

[0078] The Raman light includes a Raman master laser and a Raman slave laser, and the redundant light includes another Raman master laser and another Raman slave laser. However, when using the redundant light to generate the return pump light, since the energy level of the Raman slave laser is relatively close to the energy level of the desired return pump light, the Raman slave laser in the redundant light is used to generate the return pump light. Although the Raman master laser also participates in the positive frequency shifting process, since the energy level of the Raman master laser is far from the energy level of the desired return pump light, it does not affect the overall energy level of the return pump light.

[0079] In a preferred embodiment, the Raman laser generating component 1 is also implemented using an acousto-optic modulation component, such as... Figure 4As shown, the Raman laser generating component 1 includes a second acousto-optic modulation component 11 and a first reflection component 12; the first reflection component 12 is disposed on the non-diffraction optical path opposite to the second acousto-optic modulation component 11; the incident laser is incident from the side of the second acousto-optic modulation component 11, and the second acousto-optic modulation component 11 is used to perform acousto-optic modulation on the incident laser to obtain a Raman follower laser emitted from the diffraction optical path opposite to the second acousto-optic modulation component 11, and a zero-order light emitted from the non-diffraction optical path opposite to the second acousto-optic modulation component 11; wherein, the Raman follower laser is the positive first-order diffracted light of the incident laser.

[0080] The first reflecting component 12 reflects the zero-order light, causing it to enter from the opposite side of the second acousto-optic modulation component 11. The second acousto-optic modulation component 11 further modulates the zero-order light acousto-optically to obtain a Raman master laser emitted from the diffraction path on its own side; wherein the Raman master laser is the negative first-order diffracted light of the zero-order light. The "own side" of the second acousto-optic modulation component 11 refers to the side where the incident laser is incident, and the "opposite side" refers to the side opposite to the incident laser side. In practical applications, the second acousto-optic modulation component 11 is an acousto-optic modulator, and the first reflecting component 12 is a reflector.

[0081] The process by which the second acousto-optic modulation component 11 modulates the incident laser is actually the process of generating positive first-order diffracted light and zero-order light from the incident laser. The positive first-order diffracted light exits from the opposite diffraction path, becoming Raman laser light, while the zero-order light exits from the opposite non-diffraction path and is transmitted to the first reflection component 12. The first reflection component 12 causes the zero-order light to be transmitted in the opposite direction along the opposite non-diffraction path to the second acousto-optic modulation component 11. The second acousto-optic modulation component 11 modulates the zero-order light... The acousto-optic modulation process is actually the process of obtaining negative first-order diffracted light and non-diffracted light from the zero-order light. The negative first-order diffracted light is emitted from the diffraction path on this side. When the incident laser propagates from this side to the diffraction path on the opposite side, the direction of light deflection is the same as the direction of the current applied by the second acousto-optic modulation component 11, thus generating positive first-order diffracted light. When the zero-order light propagates from the opposite side to the diffraction path on this side, the direction of light deflection is opposite to the direction of the current applied by the second acousto-optic modulation component 11, thus generating negative first-order diffracted light.

[0082] In alternative implementations, such as Figure 5As shown, the Raman laser generating component 1 further includes a second reflection component 13, a third reflection component 14, and a fourth reflection component 15; the second reflection component 13 is disposed on the diffraction optical path on the same side of the second acousto-optic modulation component 11, the third reflection component 14 is disposed on the diffraction optical path on the opposite side of the second acousto-optic modulation component 11, and the fourth reflection component 15 is optically coupled to the third reflection component 14.

[0083] The second reflecting component 13 is used to reflect the Raman master laser to the first port of the wavelength division multiplexing component 2, the third reflecting component 14 is used to reflect the Raman laser from the laser to the fourth reflecting component 15, and the fourth reflecting component 15 is used to reflect the Raman laser from the laser to the second port of the wavelength division multiplexing component 2. In practical applications, the second reflecting component 13, the third reflecting component 14, and the fourth reflecting component 15 can all be mirrors.

[0084] In practical use, such as Figure 6 As shown, the Raman laser generating component 1 further includes a first collimation component 16 and a second collimation component 17; the first collimation component 16 is disposed on the same side as the second acousto-optic modulation component 11 and is used to focus the incident laser and the Raman master laser; the second collimation component 17 is disposed on the opposite side of the second acousto-optic modulation component 11 and is used to focus the zero-order light and the Raman slave laser.

[0085] The laser generation structure for the atomic interferometer further includes a third collimating component 5 and a fourth collimating component 6; the third collimating component 5 is disposed on the same side as the return pump light generation component 3 and is used to focus the redundant light; the fourth collimating component 6 is disposed on the opposite side of the return pump light generation component 3 and is used to focus the return pump light. The first collimating component 16, the second collimating component 17, the third collimating component 5, and the fourth collimating component 6 can all be lenses.

[0086] Example 2:

[0087] Based on the laser generating structure for an atomic interferometer described in Embodiment 1, this embodiment also provides a laser generating device for an atomic interferometer, such as... Figure 7 As shown, it includes a Raman pumping unit 7, a single laser 8, an amplifier 9, a frequency locking unit 10, a cooling unit 18, and a beam splitting switch unit 19; wherein, the Raman pumping unit 7 is the laser generation structure for an atomic interferometer described in Example 1.

[0088] The frequency-locking unit 10 is used to lock the frequency of the single laser 8; the single laser 8 is used to generate an initial laser, and the amplifier 9 is used to amplify the initial laser to obtain an amplified laser; the cooling unit 18 is used to generate cooling light using a portion of the amplified laser; another portion of the amplified laser is transmitted as an incident laser to the Raman return pump unit 7, and the Raman return pump unit 7 is used to generate Raman light and return pump light using the incident laser; the beam splitting unit 19 is used to perform beam combining and splitting processing on the return pump light, cooling light, and Raman light to obtain the light required to realize the atomic interferometer.

[0089] The laser 8 first splits one beam of light into a frequency-locking unit 10 for frequency locking, and the other beam of light is amplified by an amplifier 9 for laser power amplification. Then, it passes through a cooling unit 18 to generate the main cooling laser, a Raman return pump unit 7 to generate return pump light and phase-coherent Raman light, and finally passes through a beam splitter unit 19 to couple the output fiber into the vacuum system.

[0090] The laser 8 can be an independent laser 8, or a laser output from a laser 8 amplified by a frequency doubling crystal. The laser source splits into two beams. One beam passes through a frequency locking unit 10, which locks the frequency of the laser 8 according to the beam. The other beam passes through the amplifier 9 and is modulated to generate the required functional lasers.

[0091] The laser light emitted directly from a laser source is typically around tens of milliwatts, which is insufficient to meet the optical power requirements of a high-precision atomic interferometer. The amplifier 9 amplifies the laser source to hundreds of milliwatts or even watts, and then splits and modulates the light to generate functional laser beams.

[0092] One beam of the amplified laser enters the cooling unit 18, which uses an acousto-optic modulator to frequency-shift the laser and generate cooling light. For a free-fall atomic interferometer testing mass, the cooling light requires at least one acousto-optic modulator; for an atomic interferometer that requires atom ejection, the laser entering the cooling unit 18 needs to be split and passed through at least three acousto-optic modulators to generate light with three output frequencies. In a vacuum system, these three frequencies of light are positioned at a certain spatial angle, which can change the direction of atomic motion. In addition, for push beams, probe beams, quench beams, etc., which are very close to the frequency of the cooling light, they can be obtained by using the same acousto-optic modulator as the cooling light and then splitting the beam for time-division multiplexing, or by splitting the amplified laser beam and then adding an acousto-optic modulator.

[0093] Another beam from the amplified laser enters the Raman pumping unit 7 as the incident laser. The Raman light is generated by positive and negative modulation frequency shifting of the acousto-optic modulator, with the frequency difference being the splitting distance of the atomic hyperfine energy level structure. After being combined by the positive and negative frequency-shifted laser beams, it is output as Raman light, and the redundant light from the beam combining process is used to generate pumping light. The Raman pumping unit 7 is the laser generation structure for the atomic interferometer described in Example 1. The specific generation principles of the laser generation structure for the atomic interferometer, as well as the Raman light and pumping light, have been described in detail in Example 1 and will not be repeated here. The acousto-optic modulator in the Raman pumping unit 7 is driven by a combination of an RF signal source and a power amplifier. The phase noise of the Raman light depends on the phase noise of the RF source (i.e., the incident laser). In the low-frequency part, its phase noise is consistent with the phase noise of the RF source. Therefore, the generated Raman light and pumping light have low noise, making it suitable for high-precision atomic interferometers that are most sensitive to low-frequency phase noise. Furthermore, this Raman light generation method does not require phase-locked loops or proportional-integral-derivative (PID) feedback for the laser, resulting in low noise and high practicality. Depending on the actual optical power requirements, after combining the Raman master laser and the Raman slave laser to obtain Raman light, a laser amplifier can be added to amplify the Raman light to achieve higher power Raman light.

[0094] Currently, the atoms used in atomic interferometers are mainly Rb-85, Rb-87, and Cs-133. Based on their atomic energy level structures, the frequency difference between the cooling light and the pump light in these atomic interferometers is relatively small compared to the frequency difference between the two Raman beams, on the order of hundreds of MHz. The detuning of the Raman master laser relative to the cooling light is about 1 GHz. Therefore, the frequencies of the Raman master laser and the pump light are approximately 1 GHz. The pump light can be obtained by frequency shifting the Raman master laser using an acousto-optic modulator. Since a portion of the Raman master laser is lost during master-slave laser beam combining, this portion is acousto-optically modulated to obtain the pump light. This fully utilizes the redundant laser power and eliminates the need for an additional frequency-stabilized laser, thus reducing costs. Furthermore, the first acousto-optic modulation component 31 has a fast switching function, making rapid normalized detection (on the order of μs) of the atomic interferometer possible.

[0095] This embodiment also provides an atomic interferometer, including the laser generating structure for an atomic interferometer described in Embodiment 2, or including the laser generating device for an atomic interferometer described above. The following uses the atomic interferometer including the laser generating device for an atomic interferometer as an example, combined with specific application scenarios, and employs technical descriptions within those scenarios to illustrate the implementation process of the present invention in relevant scenarios.

[0096] Taking the Rb-85 atomic interferometer as an example, its optical path structure, laser energy level distribution, and generation method are as follows: Figure 6 and Figure 8 As shown, a 780nm semiconductor laser can be used as laser 8, with an output power typically reaching around 100mW. A portion of the initial laser light emitted from laser 8 enters the frequency-locking unit 10 to lock the frequency of laser 8. An acousto-optic modulator can be added to this frequency-locking unit 10, so that the frequency locked by laser 8 is a negative detuning Δf1 (which can be 70MHz) relative to the energy level transition frequency F=3->F'=4 on the D2 line of Rb-85 atoms. Figure 9 As shown), this can be achieved using an acousto-optic modulator (AOM) operating at a frequency of 70MHz. The second beam split from the initial laser is optically amplified to produce a laser with watt-level optical power. The amplified laser is then split, with one beam entering cooling unit 18. Cooling unit 18 uses two acousto-optic modulators operating at different frequencies to sequentially perform positive frequency shifts (Δf1+Δf2) and negative frequency shifts (Δf2+δf and Δf2), respectively, generating cooling light and probe light (also called pusher light or quenching light, etc.). Figure 9 As shown, Δf2 is 160MHz, which can be generated by a two-way frequency shift of the AOM with a center frequency of 80MHz; δf is 12MHz. The acousto-optic modulator that performs the frequency shift first can perform a negative frequency sweep to cool the atoms with polarization gradients.

[0097] The amplified beam of light enters the Raman return pump unit 7, whose main optical path structure is as follows: Figure 6As shown. The incident laser enters the second acousto-optic modulation component 11 for frequency shifting. The second acousto-optic modulation component 11 operates at a frequency around 1.517 GHz. A first collimating component 16 and a second collimating component 17 are added before and after to focus the light spot, enhancing the diffraction efficiency of the AOM. After frequency shifting, the positive first-order diffracted light and the zero-order light of the incident laser are obtained. The positive first-order diffracted light is the Raman slave laser. The zero-order light is reflected by the first reflecting component 12 and then passes through the second acousto-optic modulation component 11 again for negative first-order diffraction, obtaining the Raman master laser. The Raman master laser is reflected by the second reflecting component 13 and reaches the first port of the wavelength division multiplexing component 2. The positive first-order diffracted light after passing through the second collimating component 17 is reflected by the third reflecting component 14 and the fourth reflecting component 15 and reaches the second port of the wavelength division multiplexing component 2. The two beams (i.e., the Raman master laser and the Raman slave laser) are combined at the polarization combining component 212. The first polarizer 210 and the second polarizer 211 are used to change the polarization of the two beams of light, so that the two beams of light can be combined by the polarization combining component 212. The intermediate light obtained after beam combining is polarized by the third polarizer 220, so that part of the Raman master laser and part of the Raman slave laser have the same polarization state. When the intermediate light passes through the polarization splitter 221, the part of the Raman master laser and part of the Raman slave laser with the same polarization state are separated as Raman light. Since the polarization states of the two beams of light are perpendicular to each other after passing through the first polarizer 210 and the second polarizer 211, the third polarizer 220 cannot completely convert the two beams of light into the same polarization state. There must still be some light with different polarization states. These lights are separated as redundant light. By controlling the third polarizer 220, the splitting ratio of the two beams of light to obtain Raman light and redundant light can be controlled. The light after passing through the polarization wave splitter 221 is split into two beams. One beam is output as Raman light with a frequency difference of approximately Δf4, such as Δf4 = 3.036 GHz. The other beam undergoes positive frequency shifting through the first acousto-optic modulation component 31. The first acousto-optic modulation component 31 operates at a frequency of Δf3, which can be 1467 MHz. This shifts the Raman light from the laser frequency to the transition frequency F = 2 -> F' = 3, serving as the pump back light. A third collimating component 5 and a fourth collimating component 6 are added before and after the first acousto-optic modulation component 31 to focus the light spot and enhance the diffraction efficiency of the first acousto-optic modulation component 31. In one embodiment, multiple cascaded AOMs or multi-path frequency shifting can be used, or an electro-optic modulator (EOM) can be employed to shift the Raman light from the laser frequency or modulate a sideband of Δf3, thereby replacing the frequency shifting function of the first acousto-optic modulation component 31 and obtaining the pump back light.

[0098] To achieve two-photon Raman transitions, the ratio of the Raman laser beam is typically set to a certain value to suppress the AC Stark frequency shift. This requires controlling the first polarizer 210, the second polarizer 211, and the third polarizer 220. Figure 6 In the optical path structure, one of the two beams after passing through the polarization wave division component 221 is used as Raman light, and the other beam is redundant light. In this invention, this redundant light is used to generate pump back light, which improves the utilization rate of laser light power and increases the rationality of the allocation of optical power resources in the optical unit of the atomic interferometer.

[0099] During the operation of the atomic interferometer, frequency-shift keying (FSK) can be performed on the second acousto-optic modulation component 11 to achieve chirped scanning of the Raman laser frequency and measure inertial quantities such as gravitational acceleration. This method ensures that the phase noise of the Raman laser mainly depends on the phase noise of the radio frequency source, eliminating the need for beat-locked loops or active feedback. Therefore, while maintaining low phase noise, it is unaffected by external environmental interference and free from phase-locked loops, making it suitable for high-precision atomic interferometers and enhancing the environmental adaptability and long-term stability of the atomic interferometer.

[0100] During the FSK process of the second acousto-optic modulation component 11, in order to maintain the resonant state of the return pump light, the operating frequency of the first acousto-optic modulation component 31 can be shifted by an equal and opposite frequency. The first acousto-optic modulation component 31 can also rapidly switch the return pump light to achieve functions such as rapid normalized detection of atoms.

[0101] After acquiring cooling light, pump-back light, Raman light, etc. with different frequency components, the light enters the beam splitting switch unit 19 according to the requirements of the physical unit interface. For lasers that need to be split or combined, the beam is split or combined and then coupled into the optical fiber or emitted to the vacuum window of the physical unit.

[0102] Each laser output, after passing through the cooling unit 18 and the Raman pumping unit 7, undergoes further processing in the beam splitting unit 19 before being coupled through optical fibers to the corresponding vacuum window of the physical unit. Generally, the cooling light needs to be split into at least six beams to realize a three-dimensional magneto-optical trap. Depending on system requirements, several additional beams can be added to achieve two-dimensional magneto-optical traps, push-up, detection, quenching, and other functions. In the beam splitting unit 19, some of the cooling light needs to be combined with the pumping light to facilitate the realization of a cold atom magneto-optical trap.

[0103] An acousto-optic modulator is added after the Raman laser to rapidly switch the laser and generate Raman pulses. The cooling light is split and its power distributed to achieve functional beams such as two-dimensional magneto-optical trap cooling light, three-dimensional magneto-optical trap cooling light, detection, and propulsion. To avoid the influence of stray light, the radio frequency amplitude of each functional laser can be controlled by adjusting the acousto-optic modulator. To completely shut down each functional beam in certain time sequences to avoid affecting other time sequences, mechanical switches can be added. Each functional laser is ultimately output to the physical unit, i.e., the vacuum system, after fiber coupling.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser generation structure for an atomic interferometer, characterized in that, It includes a Raman laser generation component (1), a wavelength division multiplexing component (2), and a return pump light generation component (3); The first port of the wavelength division multiplexing component (2) is coupled to the main laser output optical path of the Raman laser generating component (1), the second port of the wavelength division multiplexing component (2) is coupled to the slave laser output optical path of the Raman laser generating component (1), and the third port of the wavelength division multiplexing component (2) is coupled to the redundant light output optical path of the return pump light generating component (3). The Raman laser generating component (1) is used to generate a Raman master laser and a Raman slave laser using an incident laser; the wavelength division multiplexing component (2) is used to generate Raman light and redundant light using the Raman master laser and the Raman slave laser; the return pump light generating component (3) is used to positively shift the redundant light to obtain the return pump light; The wavelength division multiplexing component (2) includes a wavelength combining component (21) and a polarization adjustment component (22); the first port of the wavelength combining component (21) is coupled to the Raman master laser output optical path of the Raman laser generating component (1), and the second port of the wavelength combining component (21) is coupled to the Raman slave laser output optical path of the Raman laser generating component (1); the polarization adjustment component (22) is located at the output port of the wavelength combining component (21); the wavelength combining component (21) is used to combine the Raman master laser and the Raman slave laser to obtain intermediate light; the polarization adjustment component (22) is used to adjust the polarization of the intermediate light and to divide the polarization-adjusted intermediate light to obtain Raman light and redundant light; wherein, the Raman light contains part of the Raman master laser and part of the Raman slave laser, and the part of the Raman master laser and part of the Raman slave laser are in the same polarization state; The pump-back light generation component (3) includes a first acousto-optic modulation component (31); the first acousto-optic modulation component (31) performs acousto-optic modulation on the redundant light to obtain the pump-back light; wherein the pump-back light is the positive first-order diffraction light of the redundant light.

2. The laser generation structure for an atomic interferometer according to claim 1, characterized in that, The polarization combining component (21) includes a first polarization component (210), a second polarization component (211), and a polarization combining component (212). The first port of the polarization combining component (212) is coupled to the main laser output optical path of the Raman laser generating component (1), the first polarization initiating component (210) is disposed at the location of the first port of the polarization combining component (212), the second port of the polarization combining component (212) is coupled to the secondary laser output optical path of the Raman laser generating component (1), and the second polarization initiating component (211) is disposed at the location of the second port of the polarization combining component (212). The first polarization component (210) is used to provide polarization in a first direction for the Raman master laser; The second polarization component (211) is used to provide a second direction of polarization for the Raman laser; The polarization combining component (212) is used to combine the Raman master laser with the Raman slave laser with the second polarization to obtain the intermediate light.

3. The laser generation structure for an atomic interferometer according to claim 1, characterized in that, The polarization adjustment component (22) includes a third polarization component (220) and a polarization wave division component (221). The polarization wave splitter component (221) is located at the output port of the wave combiner component (21), and the third polarization component (220) is located between the polarization wave splitter component (221) and the wave combiner component (21). The third polarization component (220) is used to adjust the polarization of the intermediate light so that part of the Raman master laser and part of the Raman slave laser in the polarization-adjusted intermediate light have the same polarization state; The polarization wave division component (221) is used to divide the intermediate light after polarization adjustment, outputting part of the Raman master laser and part of the Raman slave laser with the same polarization state as Raman light, and outputting light other than the Raman light as redundant light.

4. The laser generation structure for an atomic interferometer according to claim 1, characterized in that, The Raman laser generating component (1) includes a second acousto-optic modulation component (11) and a first reflection component (12). The first reflective component (12) is disposed on the non-diffractive optical path opposite to the second acousto-optic modulation component (11); The incident laser is incident from the side of the second acousto-optic modulation component (11), which is used to perform acousto-optic modulation on the incident laser to obtain a Raman follower laser emitted from the diffraction path on the opposite side of the second acousto-optic modulation component (11) and a zero-order light emitted from the non-diffraction path on the opposite side of the second acousto-optic modulation component (11); wherein the Raman follower laser is the positive first-order diffracted light of the incident laser; The first reflective component (12) is used to reflect the zero-order light so that the zero-order light is incident from the opposite side of the second acousto-optic modulation component (11). The second acousto-optic modulation component (11) is also used to perform acousto-optic modulation on the zero-order light to obtain a Raman master laser emitted from the diffraction path on the side of the second acousto-optic modulation component (11). The Raman master laser is the negative first-order diffracted light of the zero-order light.

5. The laser generation structure for an atomic interferometer according to claim 4, characterized in that, The Raman laser generating component (1) further includes a second reflection component (13), a third reflection component (14) and a fourth reflection component (15). The second reflective component (13) is disposed on the diffraction path on the same side of the second acousto-optic modulation component (11), the third reflective component (14) is disposed on the diffraction path on the opposite side of the second acousto-optic modulation component (11), and the fourth reflective component (15) is optically coupled to the third reflective component (14). The second reflection component (13) is used to reflect the Raman master laser to the first port of the wavelength division multiplexing component (2), the third reflection component (14) is used to reflect the Raman from the laser to the fourth reflection component (15), and the fourth reflection component (15) is used to reflect the Raman from the laser to the second port of the wavelength division multiplexing component (2).

6. The laser generation structure for an atomic interferometer according to claim 4, characterized in that, The Raman laser generating component (1) further includes a first collimation component (16) and a second collimation component (17); The first collimation component (16) is disposed on the same side as the second acousto-optic modulation component (11) and is used to focus the incident laser and the Raman master laser. The second collimation component (17) is disposed on the opposite side of the second acousto-optic modulation component (11) and is used to focus the zero-order light and the Raman slave laser.

7. A laser generating device for an atomic interferometer, characterized in that, It includes a Raman pump-back unit (7), a single laser (8), an amplifier (9), a frequency-locking unit (10), a cooling unit (18), and a beam-splitting switch unit (19); wherein the Raman pump-back unit (7) is the laser generation structure for an atomic interferometer as described in any one of claims 1-6; The frequency locking unit (10) is used to lock the frequency of the single laser (8); The single laser (8) is used to generate an initial laser, and the amplifier (9) is used to amplify the initial laser to obtain an amplified laser; The cooling unit (18) is used to generate cooling light using a portion of the amplified laser; Another portion of the amplified laser is transmitted as the incident laser to the Raman pumping unit (7), which is used to generate Raman light and pumping light using the incident laser. The beam splitting switch unit (19) is used to combine and split the pump back light, cooling light and Raman light to obtain the light required to realize the atomic interferometer.

8. An atomic interferometer, characterized in that, It includes the laser generating structure for an atomic interferometer as described in any one of claims 1-6, or the laser generating device for an atomic interferometer as described in claim 7.

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