Photon crystal fluorescence-enhanced serf atomic magnetometer detection device and method

Abstract

The present application relates to the field of atomic device technology of atomic magnetometer / atomic gyroscope, and provides a photonic crystal fluorescence enhanced SERF atomic magnetometer detection device and method, aiming at solving the problem that the polarization detection method of the prior art is greatly affected by the changes of light intensity and polarization state. The main scheme includes that fluorescence is used as the excitation light of the photonic crystal fluorescence enhancement film, when the periodic structure of the photonic crystal matches the wavelength of the excitation light, the fluorescence emitted by the fluorescence particles coated on the photonic crystal fluorescence enhancement film is enhanced, the selectivity of the photonic crystal fluorescence enhancement effect to the excitation wavelength is utilized, the corresponding magnetic field condition is uniquely determined by detecting the light wavelength, so that the corresponding relationship between the detection wavelength and the external magnetic field is obtained, and the detection of the magnetic field is realized.

Description

Technical Field

[0001] This invention relates to the field of atomic device technology, specifically atomic magnetometers / atomic gyroscopes. It provides a photonic crystal fluorescence-enhanced SERF atomic magnetometer detection device and method. Background Technology

[0002] An atomic magnetometer is an optical instrument used to detect polarization changes in alkali metal vapors under the influence of an external magnetic field. Among them, the spin-exchange relaxation-free (SERF) atomic magnetometer is a novel type of alkali metal atomic magnetometer operating in the SERF state, whose sensitivity is unaffected by spin exchange relaxation. Although SERF atomic magnetometers possess high sensitivity and accuracy, current polarization detection methods are significantly affected by changes in light intensity and polarization state, limiting further improvements in their sensitivity.

[0003] The method proposed in this invention is a wavelength detection method, which is insensitive to changes in light intensity and polarization state, and can significantly improve the sensitivity and measurement accuracy of the SERF atomic magnetometer. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that existing polarization detection methods are greatly affected by changes in light intensity and polarization state.

[0005] To achieve the above objectives, the present invention employs the following technical means:

[0006] A SERF atomic magnetometer detection device based on photonic crystal fluorescence enhancement includes:

[0007] Three-dimensional coil: Provides an external magnetic field, causing atoms that have entered the excited state to split into hyperfine levels under the influence of the external magnetic field;

[0008] Alkali metal gas chamber: located at the center of the three-dimensional coil, containing alkali metal and inert gas;

[0009] Pump photodiode: Pump light is injected into an alkali metal gas cell, and the atoms in the gas cell enter an excited state under the action of pump light;

[0010] Detection photodiode: Detection light is injected into the alkali metal gas cell. When the wavelength of the detection light matches the hyperfine energy level of the alkali metal atoms under the external magnetic field, a fine transition occurs, thereby causing the alkali metal atoms to produce fluorescence.

[0011] Wavelength meter: Used to detect the wavelength of light.

[0012] Photonic crystal fluorescence enhancement film: The fluorescence of the corresponding wavelength generated by the fine transition is output onto the photonic crystal fluorescence enhancement film;

[0013] Fluorescence is used as the excitation light for photonic crystal fluorescence enhancement films. When the periodic structure of the photonic crystal matches the excitation light wavelength, the fluorescence emitted by the fluorescent particles coated on the photonic crystal fluorescence enhancement film will be enhanced. By utilizing the selectivity of the excitation wavelength to the fluorescence enhancement effect of the photonic crystal, the corresponding magnetic field conditions can be uniquely determined by the detection light wavelength, thereby obtaining the correspondence between the detection wavelength and the external magnetic field and realizing the detection of the magnetic field.

[0014] In the above technical solution, the alkali metal gas chamber is an alkali metal atom gas chamber containing alkali metal potassium, rubidium atoms and inert gas neon atoms.

[0015] In the above technical solution, the four directions of the outer inner ring of the alkali metal gas chamber are the pump light input port, the heating port, the fluorescence output port and the detection light input port, respectively. The outer ring of the alkali metal gas chamber is a three-dimensional coil, which includes an X-direction magnetic field coil, a Y-direction magnetic field coil and a Z-direction magnetic field coil.

[0016] In the above technical solution, the photonic crystal fluorescence enhancement film is an array structure of photonic crystal films with different lattice constants or different fluorescent materials. The number of the photonic crystal fluorescence enhancement film array structure is determined by the specific magnetic field strength range to be measured. The size of each photonic crystal fluorescence enhancement film corresponds to a fine energy level transition. The fluorescence generated by the atomic transition in the alkali metal gas cell is emitted onto the photonic crystal fluorescence enhancement film through the fluorescence output port, selectively enhancing the fluorescence of the fluorescent particles coated on the photonic crystal fluorescence enhancement film.

[0017] A detection method for a SERF atomic magnetometer based on photonic crystal fluorescence enhancement includes the following steps:

[0018] Detection light is injected into the alkali metal gas cell by a detection photodiode, and pump light is injected into the alkali metal gas cell by a pump photodiode. Atoms in the gas cell rise in energy level and enter an excited state under the influence of the pump light. An external magnetic field is provided by a three-dimensional coil, causing the atoms in the excited state to undergo hyperfine level splitting under the influence of the external magnetic field. That is, when the detection light wavelength matches the hyperfine energy level of the atom under the external magnetic field, a fine transition occurs, resulting in fluorescence. The fluorescence of the corresponding wavelength generated by the fine transition is output to the photonic crystal fluorescence enhancement film. The fluorescence serves as the excitation light for the photonic crystal fluorescence enhancement film. When the periodic structure of the photonic crystal matches the excitation light wavelength, the fluorescence emitted by the fluorescent particles coated on the photonic crystal fluorescence enhancement film is enhanced. Utilizing the selectivity of the photonic crystal fluorescence enhancement effect to the excitation wavelength, the corresponding magnetic field condition is uniquely determined by the detection light wavelength, thus obtaining the correspondence between the detection wavelength and the external magnetic field, achieving magnetic field detection.

[0019] In the above technical solution, the alkali metal gas chamber is an alkali metal atom gas chamber containing alkali metal potassium, rubidium atoms and inert gas neon atoms.

[0020] In the above technical solution, the four directions of the outer inner ring of the alkali metal gas chamber are the pump light input port, the heating port, the fluorescence output port and the detection light input port, respectively. The outer ring of the alkali metal gas chamber is a three-dimensional coil, which includes an X-direction magnetic field coil, a Y-direction magnetic field coil and a Z-direction magnetic field coil.

[0021] In the above technical solution, the photonic crystal fluorescence enhancement film is an array structure of photonic crystal films with different lattice constants or different fluorescent materials. The number of the photonic crystal fluorescence enhancement film array structure is determined by the range of the magnetic field strength to be measured. The size of each photonic crystal fluorescence enhancement film corresponds to a fine energy level transition. The fluorescence generated by the atomic transition in the alkali metal gas cell is emitted onto the photonic crystal fluorescence enhancement film through the fluorescence output port, selectively enhancing the fluorescence of the fluorescent particles coated on the photonic crystal fluorescence enhancement film.

[0022] Because the present invention employs the above-mentioned technical means, it has the following beneficial effects:

[0023] The wavelength detection method proposed in this invention is insensitive to changes in light intensity and polarization state, which is beneficial for achieving high-sensitivity and high-precision magnetic field measurements, thereby improving the long-term stability of the SERF atomic magnetometer. Furthermore, the method provided by this invention can also be applied to high-precision detection in SERF atomic gyroscopes. Attached Figure Description

[0024] Figure 1 This is the principle and intent of the present invention.

[0025] Figure 2 A schematic diagram of the Zeeman level splitting of atoms in a gas cell under an applied weak magnetic field, as required by this invention.

[0026] Figure 3 A schematic diagram of the device structure involved in implementing the present invention.

[0027] Figure 4 This is a schematic diagram of the photonic crystal structure used in this invention.

[0028] Figure 5 This is a schematic diagram of a photonic crystal thin film containing fluorescent material, which combines the photonic crystal structure used in this invention with fluorescent material.

[0029] Figure 6 This is a schematic diagram of the photonic crystal fluorescence enhancement film (with two different sizes) used in this invention.

[0030] Figure 7This is a schematic diagram of the photonic crystal fluorescence enhancement film (with four different sizes) used in this invention.

[0031] In the figure: 1-wavelength meter, 2-detection photodiode, 3-pump photodiode, 4-gas cell, 5-photonic crystal fluorescence enhancement film, 6-X-direction coil, 7-Z-direction coil, 8-Y-direction coil, 9- Detailed Implementation

[0032] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0033] This invention provides a SERF atomic magnetometer detection device and method based on photonic crystal fluorescence enhancement, which can detect magnetic fields by utilizing the fluorescence enhancement effect of photonic crystals. Fluorescence generated by atomic transitions in the alkali metal gas cell is projected onto a photonic crystal fluorescence enhancement film through a fluorescence output port. This selectively enhances the fluorescence of the fluorescent particles coated on the photonic crystal fluorescence enhancement film. The size of each photonic crystal fluorescence enhancement film corresponds to a fine-level transition of an alkali metal atom, and this fine-level transition represents the resonance between the detection wavelength and the magnetic field strength. Therefore, the magnetic field can be measured by detecting the light wavelength and the light output of the photonic crystal fluorescence enhancement film.

[0034] Figure 1 This invention relates to the principle and intent of a SERF atomic magnetometer detection method based on photonic crystal fluorescence enhancement. Figure 2 This diagram illustrates the Zeeman level splitting of atoms in a gas cell under an applied weak magnetic field, which is part of the SERF atomic magnetometer detection method based on photonic crystal fluorescence enhancement, as described in this invention. Figure 3 A schematic diagram of the device structure involved in implementing the SERF atomic magnetometer detection method based on photonic crystal fluorescence enhancement of the present invention. Figure 4 This is a schematic diagram of the photonic crystal structure used in this invention. Figure 5 This is a schematic diagram of a photonic crystal thin film containing fluorescent material, which combines the photonic crystal structure used in this invention with fluorescent material. Figure 6 This is a schematic diagram of the photonic crystal fluorescence enhancement film (with two different sizes) used in this invention. Figure 7This is a schematic diagram of the photonic crystal fluorescence enhancement film (with four different sizes) used in this invention. The number of photonic crystal fluorescence enhancement film array structures is determined by the specific magnetic field range to be measured, and the size of each photonic crystal fluorescence enhancement film corresponds to a fine level transition. An atomic gyroscope detection method based on photonic crystal fluorescence enhancement first adjusts a three-dimensional coil. Under known magnetic field conditions, the wavelength of the detection light is changed within a certain range until the photonic crystal fluorescence enhancement film emits the strongest fluorescence. At this point, the frequency of the detection light matches the hyperfine level transition, and the corresponding wavelength and magnetic field strength are recorded to obtain a correspondence. Similarly, by changing the known magnetic field strength, the wavelength that causes the photonic crystal fluorescence enhancement film to emit the strongest fluorescence under each magnetic field strength is recorded, thus obtaining the correspondence between the detection light wavelength and the magnetic field conditions. When the magnetic field conditions are unknown, the wavelength of the detection light is changed to make the photonic crystal fluorescence enhancement film emit the strongest fluorescence. The value of the magnetic field is determined based on the wavelength corresponding to the strongest fluorescence state, thus achieving magnetic field detection.

[0035] The method provided by this invention can also be applied to high-precision detection of SERF atomic gyroscopes. Specifically, when the atomic gyroscope undergoes an angular change, the detection light and the precession direction of the neon atoms in the gas cell form an angle, effectively equivalent to an external magnetic field. When the rotation angle is known, the wavelength of the detection light is varied within a certain range until the photonic crystal fluorescence enhancement film emits its strongest fluorescence. The corresponding wavelength and rotation angle are recorded to obtain a set of correspondences. Similarly, by changing the known rotation angle, the wavelength positions corresponding to the strongest fluorescence emitted by the photonic crystal fluorescence enhancement film at different rotation angles are recorded, thereby obtaining the correspondence between the detection light wavelength and the rotation angle. When the rotation angle is unknown, the wavelength of the detection light is changed until the photonic crystal fluorescence enhancement film emits its strongest fluorescence. The rotation angle is determined based on the wavelength corresponding to the strongest fluorescence state, thus achieving the detection of the rotation angle.

[0036] Contents not described in detail in this specification are prior art known to those skilled in the art. It is hereby indicated that the above description is intended to help those skilled in the art understand this invention, but does not limit the scope of protection of this invention. Any equivalent substitutions, modifications, improvements, and / or simplifications of the above descriptions that do not depart from the essential content of this invention fall within the scope of protection of this invention.

Claims

1. A SERF atomic magnetometer detection device based on photonic crystal fluorescence enhancement, characterized in that, include: Three-dimensional coil: Provides an external magnetic field, causing atoms that have entered the excited state to split into hyperfine levels under the influence of the external magnetic field; Alkali metal gas chamber: located at the center of the three-dimensional coil, containing alkali metal and inert gas; Pump photodiode: Pump light is injected into an alkali metal gas cell, and the atoms in the gas cell enter an excited state under the action of pump light; Detection photodiode: Detection light is injected into the alkali metal gas cell. When the wavelength of the detection light matches the hyperfine energy level of the alkali metal atoms under the external magnetic field, a fine transition occurs, thereby causing the alkali metal atoms to produce fluorescence. Wavelength meter: Used to detect the wavelength of light. Photonic crystal fluorescence enhancement film: The fluorescence of the corresponding wavelength generated by the fine transition is output onto the photonic crystal fluorescence enhancement film; Fluorescence is used as the excitation light for photonic crystal fluorescence enhancement films. When the periodic structure of the photonic crystal matches the excitation light wavelength, the fluorescence emitted by the fluorescent particles coated on the photonic crystal fluorescence enhancement film will be enhanced. By utilizing the selectivity of the excitation wavelength to the fluorescence enhancement effect of the photonic crystal, the corresponding magnetic field conditions can be uniquely determined by the detection light wavelength, thereby obtaining the correspondence between the detection wavelength and the external magnetic field and realizing the detection of the magnetic field.

2. The SERF atomic magnetometer detection device based on photonic crystal fluorescence enhancement according to claim 1, characterized in that, An alkali metal chamber is a chamber containing alkali metal atoms such as potassium and rubidium, and inert gas neon.

3. The SERF atomic magnetometer detection device based on photonic crystal fluorescence enhancement according to claim 1, characterized in that, The inner ring of the alkali metal gas chamber has a pump light input port, a heating port, a fluorescence output port, and a detection light input port in four directions. The outer ring of the alkali metal gas chamber is a three-dimensional coil, which includes an X-direction magnetic field coil, a Y-direction magnetic field coil, and a Z-direction magnetic field coil.

4. The SERF atomic magnetometer detection device based on photonic crystal fluorescence enhancement according to claim 1, characterized in that, The photonic crystal fluorescence enhancement film is an array structure of photonic crystal films with different lattice constants or different fluorescent materials. The number of the photonic crystal fluorescence enhancement film array structures is determined by the specific magnetic field strength range to be measured. The size of each photonic crystal fluorescence enhancement film corresponds to a fine energy level transition. The fluorescence generated by the atomic transition in the alkali metal gas cell is emitted onto the photonic crystal fluorescence enhancement film through the fluorescence output port, selectively enhancing the fluorescence of the fluorescent particles coated on the photonic crystal fluorescence enhancement film.

5. A detection method for a SERF atomic magnetometer based on photonic crystal fluorescence enhancement, characterized in that: Includes the following steps: Detection light is injected into the alkali metal gas cell by a detection photodiode, and pump light is injected into the alkali metal gas cell by a pump photodiode. Atoms in the gas cell rise in energy level and enter an excited state under the influence of the pump light. An external magnetic field is provided by a three-dimensional coil, causing the atoms in the excited state to undergo hyperfine level splitting under the influence of the external magnetic field. That is, when the detection light wavelength matches the hyperfine energy level of the atom under the external magnetic field, a fine transition occurs, resulting in fluorescence. The fluorescence of the corresponding wavelength generated by the fine transition is output to the photonic crystal fluorescence enhancement film. The fluorescence serves as the excitation light for the photonic crystal fluorescence enhancement film. When the periodic structure of the photonic crystal matches the excitation light wavelength, the fluorescence emitted by the fluorescent particles coated on the photonic crystal fluorescence enhancement film is enhanced. Utilizing the selectivity of the photonic crystal fluorescence enhancement effect to the excitation wavelength, the corresponding magnetic field condition is uniquely determined by the detection light wavelength, thus obtaining the correspondence between the detection wavelength and the external magnetic field, achieving magnetic field detection.

6. The detection method of a SERF atomic magnetometer based on photonic crystal fluorescence enhancement according to claim 5, characterized in that: An alkali metal chamber is a chamber containing alkali metal atoms such as potassium and rubidium, and inert gas neon.

7. The detection method of a SERF atomic magnetometer based on photonic crystal fluorescence enhancement according to claim 5, characterized in that, The inner ring of the alkali metal gas chamber has a pump light input port, a heating port, a fluorescence output port, and a detection light input port in four directions. The outer ring of the alkali metal gas chamber is a three-dimensional coil, which includes an X-direction magnetic field coil, a Y-direction magnetic field coil, and a Z-direction magnetic field coil.

8. The detection method of a SERF atomic magnetometer based on photonic crystal fluorescence enhancement according to claim 5, characterized in that, The photonic crystal fluorescence enhancement film is an array structure of photonic crystal films with different lattice constants or different fluorescent materials. The number of the photonic crystal fluorescence enhancement film array structures is determined by the range of the magnetic field strength to be measured. The size of each photonic crystal fluorescence enhancement film corresponds to a fine energy level transition. The fluorescence generated by the atomic transition in the alkali metal gas cell is emitted onto the photonic crystal fluorescence enhancement film through the fluorescence output port, selectively enhancing the fluorescence of the fluorescent particles coated on the photonic crystal fluorescence enhancement film.

Images