A weak electric field signal detection method and system

Abstract

The present application relates to the technical field of signal detection, in particular to a weak electric field signal detection method and system. The present application obtains the complete information of the frequency, amplitude and phase of the to-be-detected electric field signal in one measurement of the injection-locked phonon laser, wherein the to-be-detected laser amplitude spectrum and the to-be-detected laser phase spectrum are generated by the same injection-locked phonon laser, and the received amplitude signal and phase signal must arrive at the same time, which are simultaneous in time and naturally orthogonal in physics; therefore, the to-be-detected electric field information is obtained by analyzing the laser amplitude spectrum and the to-be-detected laser phase spectrum, which is more accurate than the traditional dual-phase lock amplifier analyzing two different to-be-detected signals received by two mixers, and solves the technical problem of measurement error caused by the deviation of the to-be-detected signals received by the two mixers in the traditional dual-phase lock amplifier.

Description

Technical Field

[0001] This invention relates to the field of signal detection technology, and in particular to a method and system for detecting weak electric field signals. Background Technology

[0002] In modern science and engineering, highly sensitive measurement of weak electric field signals against a noisy background is a crucial issue, playing a vital role in many applications such as earthquake monitoring, medical diagnosis, materials science, and communication engineering, and is closely related to the national economy and people's daily lives. Currently, monitoring weak electric field signals requires not only highly sensitive instruments but also effective signal processing techniques to extract useful signals from the noise. Traditional signal detection methods include correlation detection using Fourier transform or wavelet transform. These methods are highly effective when processing signals with high signal-to-noise ratios (SNR), but often exhibit significant errors when dealing with signals with extremely low SNRs.

[0003] To overcome the limitations of the aforementioned methods, phase-locked loop (PLL) measurement technology, which maintains high sensitivity for signal extraction even in noisy environments, has attracted widespread attention. PLL amplifiers, developed based on PLL technology, detect signals by mixing the frequency of the input signal with a reference signal to convert the target frequency component into a DC signal, while other components are filtered out. This technique employs a zero-difference detection scheme involving frequency mixing with the reference signal, followed by adjustable low-pass filtering, to extract the target signal output from noisy environments. However, for the test signal with an unknown phase, traditional single-reference signal PLL technology cannot function, requiring the use of two orthogonal reference signals for dual-phase-locked measurement to achieve vector tracking.

[0004] Traditional dual-phase lock-in amplifiers (LPAs) simultaneously input the signal to be measured into two mixers on both sides of the LPA. Two orthogonal eigensignals are used to mix the signal with the signal to be measured. The resulting mixture is then filtered to obtain information such as the amplitude and phase of the signal to be measured. However, ideally, the signals to be measured received by the two mixers of the LPA should be exactly the same. This condition is impossible to achieve under real-world measurement conditions because phase noise in the circuitry and electronic components of the LPA can prevent the two mixers from receiving the signal to be measured simultaneously, leading to errors in the signal detected by the LPA. Therefore, improving the detection accuracy of weak electric field signals remains a pressing problem in this field. Summary of the Invention

[0005] The present invention aims to provide a method and system for detecting weak electric field signals, which can simultaneously obtain complete information on the frequency, amplitude and phase of the electric field signal under test in a single measurement, so as to solve the technical problem that the measured signals received by the two mixers in the traditional dual-phase lock-in amplifier are deviated, resulting in measurement errors.

[0006] To achieve the above objectives, the first aspect of the present invention provides a method for detecting weak electric field signals, comprising the following steps:

[0007] An ion trap is generated in a preset vacuum cavity; a primitive phonon laser is generated in the ion trap; the primitive phonon laser is injected and locked to obtain an injected and locked phonon laser; a test electric field signal is input into the ion trap to cause the test electric field signal and the injected and locked phonon laser to mix; the test laser amplitude spectrum and test laser phase spectrum of the injected and locked phonon laser are obtained; the test laser amplitude spectrum and test laser phase spectrum are analyzed based on a preset phonon laser-electric field signal model to obtain the test information of the test electric field signal.

[0008] The aforementioned method for detecting weak electric field signals utilizes the injection-locking principle of phonon lasers. After the signal to be measured is input into the ion trap, the electric field signal will mix with the injected-locked phonon laser, perturbing its motion. This causes the amplitude and phase of the injected-locked phonon laser to change periodically over time, and the properties of the electric field signal to be measured are reflected in these amplitude and phase changes. By measuring the real-time changes in the amplitude and phase of the phonon laser, the amplitude spectrum and phase spectrum of the laser to be measured are obtained, allowing analysis of the frequency, amplitude, and phase information of the corresponding electric field signal. Since the properties of the amplitude and phase spectra of the injected-locked phonon laser are only affected by the electric field signal that mixes with it, obtaining the measured information of the electric field signal based on these spectra can effectively filter out the influence of noise signals. This makes the method beneficial for improving the accuracy of detecting weak electric field signals in noisy environments.

[0009] The above method simultaneously obtains complete information on the frequency, amplitude, and phase of the electric field signal under test in a single measurement of an injected locked phonon laser. The amplitude spectrum and phase spectrum of the laser under test are generated by the same injected locked phonon laser, and the received amplitude and phase signals arrive simultaneously, exhibiting temporal simultaneity and natural orthogonality. Therefore, analyzing the laser amplitude and phase spectra to obtain the electric field information is more accurate than analyzing two asynchronous signals received by two mixers in a traditional dual-phase lock-in amplifier. This method solves the technical problem of measurement error caused by deviations in the signals received by the two mixers in a traditional dual-phase lock-in amplifier.

[0010] Preferably, generating a primitive phonon laser in the ion trap includes:

[0011] Trapped ions are introduced into the ion trap; red detuned laser and cooling laser are introduced into the ion trap to cool the trapped ions; red detuned laser and blue detuned laser are introduced into the ion trap to cause the trapped ions to generate primordial phonon lasers.

[0012] In this implementation, a red-detuned laser and a blue-detuned laser beam are used together to act on a single trapped ion in an ion trap, exciting the trapped ion and amplifying its vibration amplitude to form a primitive phonon laser in single-ion form. Specifically, the red-detuned laser and the cooling laser are coupled together and input to the ion trap located in the vacuum cavity to cool the trapped ion and achieve stable ion trapping; the red-detuned laser and the blue-detuned laser are coupled together and input to the ion trap located in the vacuum cavity to act on the cooled trapped ion to generate a primitive phonon laser.

[0013] Preferably, the injection locking of the original phonon laser to obtain an injection-locked phonon laser includes:

[0014] An injection-lock signal is input into the ion trap; the vibration frequency of the original phonon laser is obtained; the frequency of the injection-lock signal is adjusted so that the frequency of the injection-lock signal is the same as the vibration frequency of the original phonon laser, thereby causing the injection-lock signal to inject and lock the original phonon laser, thus obtaining an injection-locked phonon laser.

[0015] In this implementation, a sinusoidal signal is generated and input into the ion trap. The frequency of the sinusoidal signal is adjusted to be the same as the vibration frequency of the original phonon laser, so that the sinusoidal signal acts as an injection-locking signal to lock the original phonon laser. At this time, the amplitude of the original phonon laser is further amplified, thereby generating an injection-locked phonon laser.

[0016] Preferably, obtaining the amplitude spectrum and phase spectrum of the injected locked phonon laser includes:

[0017] The spontaneous emission fluorescence signal of the injected locked phonon laser is acquired, and then the time distribution of the spontaneous emission fluorescence signal is obtained; the time distribution of the spontaneous emission fluorescence signal is fitted to obtain the amplitude spectrum and phase spectrum of the laser to be tested.

[0018] In this implementation, the amplitude and phase of the injected and locked single-ion phonon laser affect the spontaneous emission rate of the phonon laser ions. By statistically analyzing the time distribution of the spontaneous emission fluorescence signal of the injected and locked phonon laser, the spontaneous emission rate of the phonon laser ions can be obtained. Then, by fitting the measured time distribution of the spontaneous emission response signal of the phonon laser ions, the real-time amplitude and phase change information of the injected and locked phonon laser can be obtained, thereby obtaining the amplitude spectrum and phase spectrum of the laser to be measured.

[0019] Preferably, the step of analyzing the amplitude spectrum and phase spectrum of the laser to be measured based on a preset phonon laser-electric field signal model to obtain the measurement information of the electric field signal to be measured includes:

[0020] Several standard electric field signals are input into the ion trap to obtain the standard laser amplitude spectrum and standard laser phase spectrum corresponding to each of the standard electric field signals for the injected locked phonon laser; based on each of the standard electric field signals and the standard laser amplitude spectrum and standard laser phase spectrum corresponding to each of the standard electric field signals, a phonon laser-electric field signal model is constructed.

[0021] In this implementation, several sinusoidal signals are generated as standard electric field signals and input into the ion trap. For any one of these standard electric field signals input into the ion trap, when the injected-locked phonon laser is affected by a standard electric field signal, the real-time amplitude and phase changes of the injected-locked phonon laser will change accordingly. By recording and analyzing the real-time amplitude and phase changes of the injected-locked phonon laser under different frequency, amplitude, and phase standard electric field signal input conditions, a functional relationship between the frequency, amplitude, and phase of the input electric field signal and the amplitude and phase spectra of the injected-locked phonon laser can be constructed, thus obtaining a phonon laser-electric field signal model. Using this phonon laser-electric field signal model, the frequency, amplitude, and phase values ​​of the electric field signal corresponding to the amplitude and phase spectra of the laser under test can be analyzed in reverse, serving as the detection result of the electric field signal under test.

[0022] In another possible implementation of this preferred embodiment, only a standard electric field signal is input to the ion trap. By changing the frequency, amplitude, and phase of the standard electric field signal, the real-time variation law of the amplitude and phase of the injected locked phonon laser corresponding to different frequencies, amplitudes, and phases of the standard electric field signal is recorded and analyzed. This allows the construction of a functional relationship between the frequency, amplitude, and phase of the input electric field signal and the amplitude and phase spectra of the injected locked phonon laser, ultimately yielding a phonon laser-electric field signal model.

[0023] A second aspect of the present invention provides a weak electric field signal detection system, comprising a vacuum module, a trapped field module, a laser module, a detection module, and a fluorescence imaging detection module, wherein:

[0024] The vacuum module includes a vacuum chamber and an ion pump, the ion pump being used to maintain the vacuum level of the vacuum chamber;

[0025] The trapping field module is used to generate an ion trap in the vacuum cavity;

[0026] The laser module is used to generate a primitive phonon laser in the ion trap;

[0027] The detection module is used to inject and lock the original phonon laser to obtain an injected and locked phonon laser, and then input the electric field signal to be measured into the ion trap so that the electric field signal to be measured and the injected and locked phonon laser will produce a mixing effect.

[0028] The fluorescence imaging detection module is used to acquire the amplitude spectrum and phase spectrum of the injected locked phonon laser, and then analyze the amplitude spectrum and phase spectrum of the laser under test based on a preset phonon laser-electric field signal model to obtain the test information of the electric field signal under test.

[0029] In this implementation, maintaining the vacuum level of the vacuum cavity using an ion pump improves its stability and enhances the accuracy of subsequent electric field signal measurements. The ion trap generated within the vacuum cavity forms a trapping electric field that effectively captures and traps laser ions, providing a highly stable reaction space for mixing the electric field signal to be measured with the injected locked phonon laser. Since the amplitude and phase spectra of the injected locked phonon laser are only affected by the electric field signal that mixes with it, obtaining the measured information of the electric field signal based on these spectra effectively filters out the influence of noise signals. This makes the method beneficial for improving the accuracy of detecting weak electric field signals in noisy environments.

[0030] The above method simultaneously obtains complete information on the frequency, amplitude, and phase of the electric field signal under test in a single measurement of an injected locked phonon laser. The amplitude spectrum and phase spectrum of the laser under test are generated by the same injected locked phonon laser, and the received amplitude and phase signals arrive simultaneously, exhibiting temporal simultaneity and natural orthogonality. Therefore, analyzing the laser amplitude and phase spectra to obtain the electric field information is more accurate than analyzing two asynchronous signals received by two mixers in a traditional dual-phase lock-in amplifier. This method solves the technical problem of measurement error caused by deviations in the signals received by the two mixers in a traditional dual-phase lock-in amplifier.

[0031] Preferably, the trapping field module includes a DC power supply, a radio frequency power supply, and an ion trap chip, wherein the ion trap chip is disposed in the vacuum cavity; wherein:

[0032] The DC power supply and the RF power supply are used to power the ion trap chip so that the ion trap chip generates an ion trap in the vacuum cavity.

[0033] Preferably, the laser module includes a photoionization laser, a first laser, a second laser, a red-detuned acousto-optic modulator, and a blue-detuned acousto-optic modulator; wherein:

[0034] The photoionization laser is used to input trapped ions into the ion trap;

[0035] The first laser is used to inject the first laser into the red detuned acousto-optic modulator and the blue detuned acousto-optic modulator respectively, so that the red detuned acousto-optic modulator generates red detuned laser and the blue detuned acousto-optic modulator generates blue detuned laser.

[0036] The second laser is used to generate a cooling laser;

[0037] The red-detuned acousto-optic modulator and the second laser are also used to input red-detuned laser and cooling laser into the ion trap to cool the trapped ions;

[0038] The red-detuned acousto-optic modulator and the blue-detuned acousto-optic modulator are also used to input red-detuned laser and blue-detuned laser into the ion trap so that the trapped ions generate primitive phonon lasers.

[0039] In this implementation, atoms are ionized via photoionization to generate trapped ions, which are then input into an ion trap within a vacuum cavity. The ion trap confines the trapped ions within its region using a trapping electric field. The emitted laser from the first laser is modulated by a red-detuned acousto-optic modulator, becoming a red-detuned laser output; similarly, it is modulated by a blue-detuned acousto-optic modulator, becoming a blue-detuned laser output. The red-detuned laser and the cooling laser are coupled together into the vacuum cavity and input into the ion trap located within it, cooling the trapped ions and achieving stable ion trapping. The red-detuned laser and the blue-detuned laser are coupled together into the vacuum cavity and input into the ion trap located within it, acting on the cooled trapped ions to produce a single-ion pristine phonon laser.

[0040] Preferably, the detection module includes an arbitrary wave generator and a port for the electric field signal to be measured; the step of injecting and locking the original phonon laser to obtain an injected and locked phonon laser, and then inputting the electric field signal to be measured into the ion trap to cause the electric field signal to be measured and the injected and locked phonon laser to produce a mixing effect, includes:

[0041] An injection lock signal is input to the ion trap via the arbitrary wave generator;

[0042] Obtain the vibration frequency of the original phonon laser;

[0043] The frequency of the injection locking signal is adjusted so that the frequency of the injection locking signal is the same as the vibration frequency of the original phonon laser, thereby causing the injection locking signal to inject and lock the original phonon laser, resulting in an injection-locked phonon laser.

[0044] The electric field signal to be measured is input to the ion trap through the electric field signal port to cause the electric field signal to be measured and the injected locked phonon laser to generate a mixing effect.

[0045] Preferably, the fluorescence imaging detection module includes an imaging mirror, a charge-coupled device (CCD), and a photomultiplier tube (PMT), wherein:

[0046] The imaging mirror is used to image and magnify the injected locked phonon laser;

[0047] The charge-coupled device is used to acquire the spontaneous emission fluorescence signal of the injected locked phonon laser through the imaging mirror, thereby monitoring the spatial position and motion state of the trapped ions;

[0048] The photomultiplier tube is used to acquire the spontaneous emission fluorescence signal of the injected locked phonon laser through the imaging mirror, so as to obtain the time distribution of the spontaneous emission fluorescence signal, and then fit the time distribution of the spontaneous emission fluorescence signal to obtain the amplitude spectrum and phase spectrum of the laser to be measured.

[0049] In this implementation, the temporal distribution of the spontaneous emission fluorescence signal of the ions that generate the injected-locked phonon laser is collected and statistically analyzed using synchronous measurement technology of ion spontaneous emission fluorescence signal. Specifically, this represents the change in the number of photons of the injected-locked phonon laser over a certain period of time. By curve fitting the temporal distribution of the spontaneous emission fluorescence signal, a fitting curve with time as the abscissa can be obtained, thereby yielding the amplitude spectrum and phase spectrum of the laser to be measured. Attached Figure Description

[0050] Figure 1 This is a flowchart illustrating a method for detecting weak electric field signals provided in an embodiment of the present invention;

[0051] Figure 2 This is a schematic diagram of a weak electric field signal detection system provided in an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of another weak electric field signal detection system provided in an embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of another weak electric field signal detection system provided in an embodiment of the present invention;

[0054] Figure 5 This is a partial structural schematic diagram of a weak electric field signal detection system provided in an embodiment of the present invention;

[0055] Figure 6a This is a schematic diagram of a process for acquiring spontaneous emission fluorescence signals using a photomultiplier tube, provided in an embodiment of the present invention.

[0056] Figure 6b This is a timing diagram for measuring the amplitude and phase of an injection-locked phonon laser, provided in an embodiment of the present invention.

[0057] Figure 7 This is a time distribution diagram of spontaneous emission fluorescence from an injection-locked phonon laser provided in an embodiment of the present invention;

[0058] Figure 8 This is a graph showing the variation of the amplitude and phase of the injected locked phonon laser under the action of a standard electric field signal, as provided in an embodiment of the present invention.

[0059] Figure 9 This is a graph showing the variation of the frequency of the injection-locked phonon laser amplitude and phase fluctuations over time with the detuning amount between the standard electric field signal and the injection-locked signal, provided in an embodiment of the present invention.

[0060] Figure 10 This is a diagram showing the variation of the initial phase of the injected locked phonon laser amplitude and phase with the phase of the standard electric field signal, provided in an embodiment of the present invention.

[0061] Figure 11 This is a graph showing the variation of the amplitude and phase of the injected locked phonon laser over time with the amplitude of the standard electric field signal, as provided in an embodiment of the present invention.

[0062] The components are as follows: 100, Vacuum Module; 110, Vacuum Chamber; 120, Ion Pump; 200, Trapping Field Module; 210, DC Power Supply; 220, RF Power Supply; 230, Ion Trap Chip; 300, Laser Module; 310, Photoionizing Laser; 320, First Laser; 330, Second Laser; 340, Red Detuned Acousto-Optical Modulator; 350, Blue Detuned Acousto-Optical Modulator; 370a, First Isolator; 370b, Second Isolator; 400, Detection Module; 410, Arbitrary Wave Generator; 500, Fluorescence Imaging Detection Module; 510, Imaging Mirror; 520, Photomultiplier Tube; 530, Charge-Coupled Element; 600a, First Polarization Spectrum Splitter; 600b, Second Polarization Spectrum Splitter; 600c, Third Polarization Spectrum Splitter; 600d, Fourth Polarization Spectrum Splitter; 600e, Fifth Polarization Spectrum Splitter. Detailed Implementation

[0063] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that the following detailed descriptions are exemplary and intended to provide further detailed explanation of the invention. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings are used to distinguish different objects, not to describe a particular order.

[0064] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0065] In modern science and engineering, highly sensitive measurement of weak electric field signals against a noisy background is a crucial issue, playing a vital role in many applications such as earthquake monitoring, medical diagnosis, materials science, and communication engineering, and is closely related to the national economy and people's daily lives. Currently, monitoring weak electric field signals requires not only highly sensitive instruments but also effective signal processing techniques to extract useful signals from the noise. Traditional signal detection methods include correlation detection using Fourier transform or wavelet transform. These methods are highly effective when processing signals with high signal-to-noise ratios (SNR), but often exhibit significant errors when dealing with signals with extremely low SNRs.

[0066] To overcome the limitations of the aforementioned methods, phase-locked loop (PLL) measurement technology, which maintains high sensitivity for signal extraction even in noisy environments, has attracted widespread attention. PLL amplifiers, developed based on PLL technology, detect signals by mixing the frequency of the input signal with a reference signal to convert the target frequency component into a DC signal, while other components are filtered out. This technique employs a zero-difference detection scheme involving frequency mixing with the reference signal, followed by adjustable low-pass filtering, to extract the target signal output from noisy environments. However, for the test signal with an unknown phase, traditional single-reference signal PLL technology cannot function, requiring the use of two orthogonal reference signals for dual-phase-locked measurement to achieve vector tracking.

[0067] Traditional dual-phase lock-in amplifiers (LPAs) simultaneously input the signal to be measured into two mixers on both sides of the LPA. Two orthogonal eigensignals are used to mix the signal with the signal to be measured. The resulting mixture is then filtered to obtain information such as the amplitude and phase of the signal to be measured. However, ideally, the signals to be measured received by the two mixers of the LPA should be exactly the same. This condition is impossible to achieve under real-world measurement conditions because phase noise in the circuitry and electronic components of the LPA can prevent the two mixers from receiving the signal to be measured simultaneously, leading to errors in the signal detected by the LPA. Therefore, improving the detection accuracy of weak electric field signals remains a pressing problem in this field.

[0068] To solve the above technical problems, refer to Figure 1 The first embodiment of the present invention provides a method for detecting weak electric field signals, comprising the following steps:

[0069] S101. An ion trap is generated in a preset vacuum chamber 110;

[0070] S102, Generating a primitive phonon laser in the ion trap;

[0071] S103. The original phonon laser is injected and locked to obtain an injected and locked phonon laser.

[0072] S104. Input the electric field signal to be measured into the ion trap so that the electric field signal to be measured and the injected locked phonon laser will have a mixing effect.

[0073] S105. Obtain the amplitude spectrum and phase spectrum of the injected locked phonon laser.

[0074] S106. Analyze the amplitude spectrum and phase spectrum of the laser to be tested based on the preset phonon laser-electric field signal model to obtain the test information of the electric field signal to be tested.

[0075] The aforementioned method for detecting weak electric field signals utilizes the injection-locking principle of phonon lasers. After the signal to be measured is input into the ion trap, the electric field signal will mix with the injected-locked phonon laser, perturbing its motion. This causes the amplitude and phase of the injected-locked phonon laser to change periodically over time, and the properties of the electric field signal to be measured are reflected in these amplitude and phase changes. By measuring the real-time changes in the amplitude and phase of the phonon laser, the amplitude spectrum and phase spectrum of the laser to be measured are obtained, allowing analysis of the frequency, amplitude, and phase information of the corresponding electric field signal. Since the properties of the amplitude and phase spectra of the injected-locked phonon laser are only affected by the electric field signal that mixes with it, obtaining the measured information of the electric field signal based on these spectra can effectively filter out the influence of noise signals. This makes the method beneficial for improving the accuracy of detecting weak electric field signals in noisy environments.

[0076] The above method simultaneously obtains complete information on the frequency, amplitude, and phase of the electric field signal under test in a single measurement of an injected locked phonon laser. The amplitude spectrum and phase spectrum of the laser under test are generated by the same injected locked phonon laser, and the received amplitude and phase signals arrive simultaneously, exhibiting temporal simultaneity and natural orthogonality. Therefore, analyzing the laser amplitude and phase spectra to obtain the electric field information is more accurate than analyzing two asynchronous signals received by two mixers in a traditional dual-phase lock-in amplifier. This method solves the technical problem of measurement error caused by deviations in the signals received by the two mixers in a traditional dual-phase lock-in amplifier.

[0077] Preferably, generating a primitive phonon laser in the ion trap includes:

[0078] Trapped ions are introduced into the ion trap. 40 Ca +A 397nm red detuned laser and an 866nm cooling laser are input into the ion trap to achieve Doppler cooling of the trapped ions. 40 Ca + Cooling is performed; a 397nm red detuned laser and a 397nm blue detuned laser are input into the ion trap to cause the trapped ions to generate primitive phonon lasers.

[0079] In this implementation, a red-detuned laser and a blue-detuned laser beam are used together to act on a single trapped ion in an ion trap, exciting the trapped ion and amplifying its vibration amplitude to form a primitive phonon laser in single-ion form. Specifically, the red-detuned laser and the cooling laser are coupled together and input to the ion trap located in the vacuum cavity 110 to cool the trapped ion and achieve stable ion trapping; the red-detuned laser and the blue-detuned laser are coupled together and input to the ion trap located in the vacuum cavity 110 to act on the cooled trapped ion to generate a primitive phonon laser.

[0080] Preferably, the injection locking of the original phonon laser to obtain an injection-locked phonon laser includes:

[0081] An injection-lock signal is input into the ion trap; the vibration frequency of the original phonon laser is obtained; the frequency of the injection-lock signal is adjusted so that the frequency of the injection-lock signal is the same as the vibration frequency of the original phonon laser, thereby causing the injection-lock signal to inject and lock the original phonon laser, thus obtaining an injection-locked phonon laser.

[0082] In this implementation, a sinusoidal signal is generated and input into the ion trap. The frequency of the sinusoidal signal is adjusted to be the same as the vibration frequency of the original phonon laser, so that the sinusoidal signal acts as an injection-locking signal to lock the original phonon laser. At this time, the amplitude of the original phonon laser is further amplified, thereby generating an injection-locked phonon laser.

[0083] Preferably, obtaining the amplitude spectrum and phase spectrum of the injected locked phonon laser includes:

[0084] The spontaneous emission fluorescence signal of the injected locked phonon laser is acquired, and then the time distribution of the spontaneous emission fluorescence signal is obtained; the time distribution of the spontaneous emission fluorescence signal is fitted to obtain the amplitude spectrum and phase spectrum of the laser to be tested.

[0085] In this implementation, the amplitude and phase of the injected and locked single-ion phonon laser affect the spontaneous emission rate of the phonon laser ions. By statistically analyzing the time distribution of the spontaneous emission fluorescence signal of the injected and locked phonon laser, the spontaneous emission rate of the phonon laser ions can be obtained. Then, by fitting the measured time distribution of the spontaneous emission response signal of the phonon laser ions, the real-time amplitude and phase change information of the injected and locked phonon laser can be obtained, thereby obtaining the amplitude spectrum and phase spectrum of the laser to be measured.

[0086] Preferably, the step of analyzing the amplitude spectrum and phase spectrum of the laser to be measured based on a preset phonon laser-electric field signal model to obtain the measurement information of the electric field signal to be measured includes:

[0087] Several standard electric field signals are input into the ion trap to obtain the standard laser amplitude spectrum and standard laser phase spectrum corresponding to each of the standard electric field signals for the injected locked phonon laser; based on each of the standard electric field signals and the standard laser amplitude spectrum and standard laser phase spectrum corresponding to each of the standard electric field signals, a phonon laser-electric field signal model is constructed.

[0088] In this implementation, several sinusoidal signals are generated as standard electric field signals and input into the ion trap. For any one of these standard electric field signals input into the ion trap, when the injected-locked phonon laser is affected by a standard electric field signal, the real-time amplitude and phase changes of the injected-locked phonon laser will change accordingly. By calibrating the real-time amplitude and phase changes of the injected-locked phonon laser under different frequency, amplitude, and phase standard electric field signal input conditions, a functional relationship between the frequency, amplitude, and phase of the input electric field signal and the amplitude and phase spectra of the injected-locked phonon laser can be constructed, thus obtaining a phonon laser-electric field signal model. Using this phonon laser-electric field signal model, the frequency, amplitude, and phase values ​​of the electric field signals corresponding to the amplitude and phase spectra of the laser under test can be analyzed in reverse, serving as the detection results of the electric field signal under test.

[0089] In another possible implementation of this preferred embodiment, only a standard electric field signal is input to the ion trap. This standard electric field signal is superimposed with the injection-locking signal and then input together into the ion trap electrode. Simultaneously, a phonon laser-electric field signal model is obtained while the original phonon laser is being injected and locked. Specifically, by changing the frequency, amplitude, and phase of the standard electric field signal, the real-time amplitude and phase variation patterns of the injected-locked phonon laser under different frequencies, amplitudes, and phases of the standard electric field signal are calibrated. This allows the construction of a functional relationship between the frequency, amplitude, and phase of the input electric field signal and the amplitude and phase spectra of the injected-locked phonon laser, ultimately yielding the phonon laser-electric field signal model.

[0090] Reference Figure 2 The second embodiment of the present invention provides a weak electric field signal detection system, which includes a vacuum module 100, a confinement field module 200, a laser module 300, a detection module 400, and a fluorescence imaging detection module 500, wherein:

[0091] The vacuum module 100 includes a vacuum chamber 110 and an ion pump 120, the ion pump 120 being used to maintain the vacuum level of the vacuum chamber 110; specifically, a metal angle valve and the ion pump 120 are used to maintain the vacuum chamber 110 at a vacuum level of 10. -9 Pa level or above;

[0092] The trapping field module 200 is used to generate an ion trap in the vacuum cavity 110;

[0093] The laser module 300 is used to generate a primitive phonon laser in the ion trap, and then inject and lock the primitive phonon laser to obtain an injected and locked phonon laser.

[0094] The detection module 400 is used to inject and lock the original phonon laser to obtain an injected and locked phonon laser, and then input the electric field signal to be measured into the ion trap so that the electric field signal to be measured and the injected and locked phonon laser will have a mixing effect.

[0095] The fluorescence imaging detection module 500 is used to acquire the amplitude spectrum and phase spectrum of the injected locked phonon laser, and then analyze the amplitude spectrum and phase spectrum of the laser under test based on a preset phonon laser-electric field signal model to obtain the test information of the electric field signal under test.

[0096] In this implementation, the ion pump 120 maintains the vacuum level of the vacuum cavity 110, which helps improve the stability of the vacuum cavity 110 and the accuracy of subsequent electric field signal measurements. The ion trap generated in the vacuum cavity 110 forms a trapping electric field that captures and traps laser ions, effectively capturing and trapping the original phonon laser and the electric field signal to be measured, providing a highly stable reaction space for mixing the electric field signal to be measured and the injected locked phonon laser. Since the amplitude spectrum and phase spectrum of the injected locked phonon laser to be measured are only affected by the electric field signal to be measured that mixes with it, the measured information of the electric field signal to be measured based on the amplitude spectrum and phase spectrum of the laser to be measured can effectively filter out the influence of noise signals, making the above method beneficial for improving the accuracy of detecting weak electric field signals in a noisy background.

[0097] The above method simultaneously obtains complete information on the frequency, amplitude, and phase of the electric field signal under test in a single measurement of an injected locked phonon laser. The amplitude spectrum and phase spectrum of the laser under test are generated by the same injected locked phonon laser, and the received amplitude and phase signals arrive simultaneously, exhibiting temporal simultaneity and natural orthogonality. Therefore, analyzing the laser amplitude and phase spectra to obtain the electric field information is more accurate than analyzing two asynchronous signals received by two mixers in a traditional dual-phase lock-in amplifier. This method solves the technical problem of measurement error caused by deviations in the signals received by the two mixers in a traditional dual-phase lock-in amplifier.

[0098] Reference Figure 3 Preferably, the trapping field module 200 includes a DC power supply 210, a radio frequency power supply 220, and an ion trap chip 230, wherein the ion trap chip 230 is disposed in the vacuum chamber 110; wherein:

[0099] The DC power supply 210 and the RF power supply 220 are used to supply power to the ion trap chip 230 so that the ion trap chip 230 generates an ion trap in the vacuum cavity 110.

[0100] Reference Figure 3 Preferably, the laser module 300 includes a photoionization laser 310, a first laser 320, a second laser 330, a red detuned acousto-optic modulator 340, and a blue detuned acousto-optic modulator 350; wherein:

[0101] The photoionizing laser 310 is used to input trapped ions into the ion trap; specifically, the ionizing laser ionizes calcium atoms ejected from the atomic furnace and loads them into the trapping potential well of the chip ion trap.

[0102] The first laser 320 is used to incident the first laser onto the red detuned acousto-optic modulator 340 and the blue detuned acousto-optic modulator 350 respectively, so that the red detuned acousto-optic modulator 340 generates red detuned laser and the blue detuned acousto-optic modulator 350 generates blue detuned laser.

[0103] The second laser 330 is used to generate a cooling laser;

[0104] The red detuned acousto-optic modulator 340 and the second laser 330 are also used to input red detuned laser and cooling laser into the ion trap to cool the trapped ions;

[0105] The red-detuned acousto-optic modulator 340 and the blue-detuned acousto-optic modulator 350 are also used to input red-detuned laser and blue-detuned laser into the ion trap so that the trapped ions generate primitive phonon lasers.

[0106] In this implementation, atoms are ionized by photoionization to generate trapped ions, which are then input into an ion trap within the vacuum cavity 110. The ion trap confines the trapped ions within its region using a trapping electric field. An ion trap chip 230 is placed in the vacuum cavity 110. A DC power supply 210 and a radio frequency power supply 220 power the ion trap electrodes to generate a stable trapping electric field. The emitted laser from the first laser 320 is modulated by a red-detuned acousto-optic modulator 340, becoming a red-detuned laser output. The emitted laser from the first laser 320 is also modulated by a blue-detuned acousto-optic modulator 350, becoming a blue-detuned laser output. The red-detuned laser and the cooling laser are coupled together into the vacuum cavity 110, thus inputting into the ion trap located within the vacuum cavity 110 to cool the trapped ions and achieve stable ion trapping. The red detuned laser and the blue detuned laser are coupled together into the vacuum cavity 110 and input into the ion trap located in the vacuum cavity 110, acting on the cooled trapped ions to produce a single-ion original phonon laser.

[0107] Reference Figure 3 Preferably, the detection module 400 includes an arbitrary wave generator 410 (AWG) and a port for the electric field signal to be measured; the step of injecting and locking the original phonon laser to obtain an injected and locked phonon laser, and then inputting the electric field signal to be measured into the ion trap to cause the electric field signal to be measured and the injected and locked phonon laser to produce a mixing effect, includes:

[0108] An injection lock signal is input to the ion trap via the arbitrary wave generator 410;

[0109] Obtain the vibration frequency of the original phonon laser;

[0110] The frequency of the injection locking signal is adjusted so that the frequency of the injection locking signal is the same as the vibration frequency of the original phonon laser, thereby causing the injection locking signal to inject and lock the original phonon laser, resulting in an injection-locked phonon laser.

[0111] The electric field signal to be measured is input to the ion trap through the electric field signal port to cause the electric field signal to be measured and the injected locked phonon laser to generate a mixing effect.

[0112] Specifically, refer to Figure 5The arbitrary wave generator 410 is connected to the DC electrode of the ion trap in the vacuum cavity 110 via a CF100 lead flange on the vacuum cavity 110, generating an injection lock signal for injection lock of the original phonon laser. The fluorescence imaging detection module 500 is electrically connected to the vacuum module 100 via a test signal input port; the test signal input port is connected to the DC electrode of the ion trap via a CF100 lead flange on the vacuum cavity 110, for inputting the test signal for detection.

[0113] Reference Figure 3 Preferably, the fluorescence imaging detection module 500 includes an imaging mirror 510, a photomultiplier tube 520 (PMT), and a charge-coupled device (CCD) 530, wherein:

[0114] The imaging mirror 510 is used to image and magnify the injected locked phonon laser;

[0115] The charge-coupled device 530 is used to acquire the spontaneous emission fluorescence signal of the injected locked phonon laser through the imaging mirror, thereby monitoring the spatial position and motion state of the trapped ions;

[0116] The photomultiplier tube 520 is used to acquire the spontaneous emission fluorescence signal of the injected locked phonon laser through the imaging mirror 510 to obtain the time distribution of the spontaneous emission fluorescence signal, and then fit the time distribution of the spontaneous emission fluorescence signal to obtain the amplitude spectrum and phase spectrum of the laser to be tested.

[0117] It should also be noted that the charge-coupled device 530 and the photomultiplier tube 520 are used to collect the fluorescence from the spontaneous emission of ions, mainly from... 40 Ca + Ion electronic energy levels The spontaneous emission fluorescence, in which the charge-coupled element 530 is also used to observe the spatial position and motion state of ions, and the photomultiplier tube 520 is also used for synchronous measurement technology to detect the amplitude and phase of phonon lasers.

[0118] Reference Figure 6a and Figure 6b , Figure 6a This is a schematic diagram of a process for acquiring spontaneous emission fluorescence signals using a photomultiplier tube 520, provided in an embodiment of the present invention. Figure 6b This is a timing diagram for measuring the amplitude and phase of an injection-locked phonon laser, provided in an embodiment of the present invention. Specifically, the temporal distribution of ion spontaneous emission fluorescence is obtained using synchronous measurement technology via a 520 photomultiplier tube in the detection system and statistical ion fluorescence. The timing diagram for synchronous measurement is as follows: Figure 4As shown, after sending the start measurement command, the rising edge of the trigger signal triggers the TAC to start data acquisition. When the photomultiplier tube 520 receives a photon, it generates a TTL signal that is transmitted to the TAC to start timing. The rising edge of the synchronization signal, which is injected with the lock signal, triggers the TAC to stop timing, obtaining a data point t. When the falling edge of the trigger signal is encountered, the TAC is triggered to stop data acquisition.

[0119] In this implementation, the time distribution of the spontaneous emission fluorescence signal of the ions that generate the injected-locked phonon laser is collected and statistically analyzed using the synchronous measurement technology of the photomultiplier tube 520. Specifically, this is the change in the number of photons of the injected-locked phonon laser over a certain period of time. By curve fitting the time distribution of the spontaneous emission fluorescence signal, a fitting curve with time as the horizontal axis can be obtained, thereby obtaining the amplitude spectrum and phase spectrum of the laser to be measured.

[0120] Reference Figure 4 and Figure 5 The third embodiment of the present invention provides another weak electric field signal detection system, which corresponds to another weak electric field signal detection method provided in the fourth embodiment of the present invention. The system includes a vacuum module 100, a confinement field module 200, a laser module 300, a detection module 400, and a fluorescence imaging detection module 500.

[0121] The vacuum module 100 includes a vacuum chamber 110 and an ion pump 120; the vacuum level in the vacuum chamber 110 is maintained at 10. - 9 On the Pa level;

[0122] The trapping field module 200 includes a DC power supply 210, an RF power supply 220, and an ion trap chip 230. The ion trap chip 230 is disposed in the vacuum cavity 110. The DC power supply 210 and the RF power supply 220 are used to power the ion trap electrodes so that the ion trap chip 230 generates a stable trapping electric field.

[0123] The laser module 300 includes a photoionization laser 310, a first laser 320, a second laser 330, a red detuned acousto-optic modulator 340, a blue detuned acousto-optic modulator 350, a first isolator 370a, a second isolator 370b, a first polarization beam splitter 600a, a second polarization beam splitter 600b, a third polarization beam splitter 600c, and a fourth polarization beam splitter 600d; wherein, the first laser 320 is a 397nm laser, and the second laser 330 is an 866nm laser;

[0124] After the first laser 320 is split by the first polarization beam splitter 600a, the first laser is incident on the red detuned acousto-optic modulator 340 and the blue detuned acousto-optic modulator 350 respectively, so that the red detuned acousto-optic modulator 340 generates red detuned laser and the blue detuned acousto-optic modulator 350 generates blue detuned laser.

[0125] The second laser 330 is used to generate a cooling laser;

[0126] The photoionization laser 310, after being coupled to the optical path of the third polarization beam splitter 600c and the second laser 330, inputs trapped ions into the ion trap;

[0127] After the red-detuned acousto-optic modulator 340 and the second laser 330 are coupled through the fourth polarization beam splitter 600d, red-detuned laser and cooling laser are input into the ion trap to cool the trapped ions.

[0128] After the red detuned acousto-optic modulator 340 and the blue detuned acousto-optic modulator 350 are coupled through the second polarization beam splitter 600b, red detuned laser and blue detuned laser are input into the ion trap so that the trapped ions generate primitive phonon laser.

[0129] The detection module 400 is used to inject and lock the original phonon laser to obtain an injected and locked phonon laser, and then input the electric field signal to be measured into the ion trap so that the electric field signal to be measured and the injected and locked phonon laser will have a mixing effect.

[0130] The detection module 400 includes an arbitrary wave generator 410 and a signal port for the electric field to be measured. The arbitrary wave generator 410 inputs an injection locking signal to the ion trap, thereby injecting and locking the original phonon laser to obtain an injection-locked phonon laser.

[0131] The electric field signal to be measured is input to the ion trap through the electric field signal port to cause the electric field signal to be measured and the injected locked phonon laser to generate a mixing effect.

[0132] The fluorescence imaging detection module 500 is used to acquire the amplitude spectrum and phase spectrum of the injected locked phonon laser, and then analyze the amplitude spectrum and phase spectrum of the laser under test based on a preset phonon laser-electric field signal model to obtain the test information of the electric field signal under test.

[0133] The fluorescence imaging detection module 500 includes an imaging mirror 510, a photomultiplier tube 520, a charge-coupled element 530, and a fifth polarization beam splitter 600e.

[0134] After the imaging mirror 510 images and magnifies the injected locked phonon laser, it is split by the fifth polarization beam splitter 600e, thereby inputting the injected locked phonon laser into the photomultiplier tube 520 and the charge-coupled device 530 respectively.

[0135] The photomultiplier tube 520 is used to acquire the spontaneous emission fluorescence signal of the injected locked phonon laser through the imaging mirror 510 to obtain the time distribution of the spontaneous emission fluorescence signal, and then fit the time distribution of the spontaneous emission fluorescence signal to obtain the amplitude spectrum and phase spectrum of the laser to be tested.

[0136] It should be noted that the ion trap is used to trap... Ions form single-ion phonon lasers under the action of blue detuned lasers, and a locking signal is injected. and the signal to be measured Under the influence of the phonon laser, the equation of motion can be written as follows:

[0137]

[0138] in For ion mass, and These represent the forces exerted on ions by red detuned lasers and blue detuned lasers, respectively. The forces exerted on the ions include implantation locking and the signal to be measured, wherein, The detuning between the signal under test and the injected lock signal. and Here, represents the intensity of the injected lock signal and the signal under test, respectively, and e represents the unit charge. The parameters introduced for the ion trap electrodes. Under the action of the injection lock signal, the ion displacement can be written as having a frequency along the z-direction of the ion trap. The simple harmonic motion is shown in the following equation:

[0139]

[0140] in denoted as the trap frequency in the z-direction of the ion trap. and Let be the slowly varying amplitude and phase of the ion at time t, respectively. Substituting the above equation into the equation of motion for the phonon laser yields the following equation:

[0141]

[0142] Using the slow variation approximation, simplifying the above equation and retaining only the main derivative terms, we obtain the following equation:

[0143]

[0144] Since the injection lock frequency is set to be the same as the trap frequency in the z-direction of the ion trap, that is... Therefore, the above equation can be further simplified to the following equation:

[0145]

[0146] Multiply both sides of the equation by . and And by integrating both sides of the equation over one vibration period, the amplitude term in the equation of motion of the phonon laser is obtained. and phase term Separating the parts, we can obtain the following formula:

[0147]

[0148]

[0149] in This represents the average value of the ions over a sufficiently long time. Using the slow-varying approximation, the amplitude and phase of the phonon laser can be further simplified to the following equation:

[0150]

[0151]

[0152] Consider a scenario where only a lock signal is injected, and no signal under test is detected. When the injected and locked phonon laser is in a stable simple harmonic oscillation state, the amplitude and phase of the phonon laser remain constant, as shown in the following equation:

[0153]

[0154]

[0155] Since the frequency of the injection lock signal is the same as the trap frequency. According to the principle of injection locking, we can obtain The above equation can be further simplified to the following equation:

[0156]

[0157]

[0158] Therefore, under the influence of the injection lock signal and the signal to be measured, the changes in the amplitude and phase of the phonon laser can be written as follows:

[0159]

[0160]

[0161] because And the strength of the signal to be measured Much smaller than the injection lock strength The effect of the signal under test on the injected and locked phonon laser can be regarded as a perturbation term, i.e. Therefore, we can obtain the changes in the amplitude and phase of the phonon laser as shown in the following equation:

[0162]

[0163]

[0164] Integrating the above equation, we can obtain the equation that satisfies the boundary conditions. , The amplitude and phase of the phonon laser are shown in the following equation:

[0165]

[0166]

[0167] As can be seen, the injection-locking effect of the phonon laser achieves the mixing and filtering processes between the injected-locked signal and the signal under test. The mixed and filtered phase-locked signal is reflected in the amplitude and phase of the phonon laser, two orthogonal physical quantities. Therefore, the injected-locked phonon laser can be used as a two-phase lock-in amplifier, with its amplitude and phase serving as its two branches, simultaneously used for two-phase lock-in measurement of the signal under test. After the signal under test is converted into an electrical signal, it is input to the ion trap electrode and acts on the injected-locked single-ion phonon laser. The signal under test simultaneously causes periodic changes in the amplitude and phase of the phonon laser over time. By measuring the real-time changes in the amplitude and phase of the phonon laser, two-phase lock-in measurement of the frequency, amplitude, and phase of the signal under test can be achieved.

[0168] Reference Figure 4 and Figure 5 The fourth embodiment of the present invention provides another method for detecting weak electric field signals, which corresponds to the third embodiment of the present invention for detecting weak electric field signals. The method includes the following steps:

[0169] Step 1: Generate an injection-locked phonon laser.

[0170] The vacuum chamber 110 is maintained at 10 using the ion pump 120. -9 In an ultra-high vacuum environment (Pa), calcium atoms ejected from the atomic furnace are ionized by a photoionization laser in laser module 300 to generate… 40 Ca +Ions are loaded into a three-dimensional trapping potential well (i.e., the ion trap) generated on the electrode surface of the ion trap chip 230 in the vacuum cavity 110. The output light of the 397nm laser is incident on the first isolator 370a, and the output light of the 866nm laser is incident on the second isolator 370b. The 397nm light emitted from the first isolator 370a is transmitted through the first polarization beam splitter 600aPBS and then outputs a red-detuned laser through the red-detuned acousto-optic modulator 340. The 866nm laser emitted from the second isolator 370b and the red-detuned laser are coupled together through the third polarization beam splitter 600c and the fourth polarization beam splitter 600d into an optical fiber and input to the ion trap located in the vacuum cavity 110 for cooling. 40 Ca + Ions, to achieve 40 Ca + Stable trapping of ions. The 397nm light emitted from the first isolator 370a is reflected by the first polarization beam splitter 600a and incident on the blue detuned acousto-optic modulator 350 to output blue detuned laser. The blue detuned laser and the red detuned laser are coupled into the optical fiber through the second polarization beam splitter 600b and then input into the ion trap located in the vacuum cavity 110, where they act on the cooled ions to generate phonon laser.

[0171] An arbitrary wave generator 410 (AWG) generates a frequency that corresponds to the ion trap frequency. A sinusoidal signal of the same frequency is used as the injection-lock signal and input into the ion trap electrode to induce injection-locking of the phonon laser. Experimentally, the phonon laser amplitude is adjusted to a suitable value; in this embodiment, the injection-locking intensity is selected as [value missing]. At this time, the phonon laser amplitude observed from the charge-coupled device 530 is approximately .

[0172] Step 2: Simultaneous measurement technology measures the real-time amplitude and phase information of the phonon laser.

[0173] The amplitude and phase of a single-ion phonon laser under injection lock-in can affect the spontaneous emission rate of the ions. By using synchronous measurement technology and statistically analyzing the time distribution of the spontaneous emission fluorescence signal of the ions with a photomultiplier tube 520, the spontaneous emission rate of the ions can be obtained. By fitting the measured time distribution of the spontaneous emission fluorescence signal of the ions, the real-time amplitude and phase information of the phonon laser can be obtained. Figure 7 To simultaneously measure the temporal distribution and fitting results of the acquired ion spontaneous emission fluorescence signal, the amplitude and phase of the corresponding phonon laser are respectively... and rad.

[0174] Step 3: Input a standard electric field signal and measure the periodic variation of the phonon laser amplitude and phase over time.

[0175] A sinusoidal signal with a frequency close to the injection lock frequency is generated by an arbitrary wave generator 410 and input as a standard electric field signal into the ion trap electrode. When the phonon laser is subjected to an electric field signal with a frequency close to the injection lock signal, the amplitude and phase of the phonon laser will change accordingly in real time. Using synchronous measurement technology, the amplitude and phase information of the phonon laser can be obtained by analyzing the spontaneous emission fluorescence signal of the ions collected by the photomultiplier tube 520. In this embodiment, the synchronous measurement sampling rate is 1 Sa / s, and the total sampling time is 20 s.

[0176] The selected parameters for this embodiment are: detuning between the calibration signal and the injection lock signal is 0.1 Hz, the strength of the signal under test is 75 mV, and the initial phase of the signal under test is... By fitting the spontaneous emission fluorescence signal of ions obtained from synchronous measurements, the periodic variation of the amplitude and phase of the phonon laser with time was obtained as follows: Figure 8 As shown.

[0177] Step 4: Calibrate the relationship between the periodic variation of phonon laser amplitude and phase over time and the electric field signal parameters.

[0178] Changing the frequency, amplitude, and phase of the input standard electric field signal alters the real-time variation of the phonon laser amplitude and phase accordingly. Figure 9 , Figure 10 and Figure 11 The frequency, amplitude, and phase variation patterns of the phonon laser amplitude and phase versus the measured signal are shown. It can be seen that the detuning between the standard electric field signal and the injection lock signal is equal to the period of the time-varying amplitude and phase of the phonon laser. The phase of the standard electric field signal is equal to the initial phase of the time-varying amplitude and phase of the phonon laser. The amplitude of the standard electric field signal is proportional to the amplitude of the time-varying amplitude and phase of the phonon laser.

[0179] Step 5: Measure the electric field signal to be measured.

[0180] The electric field signal to be measured is input into the ion trap electrode. According to the synchronous measurement technique in step 2, the real-time amplitude and phase changes of the phonon laser are measured. By comparing the relationship between the phonon laser amplitude and phase fluctuation law with the electric field signal parameters obtained in step 4, the two-phase lock-in measurement of the frequency, amplitude and phase of the electric field signal to be measured can be realized.

[0181] The weak electric field signal detection method and system provided by the present invention have at least the following advantages compared with the prior art:

[0182] This invention utilizes the injection-locking principle of single-ion phonon lasers and employs synchronous measurement technology to measure the amplitude and phase of the phonon laser, achieving two-phase lock-in measurement of weak electric field signals. It can obtain the frequency, amplitude, and phase information of the signal under test in a single measurement, providing a solution to the problem of large demodulation errors caused by the deviation in the received signal by the two mixers due to circuit phase noise in traditional two-phase lock-in amplifiers. Specifically, the injection-locked phonon laser senses an additional electric field signal with a frequency close to the injection-locking frequency. The injection-locking effect acts as a mixer, superimposing the additional electric field signal and the mixed signal of the injection-locking signal onto the simple harmonic oscillation of the phonon laser. Therefore, by using the injection-locked single-ion phonon laser as a two-phase lock-in amplifier, and by measuring the motion state of the phonon laser, complete information on the frequency, amplitude, and phase of the signal under test can be obtained simultaneously in a single measurement. The two paths of the dual-phase lock-in amplifier are obtained from the amplitude and phase information of the phonon laser, respectively. Therefore, compared with the traditional dual-phase lock-in amplifier, the two paths of the single-ion lock-in amplifier give it the outstanding characteristics of low detection error and high frequency resolution.

[0183] Detection in specific embodiments shows that, from Figure 9 , Figure 10 and Figure 11 The results show that the frequency, phase, and amplitude information of the signal under test can be obtained from the changes in the amplitude and phase of the phonon laser, proving the effectiveness and reliability of using injected locked phonon laser for two-phase lock-in measurement to detect the signal under test.

[0184] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0185] The term "embodiment" as used herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described; however, any combination of these technical features that does not contradict each other should be considered within the scope of this specification.

[0186] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various improvements and substitutions without departing from the concept of this application, and these improvements and substitutions should also be considered within the scope of protection of this invention. Therefore, the scope of protection of this application should be determined by the appended claims.

Claims

1. A method of detecting a weak electric field signal, characterized by, The method comprises the following steps: generating an ion trap in a preset vacuum cavity; generating a primary phonon laser in the ion trap; injectively locking the primary phonon laser to obtain an injectively locked phonon laser; inputting a to-be-detected electric field signal into the ion trap to make the to-be-detected electric field signal and the injectively locked phonon laser generate a mixing action; obtaining a to-be-detected laser amplitude spectrum and a to-be-detected laser phase spectrum of the injectively locked phonon laser, comprising: obtaining a spontaneous emission fluorescence signal of the injectively locked phonon laser, and then obtaining a time distribution of the spontaneous emission fluorescence signal; curve fitting the time distribution of the spontaneous emission fluorescence signal to obtain the to-be-detected laser amplitude spectrum and the to-be-detected laser phase spectrum; analyzing the to-be-detected laser amplitude spectrum and the to-be-detected laser phase spectrum based on a preset phonon laser-electric field signal model to obtain a frequency, an amplitude and a phase of the to-be-detected electric field signal, comprising: inputting a plurality of standard electric field signals with different frequencies, amplitudes and phases into the ion trap respectively, and then obtaining a standard laser amplitude spectrum and a standard laser phase spectrum of the injectively locked phonon laser corresponding to each of the standard electric field signals; constructing a phonon laser-electric field signal model based on each of the standard electric field signals and the standard laser amplitude spectrum and the standard laser phase spectrum corresponding to each of the standard electric field signals, comprising: calibrating real-time variation rules of amplitudes and phases of the injectively locked phonon laser corresponding to the standard electric field signals with different frequencies, amplitudes and phases, constructing a functional relationship between the frequencies, amplitudes and phases of the input standard electric field signals and the amplitude spectrum and the phase spectrum of the injectively locked phonon laser, and thus obtaining the phonon laser-electric field signal model.

2. The method of claim 1, wherein the method comprises: The method further comprises the following steps for generating the primary phonon laser in the ion trap: inputting a trapped ion into the ion trap; inputting a red-detuned laser and a cooling laser into the ion trap to cool the trapped ion; inputting a red-detuned laser and a blue-detuned laser into the ion trap to make the trapped ion generate a primary phonon laser.

3. The method of claim 1, wherein the method comprises: The method further comprises the following steps for injectively locking the primary phonon laser to obtain the injectively locked phonon laser: inputting an injectively locked signal into the ion trap; obtaining a vibration frequency of the primary phonon laser; adjusting a frequency of the injectively locked signal to make the frequency of the injectively locked signal the same as the vibration frequency of the primary phonon laser, so that the injectively locked signal generates an injectively locking action on the primary phonon laser to obtain the injectively locked phonon laser.

4. A weak electric field signal detection system characterized by, The system is used for implementing the method for detecting a weak electric field signal according to any one of claims 1 to 3, and the system comprises a vacuum module, a trapped field module, a laser module, a detection module and a fluorescence imaging detection module, wherein: the vacuum module comprises a vacuum cavity and an ion pump, and the ion pump is used for maintaining a vacuum degree of the vacuum cavity; the trapped field module is used for generating an ion trap in the vacuum cavity; the laser module comprises a photoionization laser, a first laser, a second laser, a red-detuned acousto-optic modulator and a blue-detuned acousto-optic modulator, wherein: the photoionization laser is used for inputting a trapped ion into the ion trap; The first laser is configured to respectively irradiate the red-detuned acousto-optic modulator and the blue-detuned acousto-optic modulator with first laser light, so that the red-detuned acousto-optic modulator generates red-detuned laser light and the blue-detuned acousto-optic modulator generates blue-detuned laser light; The second laser is configured to generate cooling laser light; The red-detuned acousto-optic modulator and the second laser are further configured to input the red-detuned laser light and the cooling laser light into the ion trap, so as to cool the trapped ions. The red-detuned acousto-optic modulator and the blue-detuned acousto-optic modulator are further configured to input the red-detuned laser light and the blue-detuned laser light into the ion trap, so as to make the trapped ions generate original phonon laser light. The detection module is configured to injection-lock the original phonon laser light, so as to obtain injection-locked phonon laser light, and then input a to-be-detected electric field signal into the ion trap, so that the to-be-detected electric field signal and the injection-locked phonon laser light generate a mixing action. The fluorescence imaging detection module is configured to obtain a to-be-detected laser amplitude spectrum and a to-be-detected laser phase spectrum of the injection-locked phonon laser light, and then analyze the to-be-detected laser amplitude spectrum and the to-be-detected laser phase spectrum based on a preset phonon laser-electric field signal model, so as to obtain to-be-detected information of the to-be-detected electric field signal. The fluorescence imaging detection module comprises an imaging lens, a charge-coupled device, and a photomultiplier tube, wherein: The imaging lens is configured to image and amplify the injection-locked phonon laser light. The charge-coupled device is configured to obtain a spontaneous emission fluorescence signal of the injection-locked phonon laser light through the imaging lens, and then monitor a spatial position and a motion state of the trapped ions. The photomultiplier tube is configured to obtain the spontaneous emission fluorescence signal of the injection-locked phonon laser light through the imaging lens, so as to obtain a time distribution of the spontaneous emission fluorescence signal, and then fit the time distribution of the spontaneous emission fluorescence signal, so as to obtain the to-be-detected laser amplitude spectrum and the to-be-detected laser phase spectrum.

5. A weak electric field signal detection system according to claim 4, wherein The trapping field module comprises a direct current power supply, a radio frequency power supply, and an ion trap chip, wherein the ion trap chip is arranged in the vacuum cavity; and The direct current power supply and the radio frequency power supply are configured to supply power to the ion trap chip, so that the ion trap chip generates an ion trap in the vacuum cavity.

6. The weak electric field signal detection system of claim 4, wherein, The detection module comprises an arbitrary wave generator and a to-be-detected electric field signal port, and the injection-locking of the original phonon laser light, the obtaining of the injection-locked phonon laser light, the inputting of the to-be-detected electric field signal into the ion trap, and the mixing action of the to-be-detected electric field signal and the injection-locked phonon laser light comprise the following steps: The arbitrary wave generator is configured to input an injection-locked signal into the ion trap; A vibration frequency of the original phonon laser light is obtained; The frequency of the injection-locked signal is adjusted to be the same as the vibration frequency of the original phonon laser light, so that the injection-locked signal injection-locks the original phonon laser light to obtain injection-locked phonon laser light; The to-be-detected electric field signal port is configured to input a to-be-detected electric field signal into the ion trap, so that the to-be-detected electric field signal and the injection-locked phonon laser light generate a mixing action.

Images