Power frequency voltage quantum measurement device based on Rydberg atoms

Abstract

The invention relates to the technical field of metering, and discloses a power frequency voltage quantum measurement device based on Rydberg atoms, which comprises an electric field-voltage introduction device used for accessing to-be-measured voltage, generating a uniform electric field, receiving modulated detection light and coupling light, and outputting the modulated detection light and coupling light to the electric field-voltage introduction device; the modulated detection light and the coupled light are reversely overlapped and input into an atom gas chamber with cesium atoms, and the cesium atoms are excited to be in a Rydberg state; the electric field quantum measurement light path system based on the Rydberg atoms is used for receiving and modulating the detection light and the coupling light, generating modulated detection light and coupling light, reversely overlapping the modulated detection light and coupling light, inputting the modulated detection light and coupling light into the atom gas chamber with the cesium atoms, and generating an electric signal corresponding to a detection spectrum after the detection light acts with the detected electric field and the cesium Rydberg atoms; the signal processing system is used for receiving the electric signal corresponding to the detection spectrum, performing filtering processing, and performing feature extraction and electric field and voltage inversion on the filtered signal to obtain a to-be-detected voltage; according to the invention, the measurement precision of the to-be-measured voltage is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metrology, and particularly to a quantum measurement device for power frequency voltage based on Rydberg atoms. Background Art

[0002] Accurate voltage measurement is crucial for the safe and stable operation of power equipment and systems, and is also related to power economy, energy conservation and emission reduction. Due to the inherent defects of the sensing mechanisms of traditional electromagnetic and electronic / photoelectric voltage transformers, it is difficult to achieve breakthroughs in measurement performance. In recent years, the emerging quantum measurement uses the quantum effects generated by the interaction between a specific atomic energy level system and the physical quantity to be measured to achieve high-performance measurement of physical quantities. Especially, since the atomic parameters and energy levels are fixed, quantum measurement has self-calibration properties, leading to the revolution of a new generation of sensors. Among them, Rydberg atoms (collectively referred to as highly excited state atoms with only one outermost electron and a relatively high principal quantum number n) have a series of excellent physical properties, which are particularly suitable for the measurement of electric fields; in the power system, the voltage generates a corresponding regular distribution of electric fields in the surrounding space, and the quantum effect is extremely sensitive to the spatial electric field. This quantum effect provides a sensing principle with better performance for voltage measurement, and new technical means for high-precision voltage measurement can be developed. In recent years, significant breakthroughs have been made in the measurement of weak microwave fields based on the Electromagnetically Induced Transparency (EIT) effect and Autler-Townes (AT) effect of Rydberg atoms; the above-mentioned microwave frequency is the resonance frequency of atomic energy level transitions. However, the electric field generated by the power frequency voltage in the power system has characteristics such as low frequency and high intensity, which are completely different from microwaves. The existing microwave electric field measurement principles and technologies based on Rydberg atoms cannot be simply transplanted. Summary of the Invention

[0003] Aiming at the above deficiencies in the prior art, the present invention provides a quantum measurement device for power frequency voltage based on Rydberg atoms. By proposing a targeted power frequency voltage measurement device, it is used to solve the problems that the existing microwave electric field measurement principles and technologies based on Rydberg atoms cannot be simply transplanted and the power frequency voltage measurement accuracy is inaccurate.

[0004] In order to achieve the above invention purpose, the technical solution adopted by the present invention is as follows:

[0005] A quantum measurement device for power frequency voltage based on Rydberg atoms, comprising:

[0006] An electric field-voltage introduction device, which is used to connect to the voltage to be measured and generate a uniform electric field, and at the same time receive the modulated probe light and coupling light, and input the modulated probe light and coupling light in the opposite direction and coincide them into an atomic cell containing cesium atoms to excite the cesium atoms to the Rydberg state, generating cesium Rydberg atoms;

[0007] An optical path system for quantum measurement of electric field based on Rydberg atoms is used to receive probe light and coupling light and perform modulation, generate modulated probe light and coupling light and input them in reverse and coincide into an atomic cell with cesium atoms. After the probe light interacts with the measured electric field and cesium Rydberg atoms, an electric signal corresponding to the probe spectrum is generated;

[0008] A signal processing system is used to receive the electric signal corresponding to the probe spectrum and perform filtering processing, and obtain the voltage to be measured by extracting features, inverting the electric field and voltage on the filtered signal.

[0009] The present invention has the following beneficial effects:

[0010] A power frequency voltage quantum measurement device based on Rydberg atoms proposed by the present invention generates a uniform electric field according to the measured power frequency voltage, generates a high-quality spectrum reflecting the interaction effect of the electric field and cesium Rydberg atoms through laser and optical path modulation, and performs signal processing to improve the measurement accuracy of the measured power frequency voltage. Brief Description of the Drawings

[0011] Figure 1 It is a schematic structural diagram of a power frequency voltage quantum measurement device based on Rydberg atoms proposed by the present invention;

[0012] Figure 2 It is a schematic structural diagram of a voltage-electric field introduction device in the embodiment;

[0013] Figure 3 It is a schematic diagram of the electric field distribution effect of a circular electrode plate in the embodiment;

[0014] Figure 4 It is a schematic diagram of the electric field distribution effect of a square electrode plate in the embodiment;

[0015] Figure 5 It is a schematic structural diagram of an optical path system for quantum measurement of electric field based on Rydberg atoms in the embodiment;

[0016] Figure 6 It is a schematic diagram of the spectral result of obtaining 28D 5 / 2 Rydberg atoms by using the optical path system for quantum measurement of electric field based on Rydberg atoms and the voltage-electric field introduction device in the embodiment;

[0017] Figure 7 It is a schematic diagram of the optical peak recognition result obtained by the signal processing system in the embodiment. Detailed Embodiments

[0018] The specific embodiments of the present invention will be described below to facilitate those skilled in the art of the present technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions created using the concept of the present invention are within the scope of protection.

[0019] As Figure 1 shown, a power frequency voltage quantum measurement device based on Rydberg atoms includes:

[0020] An electric field-voltage introduction device for accessing the voltage to be measured and generating a uniform electric field, and at the same time receiving the modulated probe light and coupling light, and inputting the modulated probe light and coupling light in reverse coincidence into an atomic cell containing cesium atoms to excite the cesium atoms to the Rydberg state and generate cesium Rydberg atoms.

[0021] As Figure 2 shown, Figure 2 shows the structure and connection relationship of the voltage-electric field introduction device, including a first circular electrode plate and a second circular electrode plate of equal size placed inside the electric field shielding box at a set insulation distance, a voltage lead, and an atomic cell. The bottom of the electric field shielding box is grounded and both the inner and outer walls are coated with insulating paint. The voltage lead passes through the electric field shielding box through a sleeve perforation and is connected to the first circular electrode plate. The atomic cell is placed equidistantly between the first circular electrode plate and the second circular electrode plate, and the two ends of the atomic cell coincide in reverse at the circular electrode plate; when the voltage to be measured acts on the first circular electrode plate through the voltage lead, a uniform electric field is generated between the first circular electrode plate and the second circular electrode plate, and at the same time, the modulated probe light and coupling light pass through the two ends of the electric field shielding box in reverse coincidence and enter the atomic cell containing cesium atoms.

[0022] In this embodiment, the voltage to be measured is applied to the first circular electrode plate and the second circular electrode plate to generate an electric field between the plates. The first circular electrode plate and the second circular electrode plate are both copper metal electrode plates and are circular to avoid the electric field distortion at the right-angle position of the rectangular electrode plate. As Figures 3 - 4 shown, Figures 3 - 4 respectively show the electric field distribution effects of the circular electrode plate and the square electrode plate. The areas of the circular electrode plate and the square electrode plate are basically the same, the distance between the two plates is the same, and the same voltage is applied at the same time. From Figures 3 - 4 it can be seen that the electric field distortion at the right angle of the square electrode increases, and the maximum value is 4.5 times higher than that at the edge of the circular electrode; while the electric field at the edge of the circular electrode is evenly distributed, so the spatial electric field distribution between the two plates is also more uniform than the electric field generated by the square electrode.

[0023] Specifically, the set insulation distance is greater than or equal to 30 cm.

[0024] In this embodiment, a copper plate is used to make the electric field shielding box, and the bottom is grounded to shield other electric field interferences in the environment. At the same time, insulating coatings are applied to the inner and outer walls of the shielding box, and the insulation distance between the shielding box body and the electrode plate is ≥ 30 cm.

[0025] Specifically, when the voltage to be measured acts on the first circular electrode plate through the voltage lead wire, a uniform electric field is generated between the first circular electrode plate and the second circular electrode plate. At this time, the radius of the first circular electrode plate or the second circular electrode plate and the distance between the circular electrode plates satisfy the following relationship:

[0026]

[0027] where r represents the radius of the first circular electrode plate or the second circular electrode plate, and d represents the distance between the circular electrode plates.

[0028] In this embodiment, the radius of the first circular electrode plate or the second circular electrode plate and the distance between the circular electrode plates are set to The purpose is to ensure a uniform distribution of the electric field at the position of the atomic gas chamber between the plates.

[0029] Specifically, the relationship between the uniform electric field and the voltage to be measured is:

[0030]

[0031] where E(t) represents the uniform electric field at the t-th moment, and u(t) represents the voltage to be measured at the t-th moment.

[0032] In addition, limited by the equipment size and considering insulation safety, this voltage-electric field introduction device is applicable to medium and low voltage levels of 35 kV and below.

[0033] The optical path system for electric field quantum measurement based on Rydberg atoms is used to receive the probe light and the coupling light and perform modulation, generate the modulated probe light and coupling light and input them in reverse coincidence into the atomic gas chamber containing cesium atoms. After the probe light acts on the measured electric field and cesium Rydberg atoms, an electric signal corresponding to the probe spectrum is generated.

[0034] As Figure 5 shown, Figure 5 shows the structure and connection relationship of the optical path system for electric field quantum measurement based on Rydberg atoms, including a single-frequency fiber laser and its frequency stabilization control system module, a first single-mode fiber, a second single-mode fiber, a first collimator, a second collimator, a third collimator, a first half-wave plate, a second half-wave plate, a third half-wave plate, a first polarization beam splitter prism, a second polarization beam splitter prism, a first optical trash can, a second optical trash can, a third optical trash can, a mirror, a first dichroic mirror, a second dichroic mirror, a third single-mode fiber, and a photoelectric converter.

[0035] The single-frequency fiber laser and its frequency stabilization control system module emit probe light and coupled light, and perform frequency stabilization processing; the frequency-stabilized probe light and coupled light are respectively input into the first collimator and the second collimator through the first single-mode fiber and the second single-mode fiber; the first collimator and the second collimator respectively emit the probe light and the coupled light in the form of spatial light and align them with the first half-wave plate and the second half-wave plate; after the first half-wave plate and the second half-wave plate respectively adjust the powers of the probe light and the coupled light, they input them into the first polarization beam splitter prism and the second polarization beam splitter prism; the first polarization beam splitter prism and the second polarization beam splitter prism respectively input the vertically polarized light of the probe light and the coupled light into the mirror and the third half-wave plate, and input the horizontally polarized light of the probe light and the coupled light into the first optical trash can and the second optical trash can; the probe light passing through the mirror is input into the first two-phase prism and then horizontally input into the atomic cell; and the polarization angle of the coupled light is adjusted by the third half-wave plate to keep the polarization angle of the coupled light parallel to the polarization angle of the probe light; and the coupled light is input into the second two-phase prism to adjust the transmission direction of the coupled light to keep the coupled light and the probe light pass through the atomic cell in the opposite direction and coincide; the coupled light and the probe light act on the atomic cell with cesium atoms at the same time, so that the cesium atoms transition from the ground state |6S 1 / 2 > to the Rydberg state |28D 5 / 2 >, and the probe light and the coupled light have an electromagnetically induced transparency effect with the cesium Rydberg atoms in the atomic cell, generating an EIT light peak; when the uniform electric field generated by the voltage-electric field introducing device acts on the cesium Rydberg atoms in the atomic cell, the Stark effect is generated, and the frequency position of the EIT light peak is shifted, generating a Stark frequency shift, and generating a Stark frequency shift amount; and after the Stark frequency shift, the coupled light is input into the first dichroic mirror from the atomic cell and enters the third optical trash can, and at the same time the probe light is input into the second dichroic mirror from the atomic cell, passes through the third collimator and the single-mode fiber, generates the probe light after interacting with the electric field and the cesium Rydberg atoms, and inputs it into the photoelectric converter to convert the transmitted probe light signal into an electrical signal.

[0036] Specifically, the wavelength of the probe light emitted by the single-frequency fiber laser and its frequency stabilization control system module is 852.347 nm.

[0037] In this embodiment, a two-photon (probe light and coupled light) ladder-type three-level excitation structure is adopted, and the probe light with a wavelength of 852.347 nm is selected to excite the cesium atoms from the ground state |6S 1 / 2 > to the first excited state |6P 3 / 2 .

[0038] Specifically, the central wavelength of the coupled light emitted by the single-frequency fiber laser and its frequency stabilization control system module is 512.667 nm, and it can be frequency-swept within the range of ±1 GHz.

[0039] In this embodiment, in order to measure strong electric fields above the kV / m level, the principal quantum number n of the Rydberg state is selected as 28, and the corresponding central wavelength of the coupling light is 512.667, and it can be frequency-swept within the range of ±1 GHz. The advantages of such a design are as follows: Only by frequency-sweeping the coupling light with a certain central wavelength and inputting it can an EIT peak (in the form of a single peak) be formed; in addition, the larger the frequency-sweeping range, the larger the field strength value of the measurable electric field.

[0040] As Figure 6 shown, Figure 6 it shows the spectral results of obtaining 28D 5 / 2 state Rydberg atoms by using the optical path system for quantum measurement of electric fields based on Rydberg atoms and the voltage-electric field introduction device. Among them, Figure 6 the abscissa is the frequency detuning amount (Δ c ) of the coupling light. As can be seen from Figure 6 , when there is no external electric field, the probe light and the coupling light act on cesium Rydberg atoms to generate an EIT spectrum in the form of a single peak. This EIT spectrum has a relatively high peak value and a narrow linewidth. And as the field strength of the acting electric field increases, the three degenerate states (mj = 1 / 2, 3 / 2, 5 / 2) of the 28D 5 / 2 state Rydberg atoms gradually split out to form corresponding small peaks, and at the same time, they are frequency-shifted outward relative to the EIT light peak position in the zero-field state. Therefore, by using the optical path system for quantum measurement of electric fields of Rydberg atoms proposed in the present invention, a spectrum with excellent quality can be obtained.

[0041] The signal processing system is used to receive the electrical signal corresponding to the detection spectrum and perform filtering processing, and obtain the voltage to be measured by performing feature extraction, electric field and voltage inversion on the filtered signal.

[0042] Specifically, the process of the signal processing system for receiving the electrical signal corresponding to the detection spectrum, performing filtering processing, and obtaining the voltage to be measured by performing feature extraction, electric field and voltage inversion on the filtered signal is as follows:

[0043] First, receive the electrical signal corresponding to the detection spectrum and perform low-pass filtering to generate a filtered signal.

[0044] In this embodiment, the purpose of low-pass filtering is to eliminate high-frequency noise in the electrical signal corresponding to the detection spectrum.

[0045] Secondly, use the wavelet transform method to identify the Stark splitting peaks of the filtered signal, and extract the frequency positions of the Stark splitting peaks to generate the Stark frequency shift amount.

[0046] At the same time, according to the Stark frequency shift amount, calculate the uniform electric field, that is:

[0047]

[0048] where α i represents the polarizability in the i-th energy level eigenstate, and ΔStark represents the Stark frequency shift amount;

[0049] Finally, according to the uniform electric field, the electric field to be measured is calculated, that is:

[0050] u(t) = E(t)d

[0051] In this embodiment, Figure 7 the optical peak recognition result obtained by the signal processing system is shown. From Figure 7 it can be seen that by performing low-pass filtering on the electrical signal corresponding to the spectrum and using the wavelet transform method to recognize the optical peak, the peak positions of each Stark split peak can be accurately recognized.

[0052] In summary, a power frequency voltage quantum measurement device based on Rydberg atoms proposed by the present invention generates a uniform electric field according to the measured power frequency voltage, generates a high-quality spectrum reflecting the interaction effect of the electric field and cesium Rydberg atoms through laser and optical path modulation, and performs signal processing to improve the measurement accuracy of the measured power frequency voltage.

[0053] In the present invention, specific embodiments are applied to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

[0054] Those of ordinary skill in the art will realize that the embodiments here are for helping readers understand the principle of the present invention, and it should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those of ordinary skill in the art can make various other specific deformations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed in the present invention, and these deformations and combinations are still within the protection scope of the present invention.

Claims

1. A power frequency voltage quantum measurement device based on Rydberg atoms, characterized in that: include: An electric field-voltage introduction device is used to connect the voltage to be measured and generate a uniform electric field, and simultaneously receive the modulated detection light and the coupling light, and input the modulated detection light and the coupling light into the atomic gas chamber where cesium atoms exist in reverse overlap, so as to excite the cesium atoms to the Rydberg state and generate cesium Rydberg atoms; The electric field quantum measurement optical path system based on Rydberg atoms is used to receive and modulate the detection light and the coupling light, generate modulated detection light and coupling light, and input the modulated detection light and coupling light into the atomic gas chamber where cesium atoms exist in reverse overlap, and after the detection light interacts with the measured electric field and cesium Rydberg atoms, an electrical signal corresponding to the detection spectrum is generated; The signal processing system is used to receive the electrical signal corresponding to the detection spectrum and perform filtering processing, and obtain the voltage to be measured by performing feature extraction, electric field and voltage inversion on the filtered signal.

2. The power frequency voltage quantum measurement device based on Rydberg atoms according to claim 1, characterized in that: The voltage-electric field introduction device comprises a first circular electrode plate and a second circular electrode plate of equal size and placed inside an electric field shielding box at a set insulation distance, a voltage lead, and an atomic gas chamber. The bottom of the electric field shielding box is grounded and the inner and outer walls are coated with insulating paint. The voltage lead passes through the casing through the hole of the electric field shielding box and is connected to the first circular electrode plate. The atomic gas chamber is equidistantly placed between the first circular electrode plate and the second circular electrode plate, and the two ends of the atomic gas chamber are reversely overlapped with the circular electrode plates. When the voltage to be measured acts on the first circular electrode plate through the voltage lead, a uniform electric field is generated between the first circular electrode plate and the second circular electrode plate, and at the same time, the modulated detection light and the coupling light perforate through the two ends of the electric field shielding box and overlap in reverse to enter the atomic gas chamber where cesium atoms exist.

3. The power frequency voltage quantum measurement device based on Rydberg atoms according to claim 2, characterized in that: The insulation distance is set to be greater than or equal to 30cm.

4. The Rydberg atom-based power frequency voltage quantum measurement device according to claim 3, characterized in that: When the voltage to be measured acts on the first circular electrode plate through the voltage lead, a uniform electric field is generated between the first circular electrode plate and the second circular electrode plate. At this time, the radius of the first circular electrode plate or the second circular electrode plate and the distance between the circular electrode plates satisfy the following relationship: Wherein, r represents the radius of the first circular electrode plate or the second circular electrode plate, and d represents the distance between the circular electrode plates.

5. The Rydberg atom-based power frequency voltage quantum measurement device according to claim 4, characterized in that: The uniform electric field and the voltage to be measured satisfy the following relationship: Wherein, E(t) represents the uniform electric field at the tth moment, and u(t) represents the voltage to be measured at the tth moment.

6. The Rydberg atom-based power frequency voltage quantum measurement device according to claim 5, characterized in that: The electric field quantum measurement optical path system based on Rydberg atoms includes a single-frequency fiber laser and a frequency stabilization control system module thereof, a first single-mode fiber, a second single-mode fiber, a first collimator, a second collimator, a third collimator, a first half-wave plate, a second half-wave plate, a third half-wave plate, a first polarization beam splitter prism, a second polarization beam splitter prism, a first optical trash can, a second optical trash can, a third optical trash can, a reflector, a first dichroic mirror, a second dichroic mirror, a third single-mode fiber, and a photoelectric converter; A single-frequency fiber laser and a frequency stabilization control system module thereof emit detection light and coupling light, and perform frequency stabilization processing; the detection light and coupling light subjected to frequency stabilization are input into a first collimator and a second collimator through a first single-mode optical fiber and a second single-mode optical fiber respectively; the first collimator and the second collimator respectively align the detection light and coupling light in the form of spatial light to a first half-wave plate and a second half-wave plate and emit them; the first half-wave plate and the second half-wave plate respectively adjust the power of the detection light and coupling light, and then input them into a first polarization beam splitter prism and a second polarization beam splitter prism; the first polarization beam splitter prism and the second polarization beam splitter prism respectively align the detection light and coupling light to a first half-wave plate and a second half-wave plate and emit them into a first polarization beam splitter prism and a second polarization beam splitter prism. The vertically polarized light of the coupling light is input into the reflector and the third half-wave plate, and the horizontally polarized light of the detection light and the coupling light is input into the first optical trash can and the second optical trash can; the detection light passing through the reflector is input into the first two-phase prism and then horizontally input into the atomic gas chamber; the polarization angle of the coupling light is adjusted at the third half-wave plate to keep the polarization angle of the coupling light parallel to the polarization angle of the detection light; the coupling light is input into the second two-phase prism to adjust the transmission direction of the coupling light to keep the coupling light and the detection light passing through the atomic gas chamber in the opposite direction and overlapping; the coupling light and the detection light act on the atomic gas chamber where cesium atoms exist at the same time, so that the cesium atoms are converted from the ground state|6S 1 / 2 > Transition to Rydberg state | 28D 5 / 2 >, and the detection light and the coupling light are electromagnetically induced to a transparent effect with the cesium Rydberg atoms in the atomic gas chamber, generating an EIT light peak; when the uniform electric field generated by the voltage-electric field introduction device acts on the cesium Rydberg atoms in the atomic gas chamber, a Stark effect is generated, and the frequency position of the EIT light peak is moved, resulting in a Stark frequency shift, and a Stark frequency shift amount is generated; and after the Stark frequency shift, the coupling light is input from the atomic gas chamber into the first dichroic mirror and enters the third optical trash can, and at the same time, the detection light is input from the atomic gas chamber into the second dichroic mirror through the third collimator and the single-mode optical fiber, generating the detection light after the action of the electric field and the cesium Rydberg atoms and inputting it into the photoelectric converter, converting the transmitted detection light signal into an electrical signal.

7. The Rydberg atom-based power frequency voltage quantum measurement device according to claim 6, characterized in that: The wavelength of the detection light emitted by the single-frequency fiber laser and its frequency stabilization control system module is 852.347nm.

8. The Rydberg atom-based power frequency voltage quantum measurement device according to claim 7, characterized in that: The central wavelength of the coupled light emitted by the single-frequency fiber laser and its frequency stabilization control system module is 512.667nm, and the frequency can be swept within the range of ±1GHz.

9. The Rydberg atom-based power frequency voltage quantum measurement device according to claim 8, characterized in that: The signal processing system is used to receive the electrical signal corresponding to the detection spectrum and perform filtering processing. The specific process of obtaining the voltage to be measured is as follows: First, the electrical signal corresponding to the detection spectrum is received and low-pass filtered to generate a filtered signal; Secondly, the wavelet transform method is used to identify the Stark split peak of the filtered signal, and the frequency position of the Stark split peak is extracted to generate the Stark frequency shift; At the same time, the uniform electric field is calculated based on the Stark frequency shift, that is: Among them, α i represents the polarizability at the i-th energy level, ΔStark represents the Stark frequency shift; Finally, the electric field to be measured is calculated based on the uniform electric field, that is: u(t)=E(t)d.

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