Frequency stabilization device, frequency stabilization method, sensor device and receiver for Rydberg atomic receiver

Abstract

The present invention relates to the fields of quantum sensing and quantum precision measurement, and specifically proposes a frequency stabilization device, frequency stabilization method, sensing device, and receiver for a Rydberg atom receiver. The frequency stabilization device includes a narrow-linewidth semiconductor laser 1, a narrow-linewidth semiconductor laser controller 2, a single-frequency fiber laser 16, a single-frequency fiber laser controller 15, a photodetector 12, a frequency stabilization integrated circuit 13, a DC bias device 14, a frequency stabilization integrated circuit 22, an alkali metal atom gas chamber 8, a photodetector 21, and an optical path component. The frequency stabilization device of the present invention has a simple structure, eliminating the need for complex optical and circuit systems. It can simultaneously lock the frequencies of two Rydberg lasers using a single bubble and perform microwave field sensing and detection using a parallel plate waveguide fiber integrated probe. The receiver is compact and highly portable.

Description

Technical Field

[0001] The present invention relates to the fields of quantum sensing and quantum precision measurement, and in particular to a frequency stabilization device, a frequency stabilization method, a sensing device and a receiver for a Rydberg atom receiver. Background Art

[0002] Quantum sensing technology, particularly electric field sensors based on Rydberg atoms, has attracted attention due to its potential advantages in measuring fields, forces, and time. Compared to traditional sensors, these sensors offer different sensing modalities, higher sensitivity, and the potential to achieve significant improvements in reducing size, weight, power, and cost. However, the practicality and portability of quantum sensors remain a challenge, as many technologies are still in the early stages of development. To achieve the transition of quantum sensors from the laboratory to practical applications, new technologies and sensor designs need to be developed to accelerate this process.

[0003] Rydberg atom electric field sensors have attracted considerable attention due to their broadband spectral coverage and high accuracy and precision compared to conventional antenna receivers. While substantial progress has been made in reducing the size, weight, power, and cost of Rydberg atom sensor heads, simplifying and miniaturizing the sensor's supporting lasers and electronics is crucial to enabling the technology's application outside the laboratory.

[0004] Existing laser frequency stabilization techniques for exciting non-ground-state atomic transitions are often limited by the need for large, heavy, high-power, and costly optical cavities and electronics, or by the use of significant optical power solely for frequency stabilization. These techniques are often costly, sensitive to vibrations and temperature variations, or reduce the available power in the sensor head. Summary of the Invention

[0005] In view of this, the present invention proposes a miniaturized Rydberg atom receiver with a simple structure, which does not require a complex optical path system and circuit system. It can realize the locking of two Rydberg lasers simultaneously with a single bubble and realize sensing with a parallel plate waveguide fiber integrated probe. The receiver is miniaturized and portable.

[0006] To achieve the above-mentioned objectives, in a first aspect, the present invention provides a frequency stabilization device for a Rydberg atomic receiver, comprising a narrow-linewidth semiconductor laser 1, a narrow-linewidth semiconductor laser controller 2, a single-frequency fiber laser 16, a single-frequency fiber laser controller 15, a photodetector 12, a frequency stabilization integrated circuit 13, a DC bias device 14, a frequency stabilization integrated circuit 22, an alkali metal atom gas cell 8, a photodetector 21, and an optical path component; wherein,

[0007] The laser signal emitted by the narrow-linewidth semiconductor laser 1 is divided into four beams by the optical path component, two of which are mutually overlapping at a first position in the alkali metal atom gas chamber 8. The laser signal is collected by the photodetector 12 and input into the frequency stabilization integrated circuit 13. The frequency stabilization integrated circuit 13 is connected to the DC bias device 14, and the output modulation signal is input into the narrow-linewidth semiconductor laser controller 2. The narrow-linewidth semiconductor laser controller 2 is connected to the narrow-linewidth semiconductor laser 1 and is used to control the frequency of the narrow-linewidth semiconductor laser 1.

[0008] The single-frequency fiber laser 16 emits two laser signals, one of which coincides with one of the remaining two laser signals emitted by the narrow-linewidth semiconductor laser 1 after passing through the optical path component at a second position in the alkali metal atom gas chamber 8. After being collected by the photodetector 21, the signals are input into the frequency stabilization integrated circuit 22. The frequency stabilization integrated circuit 22 is connected to the single-frequency fiber laser controller 15 and the DC bias device 14. The frequency stabilization integrated circuit 22 is connected to the single-frequency fiber laser controller 15. The single-frequency fiber laser controller 15 is connected to the single-frequency fiber laser 16 for controlling the frequency of the single-frequency fiber laser 16.

[0009] Furthermore, the optical path components include a half-wave plate 3, a polarization beam splitter prism 4, a polarization beam splitter prism 5, a half-wave plate 6, a polarization beam splitter prism 7, a polarization beam splitter prism 9, a reflector 10, a reflector 11, a dichroic mirror 19, a reflector 20, a reflector 23, and an attenuation plate 24;

[0010] The first optical path of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the half-glass 3, one end of the polarization beam splitter prism 4, one end of the polarization beam splitter prism 5, the half-glass 6, one end of the polarization beam splitter prism 7, the reflector 10, the reflector 11, and one end of the polarization beam splitter 9 and is reflected into the first position of the alkali metal atom gas chamber 8;

[0011] The second optical path of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the other end of the polarization beam splitter prism 7 and is directly incident on the alkali metal atom gas chamber 8, where it overlaps with the first optical path at the first position, and then passes through the other end of the polarization beam splitter 9 and is incident on the photodetector 12.

[0012] The third beam of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the other end of the polarization beam splitter prism 5, the reflector 23, and the attenuation plate 24, and is incident on the second position of the alkali metal atom gas cell 8. After being reflected by the dichroic mirror 19, the reflected light is incident on the photodetector 21 through the reflector 20.

[0013] The fourth optical path of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the other end of the polarization beam splitter prism 4 and is directly emitted for electric field sensing measurement;

[0014] The fifth beam of laser signal emitted by the single-frequency fiber laser 16 passes through the dichroic mirror and enters the second position of the alkali atomic absorption gas chamber 8;

[0015] The sixth optical path of the laser signal emitted by the single-frequency fiber laser 16 is directly emitted for electric field sensing measurement.

[0016] Furthermore, the optical path assembly also includes a reflector 17 and a reflector 18, which are sequentially arranged between the single-frequency fiber laser 16 and the dichroic mirror 9 to adjust the direction of the optical path and direct the fifth optical path to the second position of the alkali atomic absorption chamber 8.

[0017] Furthermore, the frequency stabilizing integrated circuit 13 and the frequency stabilizing integrated circuit 22 are respectively equipped with an oscilloscope, a mixer, a low-pass filter, a proportional-integral-differential circuit and a waveform generator.

[0018] The mixer is used for mixing and demodulating signals.

[0019] The low-pass filter is used for filtering to obtain a dispersion differential error signal.

[0020] The waveform generator is used to provide a modulation signal for the laser, input a demodulation signal into the mixer, and provide a sweep frequency signal for the laser.

[0021] The proportional-integral-differential circuit is used to control the correction signal to achieve frequency stabilization.

[0022] In a second aspect, the present invention provides a frequency stabilization method for a Rydberg atomic receiver. According to the frequency stabilization device described above, a single alkali atomic absorption cell is used to achieve frequency stabilization of two lasers.

[0023] In a third aspect, the present invention provides a sensing device for a Rydberg atom receiver, comprising a parallel waveguide 201, an alkali metal atom gas chamber 203, an optical fiber 202, an optical fiber 204, a detection optical path, a coupling optical path, a coaxial cable, and a speaker;

[0024] The alkali metal atom gas chamber 203 is embedded in the parallel waveguide 201, the coaxial cable is used to feed the local oscillator field of the microwave source, and the horn is used to input the signal field of the microwave source;

[0025] The detection light path is used to access the fourth light path described in claim 2 and input it into the optical fiber 202 as a detection light;

[0026] The coupling optical path is used to access the sixth optical path described in claim 2 and input it into the optical fiber 204 as coupling light.

[0027] Furthermore, the path of the detection light path is as follows: the detection light is incident on the coupling head 30 through the optical fiber, hits the coupling head 34 through the reflector 33, is connected to the optical fiber 202, passes through the alkali metal atom gas chamber 203, and then is connected to the coupling head 29 through the optical fiber 204, and hits the detector 32 through the dichroic mirror 28 and the reflector 31.

[0028] Furthermore, the path of the coupling light path is as follows: the coupling light is connected to the optical fiber coupling head 25 through the optical fiber, and then enters the coupling head 29 through the reflector 26 , the reflector 27 , and the dichroic mirror 28 , and then is connected to the optical fiber 204 .

[0029] In a fourth aspect, the present invention further provides a Rydberg atomic receiver, comprising the frequency stabilization device described above, the detection device described above, an oscilloscope and a host computer; the oscilloscope is connected to the detection device, and the host computer is connected to the frequency stabilization device.

[0030] Furthermore, the host computer is wirelessly connected to the frequency stabilizing device.

[0031] The beneficial technical effects of the present invention are:

[0032] 1. The present invention achieves frequency locking of a narrow-linewidth semiconductor laser and a single-frequency fiber laser through an internal modulation method. It does not require multiple alkali metal atom gas cells or additional optical devices such as electro-optic modulators. It can achieve locking and frequency stabilization of the two lasers by relying solely on a single alkali metal atom gas cell and circuit.

[0033] 2. The present invention does not require external modulation of the detection light field, and uses a single atomic bubble for locking and sensing operations.

[0034] 3. The present invention eliminates the need to add bulky equipment traditionally used for laser locking, while providing improved portability and robustness of the sensor.

[0035] 4 The present invention does not require additional light splitting for the electromagnetically induced transparent module. Other spectroscopy techniques must use a large portion of the laser power for locking (hundreds of milliwatts in the case of Rydberg atom excitation frequencies), but the technology of the present invention uses all the control laser power available in the sensor head and only uses a small part of the detection band for locking, and the rest is used for sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0037] Figure 1 A schematic diagram of a frequency stabilization device for a Rydberg atomic receiver according to the present invention;

[0038] Figure 2 A schematic diagram of a sensing device for a Rydberg atomic receiver according to the present invention;

[0039] Figure 3 The figure is a schematic structural diagram of a parallel plate waveguide probe for a Rydberg atom receiver according to the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] It should be noted that, unless there is a conflict, the various features of the embodiments of the present invention may be combined with each other and are all within the scope of protection of the present invention. In addition, although the functional modules are divided in the device schematics and the logical order is shown in the flow charts, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flow charts. Furthermore, the terms "first," "second," "third," etc. used in the present invention do not limit the data or execution order, but only distinguish between identical or similar items with substantially the same functions and effects.

[0042] refer to Figure 1 The present invention provides a frequency stabilization device for a Rydberg atomic receiver, comprising a narrow-linewidth semiconductor laser 1, a narrow-linewidth semiconductor laser controller 2, a single-frequency fiber laser 16, a single-frequency fiber laser controller 15, a photodetector 12, a frequency stabilization integrated circuit 13, a DC bias device 14, a frequency stabilization integrated circuit 22, an alkali metal atom gas cell 8, a photodetector 21, and an optical path component; wherein,

[0043] The laser signal emitted by the narrow-linewidth semiconductor laser 1 is divided into four beams by the optical path component, two of which are mutually overlapping at a first position in the alkali metal atom gas chamber 8. The laser signal is collected by the photodetector 12 and input into the frequency stabilization integrated circuit 13. The frequency stabilization integrated circuit 13 is connected to the DC bias device 14, and the output modulation signal is input into the narrow-linewidth semiconductor laser controller 2. The narrow-linewidth semiconductor laser controller 2 is connected to the narrow-linewidth semiconductor laser 1 and is used to control the frequency of the narrow-linewidth semiconductor laser 1.

[0044] The single-frequency fiber laser 16 emits two laser signals, one of which coincides with one of the remaining two laser signals emitted by the narrow-linewidth semiconductor laser 1 after passing through the optical path component at a second position in the alkali metal atom gas chamber 8. After being collected by the photodetector 21, the signals are input into the frequency stabilization integrated circuit 22. The frequency stabilization integrated circuit 22 is connected to the single-frequency fiber laser controller 15 and the DC bias device 14. The frequency stabilization integrated circuit 22 is connected to the single-frequency fiber laser controller 15. The single-frequency fiber laser controller 15 is connected to the single-frequency fiber laser 16 for controlling the frequency of the single-frequency fiber laser 16.

[0045] Furthermore, the optical path components include a half-wave plate 3, a polarization beam splitter prism 4, a polarization beam splitter prism 5, a half-wave plate 6, a polarization beam splitter prism 7, a polarization beam splitter prism 9, a reflector 10, a reflector 11, a dichroic mirror 19, a reflector 20, a reflector 23, and an attenuation plate 24;

[0046] The first optical path of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the half-glass 3, one end of the polarization beam splitter prism 4, one end of the polarization beam splitter prism 5, the half-glass 6, one end of the polarization beam splitter prism 7, the reflector 10, the reflector 11, and one end of the polarization beam splitter 9 and is reflected into the first position of the alkali metal atom gas chamber 8;

[0047] The second optical path of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the other end of the polarization beam splitter prism 7 and is directly incident on the alkali metal atom gas chamber 8, where it overlaps with the first optical path at the first position, and then passes through the other end of the polarization beam splitter 9 and is incident on the photodetector 12.

[0048] The third beam of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the other end of the polarization beam splitter prism 5, the reflector 23, and the attenuation plate 24, and is incident on the second position of the alkali metal atom gas cell 8. After being reflected by the dichroic mirror 19, the reflected light is incident on the photodetector 21 through the reflector 20.

[0049] The fourth optical path of the laser signal emitted by the narrow linewidth semiconductor laser 1 passes through the other end of the polarization beam splitter prism 4 and is directly emitted for electric field sensing measurement;

[0050] The fifth beam of laser signal emitted by the single-frequency fiber laser 16 passes through the dichroic mirror and enters the second position of the alkali atomic absorption gas chamber 8;

[0051] The sixth optical path of the laser signal emitted by the single-frequency fiber laser 16 is directly emitted for electric field sensing measurement.

[0052] Furthermore, the optical path assembly also includes a reflector 17 and a reflector 18, which are sequentially arranged between the single-frequency fiber laser 16 and the dichroic mirror 9 to adjust the direction of the optical path and direct the fifth optical path to the second position of the alkali atomic absorption chamber 8.

[0053] Furthermore, the frequency stabilizing integrated circuit 13 and the frequency stabilizing integrated circuit 22 are respectively equipped with an oscilloscope, a mixer, a low-pass filter, a proportional-integral-differential circuit and a waveform generator.

[0054] The mixer is used for mixing and demodulating signals.

[0055] The low-pass filter is used for filtering to obtain a dispersion differential error signal.

[0056] The waveform generator is used to provide a modulation signal for the laser, input a demodulation signal into the mixer, and provide a sweep frequency signal for the laser.

[0057] The proportional-integral-differential circuit is used to control the correction signal to achieve frequency stabilization.

[0058] The present invention provides a frequency stabilization method for a Rydberg atomic receiver. According to the frequency stabilization device described above, a single alkali atomic absorption cell is used to achieve frequency stabilization of two lasers.

[0059] Specifically, the working principle of the above device is:

[0060] The frequency stabilization integrated circuit 13 outputs a modulation signal that is fed through the DC bias device 14 to the narrow-linewidth semiconductor laser controller 2. The narrow-linewidth semiconductor laser controller 2 provides adjustable drive current and temperature control for the narrow-linewidth semiconductor laser 1. The output light from the narrow-linewidth semiconductor laser 1 is reflected through the half-glass 3, polarization beam splitter prism 4, polarization beam splitter prism 5, half-glass 6, polarization beam splitter prism 7, reflector 10, reflector 11, and one end of the polarization beam splitter 9 into the alkali atomic absorption chamber 8. Laser light from the polarization beam splitter prism 7 is transmitted through the alkali atomic absorption chamber 8 and polarization beam splitter prism 9 before striking the photodetector 12, which is connected to the frequency stabilization integrated circuit 13. The frequency stabilization integrated circuit includes a built-in oscilloscope, mixer, low-pass filter, proportional-integral-differential circuit, and waveform generator. The feedback signal output by the frequency stabilization integrated circuit is connected to the drive voltage modulation port of the narrow-linewidth semiconductor laser controller 2 via the DC bias device 14. The single-frequency fiber laser controller 15 provides adjustable drive current and temperature control for the single-frequency fiber laser 16. The output light of the single-frequency fiber laser 16 is sequentially driven through the reflectors 17 and 18 into the alkali atomic absorption gas cell 8. The light from the narrow-linewidth semiconductor laser 2 passing through the polarization beam splitter 5 is sequentially passed through the reflector 23, the attenuator 24, and the alkali atomic absorption gas cell 8, and then reflected by the dichroic mirror 19. The reflected light is then driven into the photodetector 21 via the reflector 20. The modulation signal output by the photodetector 21 and the frequency stabilization integrated circuit 13 is connected to the frequency stabilization integrated circuit 22 through the DC bias device 14. The feedback signal after mixing and demodulation by the frequency stabilization integrated circuit is connected to the drive voltage modulation port of the single-frequency fiber laser 15.

[0061] The frequency locking mechanism for the narrow-linewidth semiconductor laser 1 operates as follows: In the experimental system, the narrow-linewidth semiconductor laser 1 serves as the probe light. In this invention, internal modulation is used for frequency locking. Internal modulation spectral frequency stabilization utilizes the principle that a laser beam passes through a cell containing atomic vapor (e.g., a cesium cell). The atoms' saturated absorption of the laser light produces an absorption peak. When the laser frequency matches the atomic transition frequency, absorption reaches its maximum, forming a characteristic peak. By detecting the position of this peak, the laser frequency can be precisely controlled to stabilize at a specific atomic transition frequency. Therefore, a modulation signal is input to the narrow-linewidth semiconductor laser controller 2, passed through a conventional photodetector, and then fed into an oscilloscope for observation of the saturated absorption spectrum. The modulation signal, along with the signal carrying the saturated absorption spectrum, is then demodulated in a mixer to generate a dispersion-like error signal. This signal is fed back to the laser's piezoelectric ceramic via a proportional-integral-differential circuit (PID) to control the cavity length, ultimately achieving frequency stabilization.

[0062] The frequency locking portion of the single-frequency fiber laser 16 primarily utilizes the Rydberg electromagnetically induced transparency effect to frequency-lock the laser to the Rydberg state transition frequency. In the experiment, the probe light output by the narrow-linewidth semiconductor laser 1 carries a modulation signal. This modulation signal is then mixed with the modulation signal generated by the frequency stabilization integrated circuit 13 to generate an error signal, achieving laser locking. The specific method for frequency locking the single-frequency fiber laser 16 is as follows: The light output by the single-frequency fiber laser 16 is coupled light, which passes through mirrors 17 and 18 and then through a dichroic mirror 19 into the alkali metal atomic absorption cell 8. The probe light, which carries the modulation signal and is transmitted from the narrow-linewidth semiconductor laser through the polarization beam splitter prism 5, passes through an attenuator and then to one end of the alkali metal atomic absorption cell 8. The coupled light and the probe light overlap in the alkali metal atomic cell, generating an electromagnetically induced transparency effect. This means that the probe light is no longer absorbed, resulting in a transmission peak. After passing through the alkali metal atomic absorption cell 8, the probe light is reflected by the dichroic mirror 19, split by the polarization beam splitter prism 20, and then incident on the photodetector 21. The photodetector 21 converts the received optical signal into an electrical signal and transmits it to the frequency stabilization integrated circuit 22. The mixer built into the frequency stabilization integrated circuit 22 and the frequency stabilization circuit 13 output a modulated signal, which is mixed and demodulated by the DC bias 14. The high-frequency signal is then filtered through a low-pass filter to obtain an error signal. The error signal is then transmitted to the proportional-integral-differential circuit to obtain a feedback signal. This feedback signal is then fed back to the piezoelectric ceramic of the single-frequency fiber laser 15 to control the cavity length and achieve frequency stability. In the experiment, by adjusting the parameters of the proportional-integral-differential circuit built into the frequency stabilization integrated circuit, the laser frequency can be better locked to the transmission peak generated by electromagnetically induced transparency. The electromagnetically induced transparency transmission peak and the error signal can be observed by connecting the frequency stabilization integrated circuit to a host computer.

[0063] refer to Figure 2 and Figure 3 The present invention provides a sensing device for a Rydberg atom receiver, comprising a parallel waveguide 201, an alkali metal atom gas chamber 203, an optical fiber 202, an optical fiber 204, a detection optical path, a coupling optical path, a coaxial cable, and a speaker;

[0064] The alkali metal atom gas chamber 203 is embedded in the parallel waveguide 201, the coaxial cable is used to feed the local oscillator field of the microwave source, and the horn is used to input the signal field of the microwave source;

[0065] The detection light path is used to access the fourth light path as detection light input into the optical fiber 202;

[0066] The coupling optical path is used to access the sixth optical path and input it into the optical fiber 204 as coupling light.

[0067] Furthermore, the path of the detection light path is as follows: the detection light is incident on the coupling head 30 through the optical fiber, hits the coupling head 34 through the reflector 33, is connected to the optical fiber 202, passes through the alkali metal atom gas chamber 203, and then is connected to the coupling head 29 through the optical fiber 204, and hits the detector 32 through the dichroic mirror 28 and the reflector 31.

[0068] Furthermore, the path of the coupling light path is as follows: the coupling light is connected to the optical fiber coupling head 25 through the optical fiber, and then enters the coupling head 29 through the reflector 26 , the reflector 27 , and the dichroic mirror 28 , and then is connected to the optical fiber 204 .

[0069] The working principle of the above-mentioned sensing device is as follows:

[0070] The alkali metal atom gas chamber 203 is embedded in the parallel plate waveguide 201 and used as the measurement signal field to be output through the horn antenna. The local oscillator field signal is fed into the coaxial cable end through the parallel plate waveguide 201. The local oscillator field signal is input into the mixer for mixing to generate sum frequency and difference frequency signal outputs. The difference frequency signal is also called the intermediate frequency signal. The intermediate frequency signal is filtered by the filter to remove the high frequency signal and then amplified by the intermediate frequency signal amplifier. Finally, it is detected by the measurement circuit to complete the measurement of the microwave signal.

[0071] The frequency of the single-frequency fiber laser is then stabilized at the electromagnetically induced transparency peak using a frequency stabilization technique based on the electromagnetically induced transparency effect. The eigenfield is fed through a coaxial cable and the signal microwave field is input through a speaker. The probe light is collected and injected into a photodetector, which is then connected to an oscilloscope to observe the heterodyne signal. The power of the signal field remains constant, while the power of the eigenfield is varied. The amplitude of the heterodyne signal at different eigenmicrowave field powers is recorded. Once the linear relationship between the square root of the power of the microwave source emitting the eigenfield and the signal field and its electric field strength, as well as the optimal operating point of the eigenfield, electric field sensing can be achieved.

[0072] The present invention also provides a Rydberg atomic receiver, comprising the frequency stabilization device, the detection device, an oscilloscope and a host computer; the oscilloscope is connected to the detection device, and the host computer is connected to the frequency stabilization device.

[0073] Furthermore, the host computer is wirelessly connected to the frequency stabilizing device.

[0074] The beneficial technical effects of the present invention are:

[0075] 1. The present invention achieves frequency locking of a narrow-linewidth semiconductor laser and a single-frequency fiber laser through an internal modulation method. It does not require multiple alkali metal atom gas cells or additional optical devices such as electro-optic modulators. It can achieve locking and frequency stabilization of the two lasers by relying solely on a single alkali metal atom gas cell and circuit.

[0076] 2. The present invention does not require external modulation of the detection light field, and uses a single atomic bubble for locking and sensing operations.

[0077] 3. The present invention eliminates the need to add bulky equipment traditionally used for laser locking, while providing improved portability and robustness of the sensor.

[0078] 4 The present invention does not require additional light splitting for the electromagnetically induced transparent module. Other spectroscopy techniques must use a large portion of the laser power for locking (hundreds of milliwatts in the case of Rydberg atom excitation frequencies), but the technology of the present invention uses all the control laser power available in the sensor head and only uses a small part of the detection band for locking, and the rest is used for sensing.

[0079] The above disclosure is only a preferred embodiment of the present application, and certainly cannot be used to limit the scope of rights of the present application. Therefore, equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A frequency stabilization device for a Rydberg atomic receiver, characterized in that: The invention comprises a narrow linewidth semiconductor laser, a narrow linewidth semiconductor laser controller, a single-frequency fiber laser, a single-frequency fiber laser controller, a first photodetector, a first frequency stabilization integrated circuit, a DC bias device, a second frequency stabilization integrated circuit, a first alkali metal atom gas chamber, a second photodetector and an optical path component; wherein, The laser signal emitted by the narrow-linewidth semiconductor laser is divided into four beams by the optical path component, two of which overlap facing each other at a first position in the first alkali metal atom gas chamber, are collected by the first photodetector, and are input into the first frequency stabilization integrated circuit. The first frequency stabilization integrated circuit is connected to the DC bias device, and the output modulation signal is input into the narrow-linewidth semiconductor laser controller. The narrow-linewidth semiconductor laser controller is connected to the narrow-linewidth semiconductor laser and is used to control the frequency of the narrow-linewidth semiconductor laser. The single-frequency fiber laser emits two laser signals, one of which coincides with one of the remaining two laser signals emitted by the narrow-linewidth semiconductor laser after passing through the optical path component at a second position in the first alkali metal atom gas chamber. The signals are collected by the second photodetector and input into the second frequency stabilization integrated circuit. The second frequency stabilization integrated circuit is connected to the single-frequency fiber laser controller and the DC bias device. The second frequency stabilization integrated circuit is connected to the single-frequency fiber laser controller. The single-frequency fiber laser controller is connected to the single-frequency fiber laser for controlling the frequency of the single-frequency fiber laser. The optical path component includes a first half-wave plate, a first polarization beam splitter prism, a second polarization beam splitter prism, a second half-wave plate, a third polarization beam splitter prism, a fourth polarization beam splitter prism, a first reflector, a second reflector, a first dichroic mirror, a third reflector, a fourth reflector and an attenuation plate; The first optical path of the laser signal emitted by the narrow linewidth semiconductor laser passes through the first half-wave plate, one end of the first polarization beam splitter prism, one end of the second polarization beam splitter prism, the second half-wave plate, one end of the third polarization beam splitter prism, the first reflector, the second reflector, and one end of the fourth polarization beam splitter prism and is reflected into the first position of the first alkali metal atom gas cell; The second optical path of the laser signal emitted by the narrow linewidth semiconductor laser passes through the other end of the third polarization splitter prism and is directly incident on the first alkali metal atom gas chamber, overlapping with the first optical path at the first position, and then passes through the other end of the fourth polarization splitter prism and is incident on the first photodetector; The third optical path of the laser signal emitted by the narrow linewidth semiconductor laser passes through the other end of the second polarization beam splitter prism, the fourth reflector, and the attenuation plate, and is incident on the second position of the first alkali metal atom gas cell. The third optical path is reflected by the first dichroic mirror, and the reflected light is incident on the second photodetector via the third reflector. The fourth optical path of the laser signal emitted by the narrow linewidth semiconductor laser passes through the other end of the first polarization beam splitter prism and is directly emitted for electric field sensing measurement; The fifth beam of the laser signal emitted by the single-frequency fiber laser passes through the first dichroic mirror and enters the second position of the first alkali metal atom gas chamber; The sixth optical path of the laser signal emitted by the single-frequency fiber laser is directly emitted and used for electric field sensing measurement.

2. The frequency stabilizing device according to claim 1, wherein: The optical path assembly also includes a fifth reflector and a sixth reflector, which are sequentially arranged between the single-frequency fiber laser and the first dichroic mirror, and are used to adjust the direction of the optical path and direct the fifth beam of light into the second position of the first alkali metal atom gas chamber.

3. The frequency stabilizing device according to claim 1, wherein: The first frequency stabilizing integrated circuit and the second frequency stabilizing integrated circuit each have a built-in first oscilloscope, a mixer, a low-pass filter, a proportional-integral-differential circuit, and a waveform generator; The mixer is used for mixing and demodulating signals; The low-pass filter is used for filtering to obtain a dispersion differential error signal; The waveform generator is used to provide a modulation signal for the laser, input it into the mixer for demodulation, and provide a sweep frequency signal for the laser; The proportional-integral-differential circuit is used to control the correction signal to achieve frequency stabilization.

4. A frequency stabilization method for a Rydberg atom receiver, characterized in that: According to the frequency stabilization device according to any one of claims 1 to 3, the frequency stabilization of two lasers is achieved by using a single alkali metal atomic absorption gas cell.

5. A Rydberg atom receiver, characterized in that: The device comprises a frequency stabilizing device according to any one of claims 1 to 3, a sensor device, a second oscilloscope, and a host computer; the second oscilloscope is connected to the sensor device, and the host computer is connected to the frequency stabilizing device; The sensing device includes a parallel waveguide, a second alkali metal atom gas chamber, a first optical fiber, a second optical fiber, a detection optical path, a coupling optical path, a coaxial cable and a speaker; The second alkali metal atom gas cell is embedded in the parallel waveguide, the coaxial cable is used to feed the local oscillator field of the microwave source, and the horn is used to input the signal field of the microwave source; The detection light path is used to access the fourth light path described in claim 1 and input it into the first optical fiber as the detection light; The coupling optical path is used to access the sixth optical path described in claim 1 and input it into the second optical fiber as coupling light.

6. According to the Rydberg atom receiver of claim 5, the path of the detection light path is as follows: the detection light is incident on the first coupling head through the optical fiber, is hit by the second coupling head through the seventh reflector, is connected to the first optical fiber, passes through the second alkali metal atom gas chamber, and then is connected to the third coupling head through the second optical fiber, and is hit by the second dichroic mirror and the eighth reflector into the third detector.

7. The Rydberg atom receiver according to claim 5, wherein the coupling optical path is as follows: the coupling light is connected to the first optical fiber coupling head through the optical fiber, then passes through the ninth reflector, the tenth reflector, and the second dichroic mirror to enter the third coupling head, and then is connected to the second optical fiber.

8. The Rydberg atom receiver according to claim 5, characterized in that The host computer is wirelessly connected to the frequency stabilizing device.

Images