Rydberg atom coupling laser frequency locking device and method

Abstract

The invention relates to the technical field of laser frequency locking, and discloses a Rydberg atom coupling laser frequency locking device and method. The device comprises a detection laser generation module used for emitting first detection laser to an atomic gas chamber module; the coupling laser generating module is used for emitting first coupling laser; the external modulation transfer spectrum module is used for performing phase modulation on the first coupled laser to obtain second coupled laser; the atomic gas chamber module is used for providing a reaction environment for the first detection laser and the second coupling laser, so that a modulation signal of the second coupling laser is transferred to the first detection laser to obtain the second detection laser; and the external modulation transfer spectrum module is also used for processing the second detection laser and adjusting the output frequency of the coupling laser generation module according to a processing result so as to lock the laser frequency. According to the invention, the external modulation technology is combined with the electromagnetic induction transparency effect, so that high-precision, high-stability and low-noise laser frequency locking is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser frequency locking, and particularly relates to a Rydberg atom coupled laser frequency locking device and method. BACKGROUND

[0002] Rydberg atoms refer to atoms in highly excited states, with their electrons excited to a state close to ionization. This special excited state makes Rydberg atoms have some unique physical properties, such as long lifetime, large dipole moment, strong interaction, and high sensitivity to electromagnetic fields. These properties make Rydberg atoms have wide application prospects in quantum precision measurement, quantum computing, quantum communication, and laser technology.

[0003] In recent years, the application of Rydberg atoms in laser frequency locking technology has attracted widespread attention. Laser frequency locking technology is to stabilize the frequency of a laser at a specific value through some mechanism to improve the stability and accuracy of the laser. Traditional laser frequency locking methods usually rely on optical cavities or atomic transition lines, but these methods have some limitations, such as poor stability of optical cavities and locking accuracy of atomic transition lines that may be disturbed by environmental factors.

[0004] Electromagnetically induced transparency (EIT) is a typical nonlinear optical phenomenon that suppresses the absorption of specific frequency light by atoms through quantum interference, making the originally opaque medium transparent under certain conditions. The application of EIT effect in laser frequency locking mainly reflects the use of sharp resonance peaks of EIT signals to achieve high-precision frequency reference. When the frequency of the coupling light matches the specific energy level difference of the atom, the absorption of the probe light will significantly decrease, forming a sharp EIT peak. By locking this EIT peak, high-precision laser frequency locking can be achieved. This method has the advantages of high sensitivity and high resolution, which can effectively overcome the limitations of traditional methods.

[0005] Although some research has attempted to use Rydberg atoms and EIT effect to achieve laser frequency locking, there are still some limitations in existing technology. For example, the internal modulation method used in some research introduces additional phase noise, limiting the precision and stability of laser frequency locking. In addition, the existing device is complex in structure and has low integration, which is not conducive to the promotion and use in practical applications. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a Rydberg atom coupled laser frequency locking device and method to solve the problems in the prior art.

[0007] In a first aspect, the application provides a Rydberg atom coupling laser frequency locking device, comprising a probe laser generation module, a coupling laser generation module, an external modulation transfer spectrum module, and an atomic cell module; The probe laser generation module is configured to emit first probe laser of a first frequency to the atomic cell module through a first optical path; wherein the first probe laser of the first frequency is configured to excite alkali metal atoms in the atomic cell module from a ground state to an intermediate excited state; The coupling laser generation module is configured to emit first coupling laser of a second frequency through a second optical path; wherein the first coupling laser of the second frequency is configured to excite alkali metal atoms in the atomic cell module from the intermediate excited state to a Rydberg atom state; The external modulation transfer spectrum module is configured to perform phase modulation on the first coupling laser to obtain second coupling laser, which is injected into the atomic cell module through the second optical path; The atomic cell module is configured to cause nonlinear four-wave mixing of the first probe laser and the second coupling laser, so that the modulation signal of the second coupling laser is transferred to the first probe laser, and the obtained second probe laser is emitted to the external modulation transfer spectrum module through a third optical path; The external modulation transfer spectrum module is further configured to process the second probe laser, and adjust the output frequency of the coupling laser generation module according to the processing result to realize laser frequency locking.

[0008] In a second aspect, the application provides a Rydberg atom coupling laser frequency locking method, which is realized by the Rydberg atom coupling laser frequency locking device provided in the above technical solution, and comprises the following steps: Emitting first probe laser of a first frequency to the atomic cell module; wherein the first probe laser of the first frequency is configured to excite alkali metal atoms in the atomic cell module from a ground state to an intermediate excited state; Emitting first coupling laser of a second frequency to the atomic cell module; wherein the first coupling laser of the second frequency is configured to excite alkali metal atoms in the atomic cell module from the intermediate excited state to a Rydberg atom state; Performing phase modulation on the first coupling laser before the first coupling laser enters the atomic cell module to obtain second coupling laser, which is injected into the atomic cell module; Causing nonlinear four-wave mixing of the first probe laser and the second coupling laser in the atomic cell module, so that the modulation signal of the second coupling laser is transferred to the first probe laser to obtain second probe laser; Processing the second probe laser, and adjusting the output frequency of the first coupling laser according to the processing result to realize laser frequency locking.

[0009] The beneficial effects of the present application are: the first coupled laser is phase-modulated by the external modulation transfer spectrum module, the first probe laser and the second coupled laser are provided with a reaction environment for generating nonlinear four-wave mixing by the atomic cell module, the modulation signal of the second coupled laser is transferred to the first probe laser, the first probe laser of the first frequency is used for exciting alkali metal atoms in the atomic cell module from a ground state to an intermediate excited state; the first coupled laser of the second frequency is used for exciting alkali metal atoms in the atomic cell module from the intermediate excited state to a Rydberg atomic state; that is, the present application realizes high-precision, high-stability and low-noise laser frequency locking by combining the external modulation technology with the electromagnetic induced transparency effect.

[0010] Additional aspects of the application, together with the advantages thereof over BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a structure schematic diagram of a Rydberg atom coupled laser frequency locking device shown by an exemplary embodiment of the present application; Figure 2 is a structure schematic diagram of a Rydberg atom coupled laser frequency locking device shown by another exemplary embodiment of the present application; Figure 3 is a flow chart of a Rydberg atom coupled laser frequency locking method shown by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0012] The embodiments of the present application will be described in detail hereinafter with specific reference to the drawings. It is to be noted that the following descriptions of the embodiments are other than relative to the only embodiments of the present application, but relative to a part of the embodiments of the present application. The present application can also be implemented or applied by other different specific embodiments, and the details in the present specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It is to be noted that the following embodiments and features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the present application.

[0013] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0014] Figure 1 This is a schematic diagram of a Rydberg atomic-coupled laser frequency-locking device illustrated in an exemplary embodiment of this application. Figure 1 As shown, in an exemplary embodiment, the Rydberg atom-coupled laser frequency-locking device may include a probe laser generation module 100, a coupling laser generation module 200, an atomic gas cell module 300, and an external modulation transfer spectrum module 400, which are described in detail below: The detection laser generating module 100 is used to emit a first detection laser of a first frequency to the atomic gas cell module 300 through a first optical path; wherein, the first detection laser of the first frequency is used to excite alkali metal atoms in the atomic gas cell module from the ground state to an intermediate excited state; The coupled laser generating module 200 is used to emit a first coupled laser of a second frequency through a second optical path; wherein, the first coupled laser of the second frequency is used to excite alkali metal atoms in the atomic gas chamber module from the intermediate excited state to the Rydberg atomic state; The external modulation transfer spectrum module 400 is used to perform phase modulation on the first coupled laser, and the resulting second coupled laser is injected into the atomic gas cell module 300 through the second optical path. The atomic gas cell module 300 is used to perform nonlinear four-wave mixing of the first probe laser and the second coupling laser, so that the modulation signal of the second coupling laser is transferred to the first probe laser, and the resulting second probe laser is emitted to the external modulation transfer spectrum module 400 through the third optical path. The external modulation transfer spectrum module 400 is also used to process the second probe laser and adjust the output frequency of the coupled laser generator module 200 according to the processing result to achieve laser frequency locking.

[0015] In the embodiment of the present application, the probe laser corresponds to the D2 line of alkali metal atoms, and the frequency of the probe laser is 852 nm taking Cs atoms as an example. The probe laser can excite the alkali metal atoms from the ground state 6S1 / 2 to the intermediate excited state 6P3 / 2. The coupling laser further excites the atoms to the Rydberg state, for example, the coupling laser of 509.394 nm can further excite the Cs atoms from the intermediate state 6P3 / 2 to the state 53D5 / 2. When the frequency of the coupling laser is linearly scanned near 509.394 nm, a sharp peak signal corresponding to the electromagnetically induced transparency signal can be observed in the probe signal.

[0016] In the embodiment of the present application, the first coupling laser is phase-modulated by the external modulation transfer spectrum module 400, and the first probe laser and the second coupling laser are provided with a reaction environment by the atomic cell module 300, so that the modulation signal of the second coupling laser is transferred to the first probe laser. The first probe laser of the first frequency is used to excite the alkali metal atoms in the atomic cell module 300 from the ground state to the intermediate excited state; the first coupling laser of the second frequency is used to excite the alkali metal atoms in the atomic cell module 300 from the intermediate excited state to the Rydberg state. That is, the present application realizes the laser frequency locking with high precision, high stability and low noise by combining the external modulation technology with the electromagnetically induced transparency effect. The device structure is compact, easy to integrate and expand, and suitable for quantum precision measurement, optical communication and spectral analysis fields. The Rydberg atom coupling laser frequency locking device provided in the embodiment of the present application can be applied to the EIT effect under the fiber-coupled cell and the EIT effect under the spatial light.

[0017] Figure 2 is a schematic structural diagram of a Rydberg atom coupling laser frequency locking device shown in another exemplary embodiment of the present application. As shown in Figure 2 , in an exemplary embodiment, the atomic cell module 300 of the Rydberg atom coupling laser frequency locking device can include three micro-collimators, an atomic cell 3 and a dichroic prism 4.

[0018] One end of the atomic cell 300 is fixed with the first micro-collimator 2, and the other end is fixed with the dichroic prism 4. The second micro-collimator 10 is fixed to one end of the dichroic prism 4 facing the second light path, and is connected to the second light path through the second micro-collimator 10. The third micro-collimator 5 is fixed to one end of the dichroic prism 4 facing the third light path, and is connected to the third light path through the third micro-collimator 5. The dichroic prism 4 is used to realize the transmission of the probe light and the reflection of the coupling light. The atomic cell 3 is used to provide the first probe laser and the second coupling laser with a reaction environment for nonlinear four-wave mixing, so that the modulation signal of the second coupling laser is transferred to the first probe laser, and the obtained second probe laser is emitted to the external modulation transfer spectrum module 400 through the third light path.

[0019] In the embodiment of the present application, the three micro-collimators are implemented by Clens lenses or Llens lenses. The alkali metal gas atoms in the atomic cell are one of potassium atoms, rubidium atoms and cesium atoms. The first frequency of the first probe laser is a D2 absorption line of the potassium atoms, the rubidium atoms or the cesium atoms. The atomic cell can be in a cylindrical shape, a cuboid shape or other special shapes. The first optical path, the second optical path and the third optical path adopt single-mode polarization maintaining optical fibers or single-mode non-polarization maintaining optical fibers.

[0020] In the embodiment of the present application, the first micro-fiber collimator 2, the second micro-fiber collimator 5 and the third micro-fiber collimator 10 are composed of cylindrical lenses clens, connected with optical fibers through capillary glass tubes to realize the collimation of the light emitted by the optical fibers. During the process of bonding the three micro-collimators and the bichromatic prism 4 with the atomic cell 3, it is ensured that the light of the three micro-collimators can converge to a point, and the light emitted by the first micro-collimator 2 and the third micro-collimator 5 can coincide. The laser emitted by the probe laser 1 is coupled into a polarization maintaining optical fiber and connected to the micro-collimator 2 through polarization maintaining fusion.

[0021] As shown in FIG. 1, Figure 2 In an exemplary embodiment, the Rydberg atom coupling laser frequency locking device can include a phase modulation module 401 and a feedback control module 402.

[0022] The phase modulation module 401 is arranged on the second optical path and is used for phase modulating the first coupling laser according to a preset radio frequency signal to obtain the second coupling laser which is injected into the atomic cell module. The feedback control module 402 is electrically connected with the phase modulation module 401 and the coupling laser generation module 200, respectively, and is used for processing the second probe laser according to the preset radio frequency signal, adjusting the output frequency of the coupling laser generation module according to the processing result, and realizing the locking of the laser frequency.

[0023] In the embodiment of the present application, the phase modulation module 401 is used to introduce a modulation signal with a specific frequency and amplitude to phase modulate the first coupling laser, which effectively avoids the influence of the modulation noise on the laser frequency locking. The alkali metal atoms in the atomic cell generate an EIT effect under the action of the probe laser and the coupling laser, and emit the reacted probe light. The feedback control module processes the received second probe light and adjusts the output frequency of the coupling laser according to the processing result, thereby realizing the locking of the laser frequency.

[0024] As shown in FIG. 1, Figure 2As shown, in an exemplary embodiment, the phase modulation module 401 of the Rydberg atomic coupling laser frequency locking device may include a radio frequency signal generator 7 and an electro-optic modulator 8. The radio frequency signal generator 7 is electrically connected to the electro-optic modulator 8 and is used to provide the electro-optic modulator 8 with a preset radio frequency signal of preset frequency and amplitude; the electro-optic modulator 8 is disposed in the second optical path and is used to perform phase modulation on the first coupled laser according to the preset radio frequency signal, so that the resulting second coupled laser is injected into the atomic gas cell module 300.

[0025] In this embodiment of the invention, one end of the electro-optic modulator 8 is connected to the second miniature collimator 10 by polarization-maintaining fusion splicing, and the other end is coupled to the laser emitted from the coupled laser 9 through a polarization-maintaining fiber.

[0026] This invention utilizes external modulation transfer spectroscopy technology to lock the laser frequency. Specifically, the radio frequency signal generator 7 generates a radio frequency signal with a specific frequency and amplitude, which is then used by an external modulator (electro-optic modulator 8) to phase modulate the first coupled laser. Therefore, the frequency components of the second coupled laser include the carrier wave. and side strip , This is the modulation frequency. Generally, higher-order sidebands are ignored, and only the first-order sidebands are considered. The first probe laser and the second coupling laser interact with alkali metal atoms in the atomic gas cell 3. The two beams undergo nonlinear four-wave mixing in the atomic gas cell, causing the modulation signal on the second coupling laser to be transferred to the first probe laser.

[0027] like Figure 2 As shown, in an exemplary embodiment, the feedback control module 401 of the Rydberg atomic-coupled laser frequency locking device includes a photodetector 6, a frequency discrimination signal extraction module, and a PID control circuit 14.

[0028] The photodetector 6 is used to perform photoelectric conversion on the detected second detection laser; the frequency discrimination signal extraction module is electrically connected to the photodetector 6 and the radio frequency signal generator 7 respectively, and is used to extract the coupling laser frequency discrimination signal of the second detection laser according to the preset radio frequency signal; the PID control circuit 14 is electrically connected to the frequency discrimination signal extraction module and the coupling laser generation module 200 respectively, and is used to adjust the output frequency of the coupling laser generation module according to the coupling laser frequency discrimination signal to achieve laser frequency locking.

[0029] like Figure 2As shown in an exemplary embodiment, the frequency discrimination signal extraction module of the Rydberg atomic coupling laser frequency locking device includes a phase shifter 11, a mixer 12, and a low-pass filter 13. The phase shifter 11 is electrically connected to the radio frequency signal generator 7 and the mixer 12, respectively, and is used to perform phase modulation or phase compensation on a preset radio frequency signal; the mixer 12 is electrically connected to the photodetector 6 and the low-pass filter 13, respectively, and is used to mix the phase-shifted preset radio frequency signal with a second detection laser to obtain a third detection laser; the low-pass filter 13 is electrically connected to the PID control circuit 14, and is used to perform low-pass filtering on the third detection laser and send the filtered coupled laser frequency discrimination signal to the PID control circuit 14.

[0030] In this embodiment of the invention, the sinusoidal signal generated by the radio frequency signal generator 7 is connected to the phase shifter 11 and the electro-optic modulator 8 via wires, respectively. The output signal of the phase shifter 11 is then transmitted to the mixer 12 via wires. The probe light from the probe laser 1, passing through the atomic gas cell 3 and the dichroic prism 4, is coupled to the miniature collimator 5 and received by the fiber optic photodetector 6. The spectral signal is converted into an electrical signal by the amplification circuit of the photodetector 6 and sent to the mixer 12 for mixing with the output signal of the phase shifter 11. The phase shifter 11 is used to change the phase of the radio frequency signal to achieve phase modulation or phase compensation; the mixer 12 is used to mix the probe light signal with the radio frequency signal to generate new frequency components for down-conversion processing of the signal; the low-pass filter 13 is used to filter out high-frequency noise components and retain low-frequency signals to obtain the coupled laser frequency discrimination signal. The frequency discrimination signal is transmitted to the PID control circuit 14 via wires. The PID control circuit 14 is used to perform proportional, integral, and derivative control based on the signal output by the low-pass filter to adjust the output frequency of the coupled laser 9 and achieve laser frequency locking. This locking method not only improves the accuracy of frequency locking but also significantly reduces the system's noise level, ensuring long-term stability of the laser frequency. Furthermore, integrating the Rydberg atomic laser with optical components and detectors onto a compact fiber optic platform greatly reduces the size and weight of the device, improving its portability and maintainability.

[0031] like Figure 2 As shown, in an exemplary embodiment, the Rydberg atomic-coupled laser frequency-locking device includes a probe laser 1, a first micro-collimator 2, an atomic gas cell 3, a two-color prism 4, a second micro-collimator 10, a third micro-collimator 5, a photodetector 6, a radio frequency signal generator 7, an electro-optic modulator EOM 8, a coupling laser 9, a phase shifter 11, a mixer 12, a low-pass filter 14, and a PID control circuit 14.

[0032] In the embodiment of the present application, the first probe laser emitted by the probe laser 1 is coupled into a polarization maintaining optical fiber, transmitted through the polarization maintaining optical fiber to the micro-collimator 2, and enters the atomic cell 3 to be absorbed by the alkali metal atoms. The alkali metal atoms are excited to an intermediate excited state by the first probe laser. After the remaining probe light is transmitted through the atomic cell 3 and then through the dichroic prism 4, it is coupled into the micro-collimator 5. Through the transmission of the single-mode optical fiber, it enters the fiber-optic photoelectric detector 6.

[0033] The radio frequency signal generator 7 outputs a sine wave signal of a specific signal frequency and amplitude to the electro-optical modulator 8. The coupling light emitted by the coupling laser 9 is transmitted through the polarization maintaining optical fiber to the electro-optical modulator 8, then modulated in phase and transmitted to the micro-collimator 10. After being reflected by the dichroic prism 4, it enters the atomic cell 3 to be absorbed by the alkali metal atoms. The alkali metal atoms are excited from the intermediate state to the Rydberg state. Nonlinear four-wave mixing occurs between the two beams in the atomic cell 3, causing the modulation signal on the coupling light to be transferred to the probe light.

[0034] The electrical signal converted by the photoelectric detector 6 is mixed with the signal obtained after the sine wave signal output by the radio frequency signal generator 7 passes through the phase shifter 11 in the mixer 12. Then, the high-frequency part and the direct current signal are filtered out by the low-pass filter 13 to obtain the frequency discrimination signal of the cesium atom D2 line. The frequency discrimination signal obtained is input to the PID control circuit 14 to drive the piezoelectric ceramic of the coupling laser 9. Without scanning the coupling light, the frequency discrimination signal realizes external modulation frequency stabilization. The output end of the external modulation detection does not introduce the modulation signal, so the modulation signal introduced by the external modulation frequency stabilization does not affect the detection output end.

[0035] The embodiment of the present application aims to realize high-precision, high-stability and low-noise laser frequency locking through the external modulation technology combined with the electromagnetic induced transparency effect. The device is particularly suitable for application scenarios that require high-precision laser frequency locking, such as quantum precision measurement, optical communication and spectral analysis. Through the radio frequency signal generator 7, a specific frequency and amplitude modulation signal is introduced to the electro-optical modulator 8 to modulate the phase of the coupling light, effectively avoiding the influence of modulation noise on laser frequency locking. The atomic cell 3 is used to realize the interaction of the probe light and the coupling light with the Rydberg atoms to produce the EIT effect. The feedback control system includes the photoelectric detector 6, the phase shifter 11, the mixer 12, the low-pass filter 13 and the PID control circuit 14. The photoelectric detector 6 detects the optical signal and converts it into an electrical signal. The phase shifter 11, the mixer 12, the low-pass filter 13 and the PID control circuit 14 are used to process the signal output by the detector and adjust the output frequency of the coupling laser according to the processing result, realizing the locking of the laser frequency.

[0036] The device can realize high-precision laser frequency locking through the external modulation transfer spectroscopy technology. Second, the use of the external modulator effectively avoids the influence of modulation noise on laser frequency locking, significantly reducing the noise level of the system. In addition, the device uses a fiber transmission system and a feedback control system to ensure the long-term stability of the laser frequency. The device structure is compact, easy to integrate and expand, and suitable for various application scenarios. The use of the radio frequency signal generator and the PID control circuit allows the modulation frequency and amplitude to be flexibly adjusted as needed, adapting to different experimental and application requirements. Through the above design and implementation steps, the device of the present application can realize high-precision, high-stability and low-noise laser frequency locking, providing strong technical support for related research and application.

[0037] Figure 3 is a flow chart of a method for coupling laser frequency locking of a Rydberg atom according to an example embodiment of the present application. As shown in Figure 3 , in an example embodiment, the method for coupling laser frequency locking of a Rydberg atom can be implemented by the device for coupling laser frequency locking of a Rydberg atom provided by any of the above embodiments. The method includes the following steps, which are described in detail as follows: S1, emitting a first probe laser of a first frequency to the atomic cell module; wherein the first probe laser of the first frequency is used to excite alkali metal atoms in the atomic cell module from a ground state to an intermediate excited state; S2, emitting a first coupling laser of a second frequency to the atomic cell module; wherein the first coupling laser of the second frequency is used to excite alkali metal atoms in the atomic cell module from the intermediate excited state to a Rydberg atom state; S3, phase modulating the first coupling laser before it enters the atomic cell module to obtain a second coupling laser which is injected into the atomic cell module; S4, the first probe laser and the second coupling laser undergo nonlinear four-wave mixing in the atomic cell module, causing the modulation signal of the second coupling laser to be transferred to the first probe laser to obtain a second probe laser; S5, processing the second probe laser and adjusting the output frequency of the first coupling laser according to the processing result to realize laser frequency locking.

[0038] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific implementation process of the method steps described above can refer to the corresponding process in the foregoing device embodiment, which will not be described here.

[0039] In several embodiments provided in the present application, it should be understood that the disclosed apparatus and method can be implemented by other manners. For example, the apparatus embodiments described above are merely illustrative, for example, the division of units is merely a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed.

[0040] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they can be located in one place or distributed on a plurality of network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment of the present application.

[0041] In addition, the functional units in each embodiment of the present application can be integrated in one processing unit, or each unit can be physically present separately, or two or more units can be integrated in one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0042] If the integrated unit is realized in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the part that contributes to the prior art, or all or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the embodiments of the present application. The foregoing storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk, and various program code storage media.

[0043] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A Rydberg atomic-coupled laser frequency-locking device, characterized in that, It includes a detection laser generation module, a coupling laser generation module, an external modulation transfer spectroscopy module, and an atomic gas cell module; The detection laser generating module is used to emit a first detection laser of a first frequency to the atomic gas cell module through a first optical path; wherein, the first detection laser of the first frequency is used to excite alkali metal atoms in the atomic gas cell module from the ground state to an intermediate excited state; The coupled laser generating module is used to emit a first coupled laser of a second frequency through a second optical path; wherein, the first coupled laser of the second frequency is used to excite alkali metal atoms in the atomic gas chamber module from an intermediate excited state to a Rydberg atomic state; The external modulation transfer spectroscopy module is used to perform phase modulation on the first coupled laser, and the resulting second coupled laser is injected into the atomic gas cell module through the second optical path; The atomic gas cell module is used to perform nonlinear four-wave mixing between the first probe laser and the second coupling laser, so that the modulation signal of the second coupling laser is transferred to the first probe laser, and the resulting second probe laser is emitted to the external modulation transfer spectrum module through the third optical path; The external modulation transfer spectroscopy module is also used to process the second detection laser and adjust the output frequency of the coupled laser generation module according to the processing result to achieve laser frequency locking.

2. The Rydberg atomic-coupled laser frequency-locking device according to claim 1, characterized in that, The atomic gas cell module includes three miniature collimators, an atomic gas cell, and a dichroic prism; One end of the atomic gas cell is fixed to the first micro collimator, and the other end is fixed to the dichroic prism; The dichroic prism has a second micro-collimator fixed to one end facing the second optical path, and is connected to the second optical path through the second micro-collimator; the dichroic prism has a third micro-collimator fixed to one end facing the third optical path, and is connected to the third optical path through the third micro-collimator; the dichroic prism is used to realize the transmission of probe light and the reflection of coupled light; The atomic gas chamber is used to provide a reaction environment for nonlinear four-wave mixing for the first probe laser and the second coupling laser, so that the modulation signal of the second coupling laser is transferred to the first probe laser, and the resulting second probe laser is emitted to the external modulation transfer spectrum module through the third optical path.

3. The Rydberg atomic-coupled laser frequency-locking device according to claim 2, characterized in that, The three miniature collimators are implemented using Clens or Lens lenses.

4. The Rydberg atomic-coupled laser frequency-locking device according to claim 2, characterized in that, The alkali metal gas atoms in the atomic chamber are one of potassium atoms, rubidium atoms, and cesium atoms; the first frequency of the first detection laser is the D2 absorption line of potassium atoms, rubidium atoms, or cesium atoms.

5. The Rydberg atomic-coupled laser frequency-locking device according to any one of claims 1 to 4, characterized in that, The external modulation transfer spectroscopy module includes a phase modulation module and a feedback control module; The phase modulation module is disposed on the second optical path and is used to perform phase modulation on the first coupled laser according to a preset radio frequency signal, so that the resulting second coupled laser is injected into the atomic gas cell module. The feedback control module is electrically connected to the phase modulation module and the coupled laser generator module, respectively, and is used to process the second detection laser according to the preset radio frequency signal, and adjust the output frequency of the coupled laser generator module according to the processing result to achieve laser frequency locking.

6. The Rydberg atomic-coupled laser frequency-locking device according to claim 5, characterized in that, The phase modulation module includes a radio frequency signal generator and an electro-optic modulator; The radio frequency signal generator is electrically connected to the electro-optic modulator and is used to provide the electro-optic modulator with a preset radio frequency signal of preset frequency and amplitude. The electro-optic modulator is disposed on the second optical path and is used to perform phase modulation on the first coupled laser according to the preset radio frequency signal, so that the resulting second coupled laser is injected into the atomic gas cell module.

7. The Rydberg atomic-coupled laser frequency-locking device according to claim 6, characterized in that, The feedback control module includes a photodetector, a frequency discrimination signal extraction module, and a PID control circuit. The photodetector is used to perform photoelectric conversion on the detected second detection laser. The frequency discrimination signal extraction module is electrically connected to the photodetector and the radio frequency signal generator, respectively, and is used to extract the coupled laser frequency discrimination signal of the second detection laser according to the preset radio frequency signal; The PID control circuit is electrically connected to the frequency discrimination signal extraction module and the coupled laser generation module, respectively, and is used to adjust the output frequency of the coupled laser generation module according to the coupled laser frequency discrimination signal to achieve laser frequency locking.

8. The Rydberg atomic-coupled laser frequency-locking device according to claim 7, characterized in that, The frequency discrimination signal extraction module includes a phase shifter, a mixer, and a low-pass filter; The phase shifter is electrically connected to the radio frequency signal generator and the mixer respectively, and is used to perform phase modulation or phase compensation on the preset radio frequency signal; The mixer is electrically connected to the photodetector and the low-pass filter respectively, and is used to mix the phase-shifted preset radio frequency signal with the second detection laser to obtain the third detection laser. The low-pass filter is electrically connected to the PID control circuit and is used to perform low-pass filtering on the third detection laser, and send the filtered coupled laser frequency discrimination signal to the PID control circuit.

9. The Rydberg atomic-coupled laser frequency-locking device according to any one of claims 1 to 4, characterized in that, The first, second, and third optical paths use single-mode polarization-maintaining fiber or single-mode non-polarization-maintaining fiber.

10. A Rydberg atomic-coupled laser frequency-locking method, characterized in that, This is achieved using the Rydberg atomic-coupled laser frequency-locking device according to any one of claims 1 to 9, comprising the following steps: A first probe laser of a first frequency is emitted toward the atomic gas chamber module; wherein, the first probe laser of the first frequency is used to excite alkali metal atoms in the atomic gas chamber module from the ground state to an intermediate excited state; A first coupling laser of a second frequency is emitted into the atomic gas chamber module; wherein, the first coupling laser of the second frequency is used to excite alkali metal atoms in the atomic gas chamber module from an intermediate excited state to a Rydberg atomic state; Before the first coupled laser enters the atomic gas chamber module, the first coupled laser is phase-modulated, and the resulting second coupled laser enters the atomic gas chamber module. The first probe laser and the second coupling laser undergo nonlinear four-wave mixing in the atomic gas cell module, causing the modulation signal of the second coupling laser to be transferred to the first probe laser, thus obtaining the second probe laser; The second detection laser is processed, and the output frequency of the first coupling laser is adjusted according to the processing result to achieve laser frequency locking.

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