Multi-mode switching stimulated Raman transition laser system and use method thereof

Abstract

The invention relates to the technical field of cold atoms, in particular to a multi-mode switching stimulated Raman transition laser system and a use method thereof. The system comprises a master laser, a slave laser and a plurality of switches arranged on the propagation path of the master laser and the propagation path of the slave laser respectively. Master laser emitted by the master laser is divided into first master laser and second master laser, and slave laser emitted by the slave laser is divided into first slave laser and second slave laser; the first master laser and the first slave laser are selectively transmitted to the first beam combining element under the control of the corresponding optical switches, and the second master laser and the second slave laser are selectively transmitted to the second beam combining element under the control of the corresponding optical switches. According to the invention, the on-off state of the optical switch is subjected to combined control, so that one machine has multiple functions without changing the core structure of an optical path, the adaptability and application flexibility of the system in a scene in which the configuration of an optical field needs to be frequently switched are improved, and the complexity and the cost of repeated construction of a plurality of sets of systems are avoided.

Description

Technical Field

[0001] This invention relates to the field of cold atom technology, and in particular to a multi-mode switching stimulated Raman transition laser system and its usage method. Background Technology

[0002] Stimulated Raman transitions are a key technology in precision measurement fields such as cold atom physics and atomic interferometers. This process utilizes two laser beams (collectively known as Raman beams) whose frequency difference is precisely matched to the splitting distance of the hyperfine energy level of the atomic ground state and which have a fixed phase relationship to interact with the atom.

[0003] In existing technologies, systems for generating Raman light are typically designed to produce and output Raman light in a fixed spatial mode. Common modes include aligning two laser beams and outputting them in the same direction, or outputting them from two opposing directions. However, when experimental requirements change, such as altering the relative interaction direction between atoms and Raman light, or requiring measurements in different directions, existing systems lack the ability to quickly and flexibly switch between different emission modes.

[0004] To adapt to different directional requirements, operators usually need to manually adjust, switch, or reconstruct the optical path. This physical modification is not only cumbersome and time-consuming, but also inevitably introduces optical path alignment errors and additional phase noise, which seriously affects the efficiency of the experiment and the repeatability and reliability of the measurement results.

[0005] Therefore, overcoming the shortcomings of the existing technology is an urgent problem to be solved in this technical field. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to address the difficulty in achieving flexible switching of multiple modes in a single system architecture for stimulated Raman transition laser systems in the prior art.

[0007] In a first aspect, embodiments of the present invention provide a multi-mode switching stimulated Raman transition laser system, comprising: Master laser 1, slave laser 2, first optical switch 21, second optical switch 22, third optical switch 23 and fourth optical switch 24; The main laser emitted by the main laser 1 is divided into a first main laser and a second main laser; the slave laser emitted by the slave laser 2 is divided into a first slave laser and a second slave laser. The first optical switch 21 is disposed on the propagation path of the first main laser. The first main laser is controlled by the first optical switch 21 to selectively continue to propagate backward to the first beam combining element 31. The second optical switch 22 is disposed on the propagation path of the second main laser. The second main laser is controlled by the second optical switch 22 to selectively continue propagating backward to the second beam combining element 32. The third optical switch 23 is disposed on the propagation path of the first laser, and the first laser is controlled by the third optical switch 23 to selectively continue propagating backward to the first beam combining element 31; the fourth optical switch 24 is disposed on the propagation path of the second laser, and the second laser is controlled by the fourth optical switch 24 to selectively continue propagating backward to the second beam combining element 32. The switching of different working modes is achieved through the combination of switch states formed by the first optical switch 21, the second optical switch 22, the third optical switch 23 and the fourth optical switch 24.

[0008] Furthermore, it also includes a first beam splitting element 12 coupled to the main laser 1 and a second beam splitting element 13 coupled to the slave laser 2; The first beam splitter 12 is used to split the main laser into a first main laser and a second main laser; The second beam splitter 13 is used to split the laser beam into a first laser beam and a second laser beam.

[0009] Furthermore, it also includes a third beam splitter 14 coupled to the first beam combiner 31, a fourth beam splitter 15 coupled to the second beam combiner 32, and a phase-locked module 8 connected to the laser 2; The third beam splitter 14 is used to split the first beam combined output by the first beam combining element 31 into a first sub-beam combined and a second sub-beam combined, wherein the first sub-beam combined continues to propagate backward, and the second sub-beam combined propagates to the phase-locked module 8. The fourth beam splitter 15 is used to split the second beam combined output by the second beam combining element 32 into a third sub-beam combined and a fourth sub-beam combined, wherein the third sub-beam combined continues to propagate backward, and the fourth sub-beam combined propagates to the phase-locked module 8. The phase-locked module 8 is used to perform phase locking on the slave laser 2 based on the second sub-beam combiner and the fourth sub-beam combiner.

[0010] Furthermore, the phase-locked module 8 includes a beat frequency detector 81 and an optical phase-locked loop 82. The output terminal of the beat frequency detector 81 is connected to the input terminal of the optical phase-locked loop 82, and the output terminal of the optical phase-locked loop 82 is connected to the slave laser 2. The beat frequency detector 81 is used to detect the beat frequency of the second sub-beam combiner and the fourth sub-beam combiner, and the optical phase-locked loop 82 is used to phase-lock the slave laser 2 according to the detection result.

[0011] Furthermore, it also includes a second acousto-optic frequency shifter 4, a first coupling head 25, a first optical fiber 6, and a first collimator 27, which are sequentially coupled along the optical path; wherein, the second acousto-optic frequency shifter 4 is used to receive the first sub-beam combined light and perform frequency shift modulation on the first sub-beam combined light.

[0012] Furthermore, it also includes a third acousto-optic frequency shifter 5, a second coupling head 26, a second optical fiber 7, and a second collimator 28, which are sequentially coupled along the optical path; The third acousto-optic frequency shifter 5 is used to receive the third sub-beam combined light and perform frequency shift modulation on the third sub-beam combined light.

[0013] Furthermore, it also includes a first acousto-optic frequency shifter 3 and a frequency stabilization module 11 connected to the main laser 1; The first acousto-optic frequency shifter 3 is used to receive the main laser and shift the frequency of the main laser to obtain frequency-shifted light, which continues to propagate to the frequency stabilization module 11; The frequency stabilization module 11 is used to lock the frequency of the main laser emitted by the main laser 1 using the frequency-shifted light as a reference.

[0014] Secondly, the present invention also provides a method of using a multi-mode switching stimulated Raman transition laser system, comprising: The first optical switch 21 and the third optical switch 23 are turned on, and the second optical switch 22 and the fourth optical switch 24 are turned off, so that the stimulated Raman transition laser system is in a first working mode; or, the second optical switch 22 and the fourth optical switch 24 are turned on, and the first optical switch 21 and the third optical switch 23 are turned off, so that the stimulated Raman transition laser system is in a first working mode. The first optical switch 21 and the fourth optical switch 24 are turned on, and the second optical switch 22 and the third optical switch 23 are turned off, so that the stimulated Raman transition laser system is in the second working mode; The second optical switch 22 and the third optical switch 23 are turned on, and the first optical switch 21 and the fourth optical switch 24 are turned off, so that the stimulated Raman transition laser system is in the third working mode.

[0015] Furthermore, the method also includes: The output frequency of the main laser 1 is locked to a predetermined atomic transition spectral line by the frequency stabilization module 11, and the main laser modulated by the first acousto-optic frequency shifter 3 and the frequency stabilization module 11 is used as the frequency reference to perform phase locking on the slave laser 2, so that a fixed frequency difference and a stable phase relationship are generated and maintained between the lasers output by the main laser 1 and the slave laser 2. The first beam combined by the first beam combining element 31 is split into a first sub-beam combined and a second sub-beam combined by the third beam splitter 14; the second beam combined by the second beam combining element 32 is split into a third sub-beam combined and a fourth sub-beam combined by the fourth beam splitter 15. The first sub-beam beam is frequency-shifted and modulated by controlling the second acousto-optic frequency shifter 4; the third sub-beam beam is frequency-shifted and modulated by the third acousto-optic frequency shifter 5 to generate Raman light with a predetermined frequency configuration and timing characteristics, which is then output via the first collimator 27 and the second collimator 28.

[0016] Furthermore, the method also includes: The main laser output from the main laser 1 is introduced into the first acousto-optic frequency shifter 3, and the main laser is frequency-shifted and modulated to obtain frequency-shifted light, which is then input to the frequency stabilization module 11. The frequency stabilization module 11, based on the frequency-shifting light, controls the main laser 1 through feedback, so that the output frequency of the main laser 1 is locked at a predetermined atomic transition spectrum line; The second sub-beam combiner and the fourth sub-beam combiner are jointly guided into the beat frequency detector 81; The beat frequency detector 81 performs beat frequency detection on the second sub-beam combiner and the fourth sub-beam combiner, and generates a corresponding beat frequency signal. The beat frequency signal is input to the optical phase-locked loop 82, which generates an error signal and feeds the error signal back to the slave laser 2 for phase modulation and control.

[0017] Compared with the prior art, the beneficial effects of the embodiments of the present invention are as follows: by combining and controlling the switching states of the above-mentioned optical switches, flexible switching between different working modes of the system can be realized. Without changing the core structure of the optical path, one machine can achieve multiple functions, improving the adaptability and application flexibility of the system in scenarios where the optical field configuration needs to be frequently switched, and avoiding the tediousness and cost of repeatedly building multiple systems. Attached Figure Description

[0018] 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.

[0019] Figure 1 This is a schematic diagram of the structure of a multi-mode switching stimulated Raman transition laser system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the overall structure of a multi-mode switching stimulated Raman transition laser system provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of Raman light emitted from the first collimator in the first working mode of a multi-mode switching stimulated Raman transition laser system provided by the present invention. Figure 4 This is a schematic diagram of Raman light emitted from the second collimator in the first operating mode of a multi-mode switching stimulated Raman transition laser system provided by the present invention. Figure 5 This is a schematic diagram of the second operating mode of a multi-mode switching stimulated Raman transition laser system provided by the present invention; Figure 6 This is a schematic diagram of the third working mode of a multi-mode switching stimulated Raman transition laser system provided by the present invention; Figure 7 This is a schematic diagram of the structure of a multi-mode switching stimulated Raman transition laser system provided in two embodiments of the present invention; Figure 8 This is a schematic diagram of the overall structure of a multi-mode switching stimulated Raman transition laser system provided in two embodiments of the present invention; Figure 9 This is a schematic diagram of the overall structure of a multi-mode switching stimulated Raman transition laser system provided in three embodiments of the present invention; Figure 10 This is a flowchart illustrating the usage method of the multi-mode switching stimulated Raman transition laser system provided in four embodiments of the present invention.

[0020] The accompanying diagram is described as follows: The system comprises: a master laser 1, a slave laser 2, a frequency stabilization module 11, a first beam splitter 12, a second beam splitter 13, a third beam splitter 14, a fourth beam splitter 15, a first acousto-optic frequency shifter 3, a second acousto-optic frequency shifter 4, a third acousto-optic frequency shifter 5, a first optical switch 21, a second optical switch 22, a third optical switch 23, a fourth optical switch 24, a first coupling head 25, a second coupling head 26, a first collimator 27, a second collimator 28, a first optical fiber 6, a second optical fiber 7, a phase-locked loop module 8, a beat frequency detector 81, an optical phase-locked loop 82, a first beam combiner 31, a second beam combiner 32, a first reflector 33, and a second reflector 34. Detailed Implementation

[0021] 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.

[0022] Unless the context otherwise requires, throughout the specification and claims, the term "comprising" is interpreted as open-ended, meaning "including, but not limited to." In the description, terms such as "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples" are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the invention. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples; that is, although they may be incorporated into embodiments or examples using the above terms due to reasons such as order and position, it does not limit them to be incorporated in combination by a single embodiment or example.

[0023] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", 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 simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] In the description of this invention, the terms "first" and "second" 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. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, for example, the description may use the prefix "A" or "B" to describe the same type of nouns as two independent entities. In this case, the features defined with "A" and "B" are used only to distinguish between similar entities and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features.

[0025] In describing some embodiments, the terms "coupled," "coupled," and "connected," and their derivative expressions, may be used. For example, the term "connected" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact with each other. Similarly, the term "coupled" may be used in describing some embodiments to indicate that two or more components have direct physical or electrical contact. However, the terms "connected" or "coupled" may also refer to two or more components that do not have direct contact with each other but still cooperate or interact with each other, such as "optical coupling," "wireless connection," etc. The embodiments disclosed herein are not necessarily limited to the scope of this invention.

[0026] As used in this invention, “about,” “approximately,” or “approximately” includes the stated value and the average value within an acceptable range of deviation from a particular value, wherein the acceptable range of deviation is determined by a person skilled in the art taking into account the measurement under discussion and the error associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0027] Example 1: See Figure 1As shown, a multi-mode switching stimulated Raman transition laser system includes: a master laser 1, a slave laser 2, a first optical switch 21, a second optical switch 22, a third optical switch 23, and a fourth optical switch 24; the master laser emitted by the master laser 1 is divided into a first master laser and a second master laser; the slave laser emitted by the slave laser 2 is divided into a first slave laser and a second slave laser; the first optical switch 21 is disposed on the propagation path of the first master laser, and the first master laser is controlled by the first optical switch 21 to selectively continue propagating backward to a first beam combiner 31; the second optical switch 22 is disposed on the propagation path of the second master laser, and the second master laser is controlled by the second optical switch 24. The first laser beam is controlled by switch 22 to selectively continue propagating backward to the second beam combiner 32; the third optical switch 23 is disposed on the propagation path of the first laser beam, and the first laser beam is controlled by the third optical switch 23 to selectively continue propagating backward to the first beam combiner 31; the fourth optical switch 24 is disposed on the propagation path of the second laser beam, and the second laser beam is controlled by the fourth optical switch 24 to selectively continue propagating backward to the second beam combiner 32; wherein, the switching state combination formed by the first optical switch 21, the second optical switch 22, the third optical switch 23 and the fourth optical switch 24 realizes the switching of different working modes.

[0028] Reference Figures 3-6 As shown, the stimulated Raman transition laser system has multiple operating modes, including: First operating mode: Control the first optical switch 21 and the third optical switch 23 to be turned on, and control the second optical switch 22 and the fourth optical switch 24 to be turned off; or, control the second optical switch 22 and the fourth optical switch 24 to be turned on, and control the first optical switch 21 and the third optical switch 23 to be turned off.

[0029] Second operating mode: Control the first optical switch 21 and the fourth optical switch 24 to be turned on, and control the second optical switch 22 and the third optical switch 23 to be turned off.

[0030] Third operating mode: Control the second optical switch 22 and the third optical switch 23 to be turned on, and control the first optical switch 21 and the fourth optical switch 24 to be turned off.

[0031] By splitting the output light from the master laser 1 and the slave laser 2 into two paths, and setting a first optical switch 21, a second optical switch 22, a third optical switch 23, and a fourth optical switch 24 on each propagation path, the master and slave lasers can be selectively combined at different combining elements. By combining and controlling the on / off states of the above four optical switches, rapid switching between different modes can be achieved without changing the physical structure of the optical devices, thereby improving the system's flexibility and configurability.

[0032] In another embodiment, refer to Figure 1 As shown, the stimulated Raman transition laser system further includes a first beam splitter 12 coupled to the master laser 1 and a second beam splitter 13 coupled to the slave laser 2. The first beam splitter 12 splits the master laser into a first master laser and a second master laser; the second beam splitter 13 splits the slave laser into a first slave laser and a second slave laser. By splitting the master laser and the slave laser into two laser branches, multiple optical paths can be constructed using only one master laser 1 and one slave laser 2. Combined with the state switching of the optical switch, flexible selection of different operating modes can be achieved, thereby improving the operating mode multiplexing capability and system stability of the stimulated Raman transition laser system.

[0033] In a preferred embodiment, refer to Figure 1As shown, the stimulated Raman transition laser system further includes a third beam splitter 14 coupled to the first beam combiner 31, a fourth beam splitter 15 coupled to the second beam combiner 32, and a phase-locked module 8 connected to the slave laser 2. The third beam splitter 14 is used to split the first beam combined output by the first beam combiner 31 into a first sub-beam combined and a second sub-beam combined, wherein the first sub-beam combined continues to propagate backward, and the second sub-beam combined propagates to the phase-locked module 8. The fourth beam splitter 15 is used to split the second beam combined output by the second beam combiner 32 into a third sub-beam combined and a fourth sub-beam combined, wherein the third sub-beam combined continues to propagate backward, and the fourth sub-beam combined propagates to the phase-locked module 8. The phase-locked module 8 is used to perform phase locking on the slave laser 2 based on the second sub-beam combined and the fourth sub-beam combined. By correspondingly configuring a third beam-splitting element 14 and a fourth beam-splitting element 15 in the first beam-combining element 31 and the second beam-combining element 32, the combined light is divided into a first sub-beam-combined light and the third sub-beam-combined light for subsequent propagation; and a second sub-beam-combined light and the fourth sub-beam-combined light for phase locking. The second sub-beam-combined light and the fourth sub-beam-combined light are then introduced into the phase-locked module 8. The phase-locked module 8 performs phase locking on the slave laser 2, enabling the slave laser 2 to maintain a stable phase relationship with the master laser 1 under multi-mode switching conditions. This is beneficial for ensuring the stable realization of the stimulated Raman transition process in different operating modes.

[0034] In a preferred embodiment, refer to Figure 2 As shown, the phase-locked module 8 includes a beat frequency detector 81 and an optical phase-locked loop 82. The output of the beat frequency detector 81 is connected to the input of the optical phase-locked loop 82, and the output of the optical phase-locked loop 82 is connected to the slave laser 2. The beat frequency detector 81 is used to detect the beat frequency of the second sub-beam combined beam and the fourth sub-beam combined beam, and the optical phase-locked loop 82 is used to perform phase locking on the slave laser 2 based on the detection results.

[0035] The beat frequency detector 81 is a device used to detect the frequency difference between two optical signals. Its working principle is based on the interference effect; when two optical signals with different frequencies meet, a beat frequency signal is generated in their combined waveform, the frequency of which is the difference between the two frequencies. The beat frequency detector 81 achieves accurate detection of the frequency difference between the two optical signals by measuring the frequency of this beat frequency signal. An optical phase-locked loop (OPLL) is a feedback system used to precisely control the phase of an optical signal. It adjusts the phase of the laser source based on the detected frequency or phase difference of the optical signal through a feedback loop, maintaining a stable frequency and phase relationship between the signal sources. In this embodiment, by using the combination of the beat frequency detector 81 and the optical phase-locked loop 82, the phase of the slave laser 2 can be detected and adjusted. The beat frequency detector 81 can measure the frequency difference between the second and fourth sub-combined beams, while the optical phase-locked loop 82 locks the phase of the slave laser 2 based on the detected frequency difference. The combination of the beat frequency detector 81 and the optical phase-locked loop 82, through real-time detection and phase control of the frequency difference, ensures a stable frequency and phase relationship between the slave laser 2 and the master laser 1 in various operating modes. Even when the frequency difference between the lasers changes, the system can automatically adjust. This phase-locked module 8, in conjunction with the beat frequency detector 81 and the optical phase-locked loop 82, allows the system to adapt to different operating requirements by rapidly adjusting the phase-locked state during various mode switching. This design improves the system's adaptability.

[0036] During the operation of the phase-locked module 8, the beat frequency detector 81 receives the second sub-beam combined light from the third beam splitter 14 and the fourth sub-beam combined light from the fourth beam splitter 15. Because the first optical switch 21, the second optical switch 22, the third optical switch 23, and the fourth optical switch 24 have multiple on / off state combinations, the components of the two optical signals input to the beat frequency detector 81 will change under different operating modes. (Refer to...) Figures 3-6 As shown, specifically, depending on the state of the optical switch, there are four possible combinations of the two optical signals actually entering the beat frequency detector: the first master laser and the first slave laser, the first master laser and the second slave laser, the second master laser and the first slave laser, or the second master laser and the second slave laser. The beat frequency detector 81 performs beat frequency detection on the two actual input lights with a frequency difference in any of the above four cases. The optical phase-locked loop 82 generates an error signal based on the beat frequency signal output by the beat frequency detector 81 and feeds it back to control the slave laser 2, thereby achieving precise phase locking of the slave laser 2 relative to the master laser 1 in various operating modes, ensuring the phase stability of the Raman light in different emission modes of the system.

[0037] In a preferred embodiment, the beat frequency detector 81 is a phototube. A phototube is a photoelectric device based on the external photoelectric effect. It generates photoelectrons by exciting the cathode material with photons, forming a photocurrent proportional to the incident light intensity, thereby converting the optical signal into an electrical signal. In the beat frequency detection scenario, when two laser beams with similar frequencies interfere on the cathode surface of the phototube, the light intensity will fluctuate periodically with the beat frequency. The phototube converts this fluctuation into a current change, which is then amplified and the difference frequency component is extracted. The phototube can perform beat frequency detection on the second sub-beam and the fourth sub-beam and feed back the obtained beat frequency electrical signal to the optical phase-locked loop 82, thereby achieving effective adjustment of the phase-locked process and improving the stability and response speed of the phase-locked system.

[0038] In another embodiment, refer to Figure 2 As shown, the stimulated Raman transition laser system further includes a second acousto-optic frequency shifter 4, a first coupling head 25, a first optical fiber 6, and a first collimator 27 coupled sequentially along the optical path; wherein, the second acousto-optic frequency shifter 4 is used to receive the first sub-beam combined light and perform frequency shift modulation on the first sub-beam combined light.

[0039] An acousto-optic frequency shifter is an optical device based on the acousto-optic effect, used to adjust the frequency of optical signals. The acousto-optic effect refers to the phenomenon where, when ultrasound passes through an optical medium, the density wave generated by the sound wave affects the propagation of light in that medium, causing a change in the light frequency. By changing the frequency of the sound wave in the acousto-optic frequency shifter, the frequency of the light is also adjusted accordingly. In this embodiment, the second acousto-optic frequency shifter 4 receives the first sub-beam combined light after the first beam combining and modulates the frequency of the first sub-beam combined light. This allows the first sub-beam combined light to be precisely tuned to the required frequency, thereby optimizing the frequency matching in the stimulated Raman transition process and improving the Raman efficiency and output power of the system. Through precise frequency modulation, it is ensured that the optical signal maintains a stable frequency relationship when passing through various optical components and media, avoiding phase lock-up caused by frequency drift, thereby enhancing the stability of the system.

[0040] In an optional embodiment, refer to Figure 2 As shown, the stimulated Raman transition laser system further includes a third acousto-optic frequency shifter 5, a second coupling head 26, a second optical fiber 7, and a first collimator 28, which are coupled sequentially along the optical path; wherein, the third acousto-optic frequency shifter 5 is used to receive the third sub-beam combined light and perform frequency shift modulation on the third sub-beam combined light.

[0041] In this embodiment, the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5 are used to modulate the frequency of the sub-beams on different paths. Specifically, the second acousto-optic frequency shifter 4 receives the first sub-beam and modulates its frequency; the third acousto-optic frequency shifter 5 receives the third sub-beam and modulates its frequency. After the frequency modulation, the first and third sub-beams are transmitted and collimated sequentially through optical fibers and collimators in subsequent optical paths. By adjusting the frequencies of the first and third sub-beams using the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5 respectively, the frequency shift of the two beams in the Raman light can be independently controlled, matching the frequency difference with the energy level difference corresponding to the preset atomic transition spectral lines, thereby achieving precise adjustment of the single-photon detuning of the Raman light. Furthermore, by combining and adjusting the frequency shifts of the two acousto-optic frequency shifters, the total frequency shift of the Raman light can be adjusted to the target value, meeting the requirements for detuning under different experimental conditions. In addition, the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5 act on different optical paths, enabling the system to independently modulate the frequencies of multiple optical paths, supporting flexible switching of multiple Raman operating modes, and improving the frequency stability of the system under multi-path and multi-mode operating conditions.

[0042] In a preferred embodiment, refer to Figure 2 As shown, the stimulated Raman transition laser system further includes a first acousto-optic frequency shifter 3 and a frequency stabilization module 11 connected to the main laser 1. The first acousto-optic frequency shifter 3 receives the main laser and shifts its frequency to obtain frequency-shifted light, which then propagates to the frequency stabilization module 11. The frequency stabilization module 11 uses the frequency-shifted light as a reference to lock the frequency of the main laser emitted by the main laser 1. By setting the first acousto-optic frequency shifter 3 between the main laser 1 and the frequency stabilization module 11, the main laser is first frequency-shifted, and then the frequency-shifted light is introduced into the frequency stabilization module 11. The frequency stabilization module 11 uses the frequency-shifted light as a reference to lock the frequency of the main laser emitted by the main laser 1, so that the frequency of the main laser 1 is near a predetermined atomic transition spectral line. This allows the main laser 1 to maintain a stable frequency lock while its output frequency can be finely adjusted by the first acousto-optic frequency shifter 3, thereby providing a stable and adjustable frequency reference for the subsequent Raman light frequency configuration and detuning setting, which is beneficial to improving the frequency stability and adjustment flexibility of the stimulated Raman transition laser system.

[0043] Example 2: See Figure 7 As shown, this embodiment employs an optical fiber path. This invention provides a multi-mode switching stimulated Raman transition laser system, comprising: The system comprises a master laser 1, a slave laser 2, a first acousto-optic frequency shifter 3, a second acousto-optic frequency shifter 4, a third acousto-optic frequency shifter 5, a first collimator 27, a second collimator 28, a phase-locked loop module 8, a frequency stabilization module 11, and an optical switch. An acousto-optic frequency shifter is a device that utilizes the acousto-optic effect to achieve precise control of the laser frequency. Its core function is to superimpose the frequency of an applied radio frequency signal onto the laser frequency through acousto-optic interaction, thereby changing the frequency properties of the laser.

[0044] The light output by the main laser 1 is selectively transmitted to the first acousto-optic frequency shifter 3, the second acousto-optic frequency shifter 4, and the third acousto-optic frequency shifter 5. The first acousto-optic frequency shifter 3 transmits the frequency-shifted light to the frequency stabilization module 11. The electrical signal output terminal of the frequency stabilization module 11 is connected to the electrical signal input terminal of the main laser 1.

[0045] The output light of the main laser 1, after being frequency-shifted by the first acousto-optic frequency shifter 3, is introduced into the frequency stabilization module 11 for frequency locking. The frequency stabilization module 11 uses the frequency-shifted light as a reference to lock the frequency of the main laser emitted by the main laser 1. This improves the frequency stability of the output light of the main laser 1, providing a stable frequency reference for subsequent Raman light generation and frequency modulation. The frequency stabilization method of the frequency stabilization module depends on the actual use by those skilled in the art; it can be achieved through saturated absorption frequency stabilization, polarization spectral frequency stabilization, or Pound-Dreyfus-Hall frequency stabilization, among others.

[0046] Reference Figure 7As shown, the light output from laser 2 is selectively transmitted to the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5. The second acousto-optic frequency shifter 4 transmits the frequency-shifted light to the first collimator 27, and the third acousto-optic frequency shifter 5 transmits the frequency-shifted light to the second collimator 28. A collimator is an optical device whose core function is to convert divergent light beams (such as laser light, LED light, etc.) into parallel light beams, or to focus and shape parallel light beams to optimize the propagation characteristics of the beam. Here, by setting the first collimator 27 and the second collimator 28, the beams output from different acousto-optic frequency shifters are independently collimated, which helps to improve the parallelism and consistency of the beams and provides a stable and controllable beam direction for different subsequent working modes. The third beam splitter 14 is positioned before the second acousto-optic frequency shifter 4 and is used to receive the beams from the master laser 1 and the slave laser 2. A portion of the beams is split and injected into the phase-locked module 8. The fourth beam splitter 15 is positioned before the third acousto-optic frequency shifter 5 and is used to receive the beams from the master laser 1 and the slave laser 2. A portion of the beams is split and injected into the phase-locked module 8. The electrical signal output terminal of the phase-locked module 8 is connected to the slave laser 2. The third beam splitter 14 and the fourth beam splitter 15 are respectively positioned before the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5. They are used to split a portion of the beam from the combined beam of the master laser 1 and the slave laser 2. The split beams are sent into the phase-locked module 8 to lock the phase relationship between the master laser 1 and the slave laser 2. Optical switches are provided between the optical paths of the master laser 1 and the slave laser 2 and the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5. By controlling the on / off states of different optical switches, the selection and combination of optical paths can be achieved, thereby enabling the system to switch between multiple working modes under the same hardware architecture.

[0047] In this embodiment, the invention employs a master-slave laser architecture. The master laser 1 serves as the frequency reference, ensuring high frequency stability of its output laser. The frequency and phase of the laser output from the slave laser 2 are locked to a frequency with a specific offset from that of the master laser 1 by multiple acousto-optic frequency shifters and a phase-locked loop module 8. This enables the system to generate two Raman beams that meet the requirements for stimulated Raman transition. By setting optical switches between the master laser 1 and slave laser 2 and the second and third acousto-optic frequency shifters 4 and 5, respectively, the optical paths can be flexibly selected and combined without changing the overall system structure, thereby achieving switching between multiple operating modes. Simultaneously, by placing a beam splitter before the second and third acousto-optic frequency shifters 4 and 5, and introducing the split beam into the phase-locked loop module 8, the phase relationship between the master laser 1 and slave laser 2 is locked, improving the frequency stability and operational reliability of the system under different operating modes. Therefore, this invention achieves multi-mode output of stimulated Raman transition light within the same laser system architecture, offering advantages such as compact structure, flexible mode switching, and high system stability.

[0048] In a preferred embodiment, such as Figure 8 As shown, the phase-locked module 8 includes an optical phase-locked loop 82 and a beat frequency detector 81. The beat frequency detector 81 receives the optical signals split from the third beam splitter 14 and the fourth beam splitter 15. The electrical signal output terminal of the beat frequency detector 81 is connected to the electrical signal input terminal of the optical phase-locked loop 82, and the electrical signal output terminal of the optical phase-locked loop is connected to the slave laser 2. When two laser beams with similar frequencies meet, they will interfere. The intensity of the detected optical signal will change periodically with time. The frequency of this intensity change is called the beat frequency, and its frequency value is equal to the difference between the frequencies of the two incident beams. The beat frequency detector 81 is an indirect detection method. By combining the two laser beams and causing a beat frequency, the laser frequency difference that cannot be directly detected is reduced to a detectable difference frequency signal, while retaining the phase and spectral information of the signal to be measured. Using an optical phase-locked loop 82 and a beat frequency detector 81, the optical input end of the beat frequency detector 81 can simultaneously receive light output from the third beam splitter 14 and the fourth beam splitter 15, and the beat frequency signal is fed back to the optical phase-locked loop 82 through the beat frequency detector 81. The optical phase-locked loop 82 can perform phase-locked control on the slave laser 2 based on the beat frequency signal, thereby improving the frequency stability and phase-locking accuracy of the slave laser 2.

[0049] In a preferred embodiment, such as Figure 7 As shown, the optical switch includes a first optical switch 21, a second optical switch 22, a third optical switch 23, and a fourth optical switch 24.

[0050] A first optical switch 21 is provided between the optical paths of the main laser 1 and the second acousto-optic frequency shifter 4, and a second optical switch 22 is provided between the optical paths of the main laser 1 and the third acousto-optic frequency shifter 5.

[0051] A third optical switch 23 is provided between the optical path of the slave laser 2 and the second acousto-optic frequency shifter 4, and a fourth optical switch 24 is provided between the optical path of the slave laser 2 and the third acousto-optic frequency shifter 5. In this embodiment, by controlling the conduction state of the first optical switch 21 and the second optical switch 22, an optical path connection is selectively established between the master laser 1 and the second acousto-optic frequency shifter 4 or the third acousto-optic frequency shifter 5; then, by controlling the conduction state of the third optical switch 23 and the fourth optical switch 24, an optical path connection is selectively established between the slave laser 2 and the second acousto-optic frequency shifter 4 or the third acousto-optic frequency shifter 5, thereby realizing flexible switching between the master laser 1 and the slave laser 2 and different acousto-optic frequency shifters. By selecting and switching the optical path through optical switches, the optical path combination between the laser and the acousto-optic frequency shifter can be changed without physical adjustment of the optical components, improving the flexibility and scalability of the system configuration; at the same time, it is beneficial to quickly switch the optical path state according to different working modes or experimental requirements, improving the system's working efficiency and operational stability.

[0052] In another embodiment, a first conical amplifier is disposed before the second acousto-optic frequency shifter 4, and a second conical amplifier is disposed before the third acousto-optic frequency shifter 5. The conical amplifier is a specially designed semiconductor optical amplifier whose core function is to amplify the power of a single-mode seed light source while preserving the excellent spectral characteristics of the seed light. In this embodiment, both the first and second conical amplifiers are optical devices used to amplify the incident light signal, enabling them to amplify the input laser signal while maintaining beam quality. By pre-amplifying the light entering the second and third acousto-optic frequency shifters 4 and 5 using the first and second conical amplifiers, the second and third acousto-optic frequency shifters 4 and 5 can operate under appropriate optical power conditions, thereby improving their frequency shifting efficiency and operational stability, and ensuring the overall reliability of the system.

[0053] Example 3: Because the transmission characteristics of optical fibers inevitably degrade the laser beam quality, any bending, stress, or poor mode matching in the fiber will excite higher-order modes, leading to output beam distortion and wavefront distortion. Furthermore, once the fiber optic path is fused and fixed, it cannot be flexibly optimized for collimation and beam size by simply fine-tuning mirrors, unlike spatial optical paths. In this embodiment, as... Figure 9As shown, unlike Embodiments 1 and 2 above, the optical path in this embodiment adopts a spatial optical path. Therefore, the first beam splitter 12, the second beam splitter 13, the third beam splitter 14, the fourth beam splitter 15, the first beam combiner 31, and the second beam combiner 32 in the first and second embodiments are all polarizing beam splitters. A polarizing beam splitter (PBS) is a core optical element that simultaneously possesses beam splitting, beam combining, and reflection capabilities. Its core principle is based on the polarization characteristics of light and thin-film interference. When unpolarized light is incident on a multilayer dielectric film on the prism's inclined plane at a specific angle (usually the Brewster angle), a filtering effect occurs: P-polarized light (whose electric field vector vibration direction is parallel to the incident plane) will pass through the film almost without loss; while S-polarized light (whose electric field vector vibration direction is perpendicular to the incident plane) will be efficiently reflected by the film (reflectivity typically exceeds 90%, and can even reach over 98%). Ultimately, the two beams of light, with their polarization directions perpendicular, will exit from different surfaces of the mirror at a 90-degree angle.

[0054] In a preferred embodiment, such as Figure 9 As shown, the multi-mode switching stimulated Raman transition laser system also includes a first reflector 33 and a second reflector 34. The first reflector 33 and the second reflector 34 are disposed between the second beam splitter 13 and the first beam combiner 31 to assist in optical path connection. This embodiment employs a spatial optical path and combines the first beam splitter 12, the second beam splitter 13, the first beam combiner 31, and the second beam combiner 32 to achieve polarization beam splitting and optical path allocation for the output beams of the main laser 1 and the slave laser 2. This allows the two laser beams to be introduced into the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5 respectively and stably, providing a clear and controllable optical path foundation for subsequent multi-mode switching. Furthermore, by placing the first reflector 33 and the second reflector 34 between the second beam splitter 13 and the first beam combiner 31 to assist in optical path turning and connection, it is beneficial to optimize the optical path layout, reduce the overall structural complexity of the system, and improve the stability of optical path alignment and the reliability of system operation. By introducing two mirrors, the first laser beam can be flexibly redirected around other incoherent elements, ensuring that it is precisely incident on the first beam combining element 31 at the correct angle.

[0055] Example 4: like Figure 10 As shown, based on the above-described solution, the present invention also provides a method for using a multi-mode switching stimulated Raman transition laser system, applicable to the multi-mode switching stimulated Raman transition laser system described in the above-described solution, comprising: Step 10: Control the first optical switch 21 and the third optical switch 23 to be turned on, and control the second optical switch 22 and the fourth optical switch 24 to be turned off, so that the stimulated Raman transition laser system is in the first working mode; or, control the second optical switch 22 and the fourth optical switch 24 to be turned on, and control the first optical switch 21 and the third optical switch 23 to be turned off, so that the stimulated Raman transition laser system is in the first working mode.

[0056] The first working mode is as follows Figure 3 and Figure 4 As shown, the first optical switch 21 and the third optical switch 23 are turned on, and the second optical switch 22 and the fourth optical switch 24 are turned off, so that the stimulated Raman transition laser system is in the first operating mode; refer to Figure 3 In the first operating mode, the lasers emitted from the main laser 1 and the slave laser 2 are emitted through the first collimator 27; (Refer to...) Figure 4 In the first working mode, the lasers emitted from the main laser 1 and the slave laser 2 are both emitted through the second collimator 28; Step 20: Control the first optical switch 21 and the fourth optical switch 24 to be turned on, and control the second optical switch 22 and the third optical switch 23 to be turned off, so that the stimulated Raman transition laser system is in the second working mode.

[0057] Reference Figure 5 As shown, in the second working mode, the laser emitted from the main laser 1 is emitted through the first collimator 27; the laser emitted from the laser 2 is emitted through the second collimator 28. Step 30: Control the second optical switch 22 and the third optical switch 23 to be turned on, and control the first optical switch 21 and the fourth optical switch 24 to be turned off, so that the stimulated Raman transition laser system is in the third working mode.

[0058] Reference Figure 6 As shown, in the third working mode, the laser emitted from the main laser 1 is emitted through the second collimator 28; the laser emitted from the laser 2 is emitted through the first collimator 27. By controlling different on / off combinations of the first optical switch 21, the second optical switch 22, the third optical switch 23, and the fourth optical switch 24, switching between multiple operating modes can be achieved without changing the physical position of the optical components. In the first operating mode, the lasers emitted from the main laser 1 and the slave laser 2 are emitted through the same collimator, causing the two Raman beams to propagate along the same optical path. This helps ensure the spatial overlap of the two beams and improves the stability of the system in this mode. In the second and third operating modes, the lasers emitted from the main laser 1 and the slave laser 2 are emitted through different collimators, causing the two Raman beams to propagate in different directions, thus meeting the requirements for the emission direction and propagation mode of the Raman beams under different experimental conditions. Through the above methods, the stimulated Raman transition laser system can flexibly switch between multiple operating modes according to experimental needs, improving the system's adaptability and operational flexibility.

[0059] In a preferred embodiment, the method of using the stimulated Raman transition laser system further includes: The frequency stabilization module 11 locks the output frequency of the main laser 1 to a predetermined atomic transition spectral line, and uses the main laser modulated by the first acousto-optic frequency shifter 3 and the frequency stabilization module 1 as the frequency reference to perform phase locking on the slave laser 2, so that a fixed frequency difference and a stable phase relationship are generated and maintained between the lasers output by the main laser 1 and the slave laser 2.

[0060] The first beam combined by the first beam combining element 31 is split into a first sub-beam combined and a second sub-beam combined by the third beam splitter 14; the second beam combined by the second beam combining element 32 is split into a third sub-beam combined and a fourth sub-beam combined by the fourth beam splitter 15.

[0061] The first sub-beam beam is frequency-shifted and modulated by controlling the second acousto-optic frequency shifter 4; the third sub-beam beam beam is frequency-shifted and modulated by the third acousto-optic frequency shifter 5 to generate Raman light with a predetermined frequency configuration and timing characteristics, which is then output via the first collimator 27 and the second collimator 28.

[0062] By independently frequency-shifting and modulating the first and third sub-combined beams using the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5, Raman beam frequency and timing control are achieved while maintaining the phase relationship between the master and slave lasers. This process also ensures that the generated Raman beam frequency maintains a large detuning amount with the target atom transition spectral line, optimizing Raman transition efficiency and effectively improving system stability. By controlling this detuning amount, the frequency configuration of the Raman beam can be flexibly adjusted according to different experimental needs to meet the frequency requirements of applications such as atomic interferometry, cold atom, and quantum precision measurement, thereby ensuring high performance and high precision of the system. The detuning amount typically refers to the difference between the laser frequency and the atom transition frequency, which is achieved through frequency modulation in laser systems. If this difference is too small, it may lead to resonance effects; if the detuning amount is appropriate, it can improve transition efficiency and reduce unnecessary interference.

[0063] In a preferred embodiment, the step of locking the output frequency of the main laser 1 to a predetermined atomic transition spectral line via the frequency stabilization module 11, and using the main laser modulated by the first acousto-optic frequency shifter 3 as a frequency reference to perform phase locking on the slave laser 2, thereby generating and maintaining a fixed frequency difference and a stable phase relationship between the lasers output from the main laser 1 and the slave laser 2, includes: The main laser output from the main laser 1 is introduced into the first acousto-optic frequency shifter 3 to perform frequency shift modulation on the main laser, thereby obtaining frequency-shifted light, and the frequency-shifted light is input to the frequency stabilization module 11.

[0064] The frequency stabilization module 11, based on the frequency-shifting light, controls the main laser 1 through feedback, so that the output frequency of the main laser 1 is locked at a predetermined atomic transition spectrum line.

[0065] The second sub-beam combiner and the fourth sub-beam combiner are jointly guided into the beat frequency detector 81.

[0066] The beat frequency detector 81 performs beat frequency detection on the second sub-beam combiner and the fourth sub-beam combiner, generating corresponding beat frequency signals.

[0067] The beat frequency signal is input to the optical phase-locked loop 82, which generates an error signal and feeds it back to the slave laser 2 for phase modulation and control.

[0068] Through the above settings, the frequency-stabilizing module 11 locks the frequency of the frequency-shifting light, and the main laser 1 is controlled by feedback to stably lock its output frequency on a predetermined atomic transition spectrum line, thereby providing a highly stable frequency reference for stimulated Raman transitions. Simultaneously, the combined light output from the first beam combiner 31 and the second beam combiner 32 is split into second and fourth sub-beam combiners by the third beam splitter 14 and the fourth beam splitter 15, respectively, and introduced into the beat frequency detector 81 for beat frequency detection. The slave laser 2 is then controlled by the optical phase-locked loop 82 to maintain a fixed frequency difference and stable phase relationship between the laser output from the slave laser 2 and the frequency-stabilized main laser, thereby improving the phase stability of the Raman light. These settings improve the reliability of the stimulated Raman transition laser system during long-term operation, meeting the requirements for frequency stability and phase consistency in atomic manipulation and quantum measurement applications.

[0069] The following is an example illustrating this solution, such as... Figure 1 As shown, the main laser 1 serves as the frequency reference source for Raman light, and its output light first passes sequentially through the first acousto-optic frequency shifter 3 and the frequency stabilization module 11. Specifically, the first acousto-optic frequency shifter 3 performs a single frequency shift on the output light of the main laser 1, with a shift amount of... 760MHz. The frequency-shifted laser light is introduced into the frequency stabilization module 11, which uses a modulation-transfer frequency stabilization method to lock the frequency of the main laser 1 at cesium atom 6. 2 S1 / 2, F=4 to 6 2 The atomic transition line at P3 / 2, F′=5. This frequency stabilization method ensures that the frequency stability of the main laser 1 is better than 1MHz. The first acousto-optic frequency shifter 3... The 760MHz frequency shift is used to provide the basis for single-photon detuning of the subsequently generated Raman light.

[0070] The frequency-stabilized output light of the master laser 1 is split into two paths, which are then combined with the output light of the slave laser 2 before the optical input ends of the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5, respectively. Similarly, the output light of the slave laser 2 is split into two paths, corresponding to the optical paths of the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5, respectively. By controlling the on / off states of the first optical switch 21, the second optical switch 22, the third optical switch 23, and the fourth optical switch 24, the combination of the master laser 1 and the slave laser 2 in different optical paths can be selectively changed, thereby achieving multiple Raman operating modes. Before the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5, a portion of the optical power is split from the optical path by the third beam splitter 14 and the fourth beam splitter 15, respectively, for beat frequency detection between the master laser 1 and the slave laser 2. The split beat frequency light is injected into the beat frequency detector 81, and this beat frequency electrical signal is input to the optical phase-locked loop 82 in the phase-locked module 8, and acts on the slave laser 2 through feedback to achieve phase locking of the slave laser 2. In this embodiment, the beat frequency phase-locked point is set before the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5, thereby avoiding the influence of laser pulses caused by the interruption of the acousto-optic frequency shifter on the stability of the phase-locked loop, and at the same time, the optical path after the phase-locked point is shortened as much as possible to reduce the Raman phase noise introduced by the optical path difference.

[0071] The master laser 1 and the slave laser 2 are frequency-modulated again at the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5. The frequency shift amount of both the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5 is +110MHz. The first acousto-optic frequency shifter 3... The 760MHz frequency shift, combined with the +110MHz frequency shift of the second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5, results in a blue detuning of approximately 870MHz relative to the atomic transition spectral lines in the final output Raman light. The second acousto-optic frequency shifter 4 and the third acousto-optic frequency shifter 5 are also used for pulse modulation control of the Raman light. By switching its driving signal on and off, Raman light pulses are generated with an extinction ratio greater than 30dB, a pulse delay of approximately 1µs, and rise and fall times both less than 1µs.

[0072] The Raman light output from the second acousto-optic frequency shifter 4 is coupled into the first optical fiber 6 through the first coupling head 25, and the other end of the first optical fiber 6 is connected to the first collimator 27; the Raman light output from the third acousto-optic frequency shifter 5 is coupled into the second optical fiber 7 through the second coupling head 26, and the other end of the second optical fiber 7 is connected to the second collimator 28. The two Raman beams, collimated by the first collimator 27 and the second collimator 28, are output from the system and used to induce stimulated Raman transitions in atomic groups. Based on the velocity relationship of the atomic group relative to the Raman light propagation direction and experimental parameters, multiple operating modes are achieved by controlling the on / off states of the first optical switch 21, the second optical switch 22, the third optical switch 23, and the fourth optical switch 24.

[0073] The above description is only 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 multi-mode switching stimulated Raman transition laser system, characterized in that, include: The master laser (1), the slave laser (2), the first optical switch (21), the second optical switch (22), the third optical switch (23) and the fourth optical switch (24); The main laser emitted by the main laser (1) is divided into a first main laser and a second main laser; the slave laser emitted by the slave laser (2) is divided into a first slave laser and a second slave laser. The first optical switch (21) is disposed on the propagation path of the first main laser. The first main laser is controlled by the first optical switch (21) to selectively continue propagating backward to the first beam combiner (31). The second optical switch (22) is disposed on the propagation path of the second main laser. The second main laser is controlled by the second optical switch (22) to selectively continue propagating backward to the second beam combiner (32). The third optical switch (23) is disposed on the propagation path of the first laser, and the first laser is controlled by the third optical switch (23) to selectively continue propagating backward to the first beam combiner (31); the fourth optical switch (24) is disposed on the propagation path of the second laser, and the second laser is controlled by the fourth optical switch (24) to selectively continue propagating backward to the second beam combiner (32). The switching of different working modes is achieved through the combination of switch states formed by the first optical switch (21), the second optical switch (22), the third optical switch (23) and the fourth optical switch (24).

2. The stimulated Raman transition laser system according to claim 1, characterized in that, It also includes a first beam splitter (12) coupled to the main laser (1) and a second beam splitter (13) coupled to the slave laser (2). The first beam splitter (12) is used to split the main laser into a first main laser and a second main laser; The second beam splitter (13) is used to split the laser beam into a first laser beam and a second laser beam.

3. The stimulated Raman transition laser system according to claim 1, characterized in that, It also includes a third beam splitter (14) coupled to the first beam combiner (31), a fourth beam splitter (15) coupled to the second beam combiner (32), and a phase-locked module (8) connected to the laser (2). The third beam splitter (14) is used to split the first beam combined output by the first beam combiner (31) into a first sub-beam combined and a second sub-beam combined, wherein the first sub-beam combined continues to propagate backward and the second sub-beam combined propagates to the phase-locked module (8). The fourth beam splitter (15) is used to split the second beam combined output by the second beam combiner (32) into a third sub-beam combined and a fourth sub-beam combined, wherein the third sub-beam combined continues to propagate backward and the fourth sub-beam combined propagates to the phase-locked module (8). The phase-locked module (8) is used to perform phase locking on the slave laser (2) based on the second sub-beam and the fourth sub-beam.

4. The stimulated Raman transition laser system according to claim 3, characterized in that, The phase-locked module (8) includes a beat frequency detector (81) and an optical phase-locked loop (82). The output of the beat frequency detector (81) is connected to the input of the optical phase-locked loop (82), and the output of the optical phase-locked loop (82) is connected to the laser (2). The beat frequency detector (81) is used to perform beat frequency detection on the second sub-beam and the fourth sub-beam, and the optical phase-locked loop (82) is used to perform phase locking on the slave laser (2) according to the detection result.

5. The stimulated Raman transition laser system according to claim 3, characterized in that, It also includes a second acousto-optic frequency shifter (4), a first coupling head (25), a first optical fiber (6), and a first collimator (27) coupled sequentially along the optical path; wherein, the second acousto-optic frequency shifter (4) is used to receive the first sub-beam combined light and to perform frequency shift modulation on the first sub-beam combined light.

6. The stimulated Raman transition laser system according to claim 3, characterized in that, It also includes a third acousto-optic frequency shifter (5), a second coupling head (26), a second optical fiber (7), and a second collimator (28) that are coupled sequentially along the optical path; The third acoustic-optical frequency shifter (5) is used to receive the third sub-beam combined light and to perform frequency shift modulation on the third sub-beam combined light.

7. The stimulated Raman transition laser system according to claim 1, characterized in that, It also includes a first acousto-optic frequency shifter (3) and a frequency stabilization module (11) connected to the main laser (1). The first acousto-optic frequency shifter (3) is used to receive the main laser and shift the frequency of the main laser to obtain frequency-shifted light, which continues to propagate to the frequency stabilization module (11). The frequency stabilization module (11) is used to lock the frequency of the main laser emitted by the main laser (1) using the frequency-shifted light as a reference.

8. A method of using a multi-mode switching stimulated Raman transition laser system, applied to a multi-mode switching stimulated Raman transition laser system as described in any one of claims 1 to 7, characterized in that, include: The first optical switch (21) and the third optical switch (23) are turned on, and the second optical switch (22) and the fourth optical switch (24) are turned off, so that the stimulated Raman transition laser system is in a first working mode; or, the second optical switch (22) and the fourth optical switch (24) are turned on, and the first optical switch (21) and the third optical switch (23) are turned off, so that the stimulated Raman transition laser system is in a first working mode; Control the first optical switch (21) and the fourth optical switch (24) to be turned on, and control the second optical switch (22) and the third optical switch (23) to be turned off, so that the stimulated Raman transition laser system is in the second working mode; The second optical switch (22) and the third optical switch (23) are turned on, and the first optical switch (21) and the fourth optical switch (24) are turned off, so that the stimulated Raman transition laser system is in the third working mode.

9. The method of using the stimulated Raman transition laser system according to claim 8, characterized in that, The method further includes: The output frequency of the main laser (1) is locked to a predetermined atomic transition spectrum line by the frequency stabilization module (11), and the main laser modulated by the first acousto-optic frequency shifter (3) and the frequency stabilization module (11) is used as the frequency reference to lock the phase of the slave laser (2), so that a fixed frequency difference and a stable phase relationship are generated and maintained between the lasers output by the main laser (1) and the slave laser (2). The first beam combined by the first beam combining element (31) is split into a first sub-beam combined and a second sub-beam combined by the third beam splitting element (14); the second beam combined by the second beam combining element (32) is split into a third sub-beam combined and a fourth sub-beam combined by the fourth beam splitting element (15). The first sub-beam beam is frequency-shifted and modulated by controlling the second acousto-optic frequency shifter (4); the third sub-beam beam is frequency-shifted and modulated by the third acousto-optic frequency shifter (5) to generate Raman light with a predetermined frequency configuration and timing characteristics, and output via the first collimator (27) and the second collimator (28).

10. The method of using the stimulated Raman transition laser system according to claim 9, characterized in that, The method further includes: The main laser output from the main laser (1) is introduced into the first acousto-optic frequency shifter (3) to perform frequency shift modulation on the main laser, thereby obtaining frequency-shifted light, and the frequency-shifted light is input to the frequency stabilization module (11). The frequency stabilization module (11) controls the main laser (1) based on the frequency shifting light through feedback, so that the output frequency of the main laser (1) is locked at a predetermined atomic transition spectrum line; The second sub-beam combiner and the fourth sub-beam combiner are jointly guided into the beat frequency detector (81). The beat frequency detector (81) performs beat frequency detection on the second sub-beam combiner and the fourth sub-beam combiner to generate corresponding beat frequency signals; The beat frequency signal is input to the optical phase-locked loop (82), the optical phase-locked loop (82) generates an error signal, and the error signal is fed back to the slave laser (2) to perform phase modulation and control on the slave laser (2).

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