CN114217249B - Non-blind-area magnetic field measuring device and measuring method based on laser polarization modulation - Google Patents
Non-blind-area magnetic field measuring device and measuring method based on laser polarization modulation Download PDFInfo
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- CN114217249B CN114217249B CN202111543400.3A CN202111543400A CN114217249B CN 114217249 B CN114217249 B CN 114217249B CN 202111543400 A CN202111543400 A CN 202111543400A CN 114217249 B CN114217249 B CN 114217249B
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- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
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- G01R33/02—Measuring direction or magnitude of magnetic fields or magnetic flux
- G01R33/032—Measuring direction or magnitude of magnetic fields or magnetic flux using magneto-optic devices, e.g. Faraday or Cotton-Mouton effect
Abstract
The invention provides a non-blind area magnetic field measuring device and a measuring method based on laser polarization modulation, wherein the non-blind area magnetic field measuring device comprises a light path module, an atomic gas chamber, a temperature control module, a magnetic field control module and a signal analysis control module; filling alkali metal atoms in the atom gas chamber as a working substance; the optical path module is used for pumping and detecting alkali metal atoms in the atom gas chamber; the temperature control module is used for stabilizing the temperature of the atomic gas chamber within the range of +/-1 ℃ of the preset temperature; the magnetic field control module is used for generating an alternating excitation magnetic field required by the atomic gas chamber; and the signal analysis control module is used for calculating to obtain the magnetic field intensity and the azimuth information to be measured. The method effectively eliminates the vector magnetic field measurement blind area corresponding to tensor polarization single distribution.
Description
Technical Field
The invention relates to the technical field of magnetic field measurement, in particular to a non-blind-area magnetic field measurement device and method based on laser polarization modulation.
Background
The parameters characterizing the magnetic field are mainly two, namely the magnetic field intensity and the magnetic field direction. Magnetometers are a generic term for devices that implement magnetic field measurements. Magnetometers can be classified into scalar magnetometers (or total field magnetometers) and vector magnetometers, according to the type of measurement data. Scalar magnetometer can only obtain the intensity information of the magnetic field to be measured, and vector magnetometer can obtain the intensity and azimuth information of the magnetic field to be measured. Taking target detection application as an example, the scalar magnetometer can obtain the distance from the target to be detected to the measurement point, and the vector magnetometer can obtain the azimuth information of the target to be detected. Therefore, the vector magnetometer can have more dimensionality information and has wider application prospect.
The atomic magnetometer can realize high-sensitivity magnetic field detection, has the outstanding advantages of miniaturization and low power consumption, and is the main development direction of the future integrated high-sensitivity magnetic detection technology. Most atomic magnetometers are based on polarization of the atomic spin vector produced by circular polarized laser pumping, and are essentially scalar magnetometers. By means of compensation, modulation and other methods, the atomic magnetometer can also be used for obtaining orientation information such as the direction and the spatial distribution of the magnetic field. Most of the indirect measurement methods utilize a three-dimensional magnetic field coil to establish a spatial direction reference, and the spatial direction of a magnetic field to be measured is reversely deduced by respectively compensating the amplitudes of the three directional magnetic fields to be zero. Therefore, high requirements are put on the space orthogonality of the magnetic field coils, the inter-axis isolation and the magnetic field current compensation precision, and the advantage of high sensitivity of the atomic magnetometer cannot be achieved.
The linearly polarized laser light can produce a symmetric distribution of tensor polarization in the light polarization direction by the electron self-rotation of the alkali metal atom. Magnetic field vector information can be directly measured by utilizing tensor polarization of atoms, but when an included angle between a magnetic field to be measured and linearly polarized light is a specific value, a measuring blind area exists, and the difference of response sensitivity to magnetic fields with different directions is large.
The presence of measurement blind areas has become the primary elbow that limits further development applications of vector atomic magnetometers.
Disclosure of Invention
The invention aims to provide a non-blind-zone magnetic field measuring device and a measuring method based on laser polarization modulation. The specific technical scheme is as follows:
a non-blind area magnetic field measuring device based on laser polarization modulation comprises a light path module, an atomic gas chamber, a temperature control module, a magnetic field control module and a signal analysis control module;
filling alkali metal atoms in the atom gas chamber as a working substance;
the optical path module is used for pumping and detecting alkali metal atoms in the atomic gas chamber and comprises a laser controller, a laser, a first half wave plate, a polarization spectroscope, a first photoelectric detector, a second half wave plate, a liquid crystal polarization rotator driver, a first reflector, a beam expanding system, a focusing system, a second reflector and a second photoelectric detector; the laser is used for emitting linear polarization laser to the atomic gas chamber; the laser band of the linearly polarized laser is positioned in the D2 transition frequency band of the selected alkali metal atom in the atom gas chamber; the laser controller is used for realizing selection and stabilization of the laser frequency and power of linearly polarized laser; the polarization spectroscope is arranged on a light path of the linearly polarized laser and is used for dividing the linearly polarized laser into a reference beam and a main beam; the first photoelectric detector is arranged on the light path of the reference beam and used for feeding back a laser control signal to the laser controller; the first one-half wave plate is arranged between the laser and the polarization spectroscope and used for adjusting the power of the reference beam and the power of the main beam; the second half-wave plate, the liquid crystal polarization rotator, the first reflector, the beam expanding system, the focusing system, the second reflector and the second photoelectric detector are sequentially arranged on a light path of the main light beam, wherein the beam expanding system and the focusing system are respectively arranged on two sides of the atomic gas chamber; the liquid crystal polarization rotator driver is arranged between the signal analysis control module and the liquid crystal polarization rotator; the second half wave plate is used for adjusting the direction of the main laser polarization axis of the main beam before entering the liquid crystal polarization rotator; the liquid crystal polarization rotator is used for realizing dynamic adjustment of the main beam laser polarization direction under the action of a liquid crystal polarization rotator driver; the beam expanding system is used for expanding the spot size of the main beam laser to cover the atomic gas chamber; the focusing system is used for converging the main beam laser which penetrates through the atomic gas chamber; the reflection directions of the first reflector and the second reflector can be independently adjusted, and the first reflector and the second reflector are used for adjusting the traveling direction of the main beam laser; the second photoelectric detector is used for detecting the optical power change of the main beam laser which penetrates through the atomic gas chamber;
the temperature control module comprises a temperature measuring resistor, a thermal drying oven, a radio frequency power amplifier driver and a temperature control processor; the temperature measuring resistor is connected with the temperature control processor; the temperature control processor and the thermal oven are respectively connected with the radio frequency power amplifier driver; the temperature measuring resistor is used for measuring the temperature around the atomic gas chamber, the thermal oven is driven by the radio frequency power amplifier driver to heat the atomic gas chamber, and the temperature control processor adjusts the output current of the radio frequency power amplifier driver in real time according to the measured temperature returned by the temperature measuring resistor;
the magnetic field control module comprises a magnetic field coil arranged around the atom gas chamber and a magnetic field driving source for controlling the magnetic field coil to generate magnetic field intensity, and an alternating excitation magnetic field is generated by the magnetic field coil and an external environment magnetic field of alkali metal atoms is shielded at the same time; the alternating frequency of the alternating excitation magnetic field is equal to the Larmor precession frequency of alkali metal atom spin under the action of a detection magnetic field;
the signal analysis control module comprises a digital-to-analog/analog-to-digital conversion circuit and a data processing terminal, and the data processing terminal is connected with the digital-to-analog/analog-to-digital conversion circuit; the digital-to-analog/analog conversion circuit is respectively connected with the second photoelectric detector, the liquid crystal polarization rotator driver and the magnetic field driving source, and the data processing terminal analyzes the signal from the second photoelectric detector to calculate the magnetic field intensity data sensed by the spin of the alkali metal atoms, and sends a liquid crystal polarization signal to the liquid crystal polarization rotator driver and a magnetic field control signal to the magnetic field driving source.
Preferably, the magnification of the beam expanding system and the magnification of the focusing system can be adjusted independently.
Preferably, the temperature measuring resistor is connected with the temperature control processor through a data transmission line; the temperature control processor and the hot oven are respectively connected with the radio frequency power amplifier driver through data transmission lines.
Preferably, the digital-to-analog/analog-to-digital conversion circuit comprises an analog-to-digital conversion circuit and a digital-to-analog conversion circuit, and an input end of the analog-to-digital conversion circuit is connected with an output end of the second photodetector through a data transmission line; the output end of the digital-to-analog conversion circuit is respectively connected with the liquid crystal polarization rotator driver and the magnetic field driving source through data transmission lines; the output end of the analog-to-digital conversion circuit and the input end of the digital-to-analog conversion circuit are respectively connected with a data processing terminal through data transmission lines.
Preferably, the atomic gas chamber is a sealed light-transmitting glass gas chamber; the magnetic field coil is a three-dimensional Helmholtz magnetic field coil; the temperature control processor is a single chip microcomputer.
A measuring method of the non-blind-zone magnetic field measuring device based on laser polarization modulation comprises the following steps:
s1, assembling the non-blind-area magnetic field measuring device based on laser polarization modulation according to a laser passing sequence and a connection relation between components;
s2, the laser emits ray polarized laser under the drive of a laser controller; the linear polarization laser is divided into a reference beam and a main beam after passing through a polarization beam splitter; the first photoelectric detector is arranged on the light path of the reference beam and used for feeding back a laser control signal to the laser controller, so that the laser controller realizes the selection and stabilization of laser frequency and power; the second half wave plate is used for adjusting the direction of the main laser polarization axis of the main beam before entering the liquid crystal polarization rotator, so that the direction of the main laser polarization axis falls in the central area of the control range of the liquid crystal polarization rotator; the main beam laser covers the atomic gas chamber after passing through the beam expanding system; the size of the light spot of the transmitted laser passing through the focusing system is smaller than that of the photosensitive surface of the second photoelectric detector, the transmitted laser passes through the second reflector and is received by the second photoelectric detector, and the optical signal is converted into an electric signal and is transmitted to the data processing terminal through the digital-to-analog/analog-to-digital conversion circuit;
s3, the data processing terminal sends a magnetic field control signal to a magnetic field driving source; the magnetic field driving source generates an alternating excitation magnetic field required by the atomic gas chamber according to the magnetic field control signal;
s4, the temperature control processor adjusts the output current of the radio frequency power amplifier driver in real time according to the measured temperature returned by the temperature measuring resistor, so that the temperature of the atomic gas chamber is stabilized within the range of +/-1 ℃ of the preset temperature;
s5, the data processing terminal sends a liquid crystal polarization signal to a liquid crystal polarization rotator driver, and the main beam laser polarization direction passing through the liquid crystal polarization rotator is rotated by regulating and controlling the output control voltage of the liquid crystal polarization rotator driver so as to realize dynamic adjustment of the main beam laser polarization direction;
and S6, resolving by the data processing terminal according to the electric signal input by the second photoelectric detector and the liquid crystal polarization signal sent to the liquid crystal polarization rotator driver to obtain the magnetic field intensity and the azimuth information to be measured.
Preferably, the preset temperature in step S4 is 40-100 ℃.
Preferably, the liquid crystal polarization signal in step S5 is a square wave signal for periodically adjusting the liquid crystal polarization rotator; when the square wave is at a low level, the square wave is dynamically adjusted, and the polarization direction of the transmission laser does not deflect; when the square wave is at a high level, the transmitted laser polarization direction produces a 45 ° rotation.
Preferably, the low level is 0v; the high level is 2.0-2.5V.
The technical scheme of the invention at least has the following beneficial effects:
(1) According to the non-blind-zone magnetic field measuring device based on laser polarization modulation, the liquid crystal polarization signal is sent to the liquid crystal polarization rotator driver through the data processing terminal, the polarization direction of linear polarization laser is dynamically adjusted for the liquid crystal polarization rotator, so that tensor polarization distribution of atomic spin in an atomic gas chamber is periodically changed, and a vector magnetic field measuring blind zone corresponding to tensor polarization single distribution is effectively eliminated.
(2) The invention realizes equivalent interaction of the multi-beam linearly polarized light and the atomic gas chamber in a single-beam linearly polarized light polarization modulation mode, has simple structure and compact device, realizes effective non-blind-area magnetic field measurement on the premise of not adding the number of gauge outfit measuring units, and saves the measurement cost.
(3) The reflection directions of the first reflector and the second reflector can be independently adjusted, and the amplification factors of the beam expanding system and the focusing system can be adjusted, so that the non-blind-area magnetic field measuring device constructed by the invention is suitable for various atomic gas chambers with different shapes and sizes, and the light beam advancing direction and the light spot size can be changed according to the actual application requirements.
In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be described in further detail below with reference to the drawings.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 is a schematic structural diagram of a non-blind-area magnetic field measurement apparatus based on laser polarization modulation in embodiment 1 of the present invention;
in fig. 1:
101. the laser polarization analyzer comprises a laser controller, 102, a laser, 103, a first half wave plate, 104, a polarization beam splitter, 105, a first photoelectric detector, 106, a second half wave plate, 107, a liquid crystal polarization rotator, 108, a liquid crystal polarization rotator driver, 109, a first reflector, 110, a beam expanding system, 111, a focusing system, 112, a second reflector, 113 and a second photoelectric detector; 201. an atomic gas cell; 301. a temperature measuring resistor 302, a hot oven 303, a radio frequency power amplifier driver 304 and a temperature control processor; 401. a magnetic field drive source 402 and a magnetic field coil; 501. digital-to-analog/analog-to-digital conversion circuit 502 and data processing terminal.
FIG. 2 is a theoretical analysis model of a non-blind-zone magnetic field measuring device based on laser polarization modulation in embodiment 1 of the present invention;
in fig. 2:
x, y, z represent the x, y, z axes of an orthogonal coordinate system, B 0 Representing the amplitude of the magnetic field to be measured, B rf The amplitude of the excitation magnetic field is shown, k is the laser advancing direction, epsilon is the laser polarization direction, alpha is the included angle between the laser polarization direction and the direction of the magnetic field to be measured, and psi is the included angle between the excitation magnetic field and the xz plane.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.
Example 1:
referring to fig. 1, a non-blind area magnetic field measuring device based on laser polarization modulation comprises a light path module, an atomic gas chamber 201, a temperature control module, a magnetic field control module and a signal analysis control module;
the atomic gas chamber 201 (which is a cubic gas chamber) is filled with alkali metal atoms (specifically cesium) as working substances; the inside of the atomic gas chamber 201 is also filled with a buffer gas (specifically, nitrogen) and a quenching gas (specifically, helium).
The optical path module is used for pumping and detecting alkali metal atoms in the atom gas chamber 201, and comprises a laser controller 101, a laser 102, a first half wave plate 103, a polarization beam splitter 104, a first photoelectric detector 105, a second half wave plate 106, a liquid crystal polarization rotator 107, a liquid crystal polarization rotator driver 108, a first reflector 109, a beam expanding system 110, a focusing system 111, a second reflector 112 and a second photoelectric detector 113; the laser 102 is used for emitting linearly polarized laser to the atomic gas cell 201; the laser band of the linearly polarized laser is positioned in the D2 transition frequency band of the selected alkali metal atom in the atom gas chamber 201; the laser controller 101 is used for selecting and stabilizing the laser frequency and power of linearly polarized laser; the polarization beam splitter 104 is arranged on the light path of the linearly polarized laser and is used for splitting the linearly polarized laser into a reference beam and a main beam; the first photodetector 105 is disposed on the optical path of the reference beam and is configured to feed back a laser control signal to the laser controller 101; the first one-half wave plate 103 is arranged between the laser 102 and the polarization beam splitter 104 and is used for adjusting the power of the reference beam and the main beam; the second half wave plate 106, the liquid crystal polarization rotator 107, the first reflector 109, the beam expanding system 110, the focusing system 111, the second reflector 112 and the second photodetector 113 are sequentially arranged on an optical path of the main beam, wherein the beam expanding system 110 and the focusing system 111 are respectively arranged on two sides of the atomic gas chamber 201; the liquid crystal polarization rotator driver 108 is arranged between the signal analysis control module and the liquid crystal polarization rotator 107; the second half wave plate 106 is used for adjusting the direction of the main polarization axis of the main laser beam before entering the liquid crystal polarization rotator 107; the liquid crystal polarization rotator 107 is used for realizing dynamic adjustment of the main beam laser polarization direction under the action of the liquid crystal polarization rotator driver 108; the beam expanding system 110 is used for expanding the spot size of the main beam laser to cover the atomic gas chamber 201; the focusing system 111 is used for converging the main beam laser transmitted through the atomic gas cell 201; the reflection directions of the first mirror 109 and the second mirror 112 can be adjusted independently, and both are used for adjusting the traveling direction of the main beam laser; the second photodetector 113 is configured to detect a change in optical power of the main beam laser transmitted through the atomic gas cell 201;
the temperature control module comprises a temperature measuring resistor 301, a hot oven 302, a radio frequency power amplifier driver 303 and a temperature control processor 304; the temperature measuring resistor 301 is connected with the temperature control processor 304; the temperature control processor 304 and the hot oven 302 are respectively connected with a radio frequency power amplifier driver 303; the temperature measuring resistor 301 (when the side length of the atomic gas chamber 201 is less than or equal to 10mm, the temperature measuring resistor 301 is arranged close to the atomic gas chamber 201, does not contact with the outer wall of the atomic gas chamber 201, and has a distance of less than or equal to 5mm; when the side length of the atomic gas chamber 201 is greater than 10mm, the temperature measuring resistor 301 is arranged on the outer wall of the atomic gas chamber 201) is used for measuring the temperature around the atomic gas chamber 201, the heat oven 302 is driven by the radio frequency power amplifier driver 303 to heat the atomic gas chamber 201, and the temperature control processor 304 adjusts the output current of the radio frequency power amplifier driver 303 in real time according to the measured temperature returned by the temperature measuring resistor 301;
the magnetic field control module comprises a magnetic field coil 402 arranged around an atom gas chamber and a magnetic field driving source 401 for controlling the magnetic field coil to generate magnetic field intensity, and an external environment magnetic field for generating an alternating excitation magnetic field and shielding alkali metal atoms simultaneously is generated through the magnetic field coil 402; the alternating excitation magnetic field is the alternating excitation magnetic field required by the magnetic resonance of the alkali metal atoms, and the alternating frequency of the alternating excitation magnetic field is equal to the Larmor precession frequency of the alkali metal atom spin under the action of the detection magnetic field;
the signal analysis control module comprises a digital-to-analog/analog-to-digital conversion circuit 501 and a data processing terminal 502, and the data processing terminal 502 is connected with the digital-to-analog/analog-to-digital conversion circuit 501; the digital-to-analog/analog conversion circuit 501 is connected to the second photodetector 113, the liquid crystal polarization rotator driver 108, and the magnetic field driving source 401, and analyzes the signal from the second photodetector 113 through the data processing terminal 502 to calculate the magnetic field strength data sensed by the spin of the alkali metal atom, and sends a liquid crystal polarization signal to the liquid crystal polarization rotator driver 108 and a magnetic field control signal to the magnetic field driving source 401.
The amplification factors of the beam expanding system 110 and the focusing system 111 can be independently adjusted, the size of the light spot of the main beam laser passing through the beam expanding system 110 is adjusted to cover the atomic air chamber 201, and the size of the light spot of the main beam laser passing through the focusing system 111 is adjusted to be smaller than the size of the photosensitive surface of the second photoelectric detector 113.
The temperature measuring resistor 301 is connected with the temperature control processor 304 through a data transmission line; the temperature control processor 304 and the thermal oven 302 are respectively connected with the radio frequency power amplifier driver 303 through data transmission lines.
The digital-to-analog/analog-to-digital conversion circuit 501 comprises an analog-to-digital conversion circuit and a digital-to-analog conversion circuit, and an input end of the analog-to-digital conversion circuit is connected with an output end of the second photodetector 113 through a data transmission line; the output end of the digital-to-analog conversion circuit is respectively connected with the liquid crystal polarization rotator driver 108 and the magnetic field driving source 401 through data transmission lines; the output end of the analog-to-digital conversion circuit and the input end of the digital-to-analog conversion circuit are respectively connected with the data processing terminal 502 through data transmission lines.
The atomic gas chamber 201 is a sealed light-transmitting glass gas chamber; the magnetic field coils 402 are three-dimensional Helmholtz magnetic field coils; the temperature control processor 304 is a single chip microcomputer.
The working principle of the non-blind-zone magnetic field measuring device based on laser polarization modulation is as follows:
after the alkali metal atoms in the atomic gas cell 201 are polarized by the linearly polarized laser, tensor polarization is generated by the spin of the alkali metal atoms. When magnetic resonance occurs, the laser light amplitude variation frequency output by the second photodetector 113 corresponds to the larmor precession frequency ω = γ B 0 . Wherein γ represents a gyromagnetic ratio of an alkali metal atom, and is a constant; b 0 Representing the magnitude of the magnetic field to be measured. The laser light amplitude change phase information output by the second photodetector 113 includes orientation information of the magnetic field to be measured:
wherein alpha represents an included angle between the laser polarization direction and the direction of the magnetic field to be measured; psi represents the angle between the excitation magnetic field and the xz plane, which is perpendicular to the laser travel direction k;
a phase representing a first harmonic of the output signal of the second photodetector 113;
is shown asThe two photodetectors 113 output the phase of the second harmonic of the signal. According to the expression (1) and the expression (2), the magnetic field measurement blind zone is related to the polarization direction of the laser. The invention realizes the non-blind area magnetic field measurement by periodically rotating the polarization direction of the laser.
A measuring method of the non-blind-zone magnetic field measuring device based on laser polarization modulation comprises the following steps:
s1, assembling the non-blind-area magnetic field measuring device based on laser polarization modulation according to a laser passing sequence and a connection relation between components;
s2, the laser 102 emits ray polarized laser under the driving of the laser controller 101; the linearly polarized laser light is divided into a reference beam and a main beam after passing through the polarization beam splitter 104; the first photodetector 105 is disposed on an optical path of the reference beam, and is configured to feed back a laser control signal to the laser controller 101, so that the laser controller 101 selects and stabilizes laser frequency and power; the second half-wave plate 106 is used for adjusting the direction of the main polarization axis of the main laser beam before entering the liquid crystal polarization rotator 107, so that the direction of the main polarization axis of the laser beam falls in the central area of the control range of the liquid crystal polarization rotator 107; the main beam laser covers the atom air chamber 201 after passing through the beam expanding system 110; the size of the light spot of the transmitted laser passing through the focusing system 111 is smaller than the size of the photosensitive surface of the second photoelectric detector, the transmitted laser passes through the second reflecting mirror 112 and is received by the second photoelectric detector 113, the optical signal is converted into an electric signal, and the electric signal is transmitted to the data processing terminal 502 through the digital-to-analog/analog-to-digital conversion circuit 501;
step S3, the data processing terminal 502 sends a magnetic field control signal to the magnetic field driving source 401; the magnetic field driving source 401 generates an alternating excitation magnetic field required by the atomic gas cell 201 according to the magnetic field control signal;
s4, the temperature control processor 304 adjusts the output current of the radio frequency power amplifier driver 303 in real time according to the measured temperature returned by the temperature measuring resistor 301, so that the temperature of the atomic gas chamber 201 is stabilized within the range of +/-1 ℃ of the preset temperature;
step S5, the data processing terminal 502 sends out a liquid crystal polarization signal to the liquid crystal polarization rotator driver 108, and the main beam laser polarization direction passing through the liquid crystal polarization rotator 107 is rotated by regulating and controlling the control voltage output by the liquid crystal polarization rotator driver 108, so as to realize the dynamic adjustment of the main beam laser polarization direction;
step S6, the data processing terminal 502 obtains the magnetic field strength to be measured and the azimuth information by resolving according to the electrical signal input by the second photodetector 113 and the liquid crystal polarization signal sent to the liquid crystal polarization rotator driver 108.
The preset temperature in step S4 is 40-100 ℃.
The liquid crystal polarization signal in step S5 is a square wave signal for periodically adjusting the liquid crystal polarization rotator 107; when the square wave is at a low level, the square wave is dynamically adjusted, and the polarization direction of the transmission laser does not deflect; when the square wave is at a high level, a 45 ° rotation of the transmitted laser polarization direction occurs.
The low level is 0v; the high level is 2.0-2.5V.
The non-blind-zone magnetic field measuring device based on laser polarization modulation sends a liquid crystal polarization signal to the liquid crystal polarization rotator driver 108 through the data processing terminal 502, and realizes the dynamic adjustment of the polarization direction of linear polarization laser to the liquid crystal polarization rotator 107, so that the tensor polarization distribution of atomic spin in the atomic gas chamber 201 is periodically changed, and the vector magnetic field measuring blind zone corresponding to the tensor polarization single distribution is effectively eliminated. The device has simple structure and easy realization, and can give full play to the outstanding advantages of high sensitivity and vector measurement of the atomic magnetometer. The invention has simple structure, convenient operation, strong portability and practicability, and can be used for atomic gas chambers of different types.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A non-blind area magnetic field measuring device based on laser polarization modulation is characterized by comprising a light path module, an atomic gas chamber (201), a temperature control module, a magnetic field control module and a signal analysis control module;
alkali metal atoms are filled in the atomic gas chamber (201) to serve as working substances;
the light path module is used for pumping and detecting alkali metal atoms in an atom gas chamber (201), and comprises a laser controller (101), a laser (102), a first half wave plate (103), a polarization beam splitter (104), a first photoelectric detector (105), a second half wave plate (106), a liquid crystal polarization rotator (107), a liquid crystal polarization rotator driver (108), a first reflector (109), a beam expanding system (110), a focusing system (111), a second reflector (112) and a second photoelectric detector (113); the laser (102) is used for emitting linearly polarized laser to the atomic gas chamber (201); the laser band of the linear polarization laser is positioned in the D2 transition frequency band of the selected alkali metal atom in the atom gas chamber (201); the laser controller (101) is used for realizing selection and stabilization of laser frequency and power of linearly polarized laser; the polarization beam splitter (104) is arranged on the light path of the linearly polarized laser and is used for splitting the linearly polarized laser into a reference beam and a main beam; the first photoelectric detector (105) is arranged on the optical path of the reference beam and used for feeding back a laser control signal to the laser controller (101); the first half wave plate (103) is arranged between the laser (102) and the polarization beam splitter (104) and is used for adjusting the power of the reference beam and the main beam; the second half wave plate (106), the liquid crystal polarization rotator (107), the first reflector (109), the beam expanding system (110), the focusing system (111), the second reflector (112) and the second photoelectric detector (113) are sequentially arranged on an optical path of the main light beam, wherein the beam expanding system (110) and the focusing system (111) are respectively arranged on two sides of the atomic gas chamber (201); the liquid crystal polarization rotator driver (108) is arranged between the signal analysis control module and the liquid crystal polarization rotator (107); the second half wave plate (106) is used for adjusting the direction of the main polarization axis of the main laser beam before entering the liquid crystal polarization rotator (107); the liquid crystal polarization rotator (107) is used for realizing dynamic adjustment of the main beam laser polarization direction under the action of a liquid crystal polarization rotator driver (108); the beam expanding system (110) is used for expanding the spot size of the main beam laser to cover the atomic gas chamber (201); the focusing system (111) is used for converging the main beam laser which is transmitted through the atomic gas chamber (201); the reflection directions of the first reflector (109) and the second reflector (112) can be adjusted independently, and the first reflector and the second reflector are used for adjusting the traveling direction of the main beam laser; the second photoelectric detector (113) is used for detecting the optical power change of the main beam laser transmitted through the atomic gas cell (201);
the temperature control module comprises a temperature measuring resistor (301), a hot oven (302), a radio frequency power amplifier driver (303) and a temperature control processor (304); the temperature measuring resistor (301) is connected with the temperature control processor (304); the temperature control processor (304) and the thermal oven (302) are respectively connected with the radio frequency power amplifier driver (303); the temperature measuring resistor (301) is used for measuring the temperature around the atomic gas chamber (201), the thermal oven (302) is driven by the radio frequency power amplifier driver (303) to heat the atomic gas chamber (201), and the temperature control processor (304) adjusts the output current of the radio frequency power amplifier driver (303) in real time according to the measured temperature returned by the temperature measuring resistor (301);
the magnetic field control module comprises a magnetic field coil (402) arranged around the atomic gas chamber and a magnetic field driving source (401) used for controlling the magnetic field coil to generate magnetic field intensity, and an external environment magnetic field which generates an alternating excitation magnetic field and shields alkali metal atoms simultaneously is generated through the magnetic field coil (402); the alternating frequency of the alternating excitation magnetic field is equal to the Larmor precession frequency of alkali metal atom spin under the action of a detection magnetic field;
the signal analysis control module comprises a digital-to-analog/analog-to-digital conversion circuit (501) and a data processing terminal (502), and the data processing terminal (502) is connected with the digital-to-analog/analog-to-digital conversion circuit (501); the digital-to-analog/analog conversion circuit (501) is respectively connected with the second photoelectric detector (113), the liquid crystal polarization rotator driver (108) and the magnetic field driving source (401), and analyzes signals from the second photoelectric detector (113) through the data processing terminal (502) to calculate magnetic field intensity data sensed by the spin of alkali metal atoms, sends liquid crystal polarization signals to the liquid crystal polarization rotator driver (108) and sends magnetic field control signals to the magnetic field driving source (401);
the digital-to-analog/analog-to-digital conversion circuit (501) comprises an analog-to-digital conversion circuit and a digital-to-analog conversion circuit, and the input end of the analog-to-digital conversion circuit is connected with the output end of the second photoelectric detector (113) through a data transmission line; the output end of the digital-to-analog conversion circuit is respectively connected with the liquid crystal polarization rotator driver (108) and the magnetic field driving source (401) through data transmission lines; the output end of the analog-to-digital conversion circuit and the input end of the digital-to-analog conversion circuit are respectively connected with a data processing terminal (502) through data transmission lines.
2. The laser polarization modulation-based blind-area-free magnetic field measurement device is characterized in that the amplification factors of the beam expanding system (110) and the focusing system (111) can be adjusted independently.
3. The laser polarization modulation-based blind-area-free magnetic field measurement device is characterized in that the temperature measuring resistor (301) is connected with the temperature control processor (304) through a data transmission line; the temperature control processor (304) and the hot oven (302) are respectively connected with the radio frequency power amplifier driver (303) through data transmission lines.
4. The device for measuring the magnetic field without the blind area based on the laser polarization modulation is characterized in that the atomic gas chamber (201) is a closed light-transmitting glass gas chamber; the magnetic field coil (402) is a three-dimensional Helmholtz magnetic field coil; the temperature control processor (304) is a single chip microcomputer.
5. The measurement method of the laser polarization modulation-based blind-area-free magnetic field measurement device according to any one of claims 1 to 4, characterized by comprising the following steps:
s1, assembling the non-blind-area magnetic field measuring device based on laser polarization modulation according to a laser passing sequence and a connection relation between components;
s2, the laser (102) emits ray polarized laser under the driving of a laser controller (101); the linear polarization laser is divided into a reference beam and a main beam after passing through a polarization beam splitter (104); the first photoelectric detector (105) is arranged on the light path of the reference beam and used for feeding back a laser control signal to the laser controller (101), so that the laser controller (101) can select and stabilize the laser frequency and power; the second half wave plate (106) is used for adjusting the direction of the main polarization axis of the main beam laser before entering the liquid crystal polarization rotator (107) so that the direction of the main polarization axis of the laser falls in the central area of the control range of the liquid crystal polarization rotator (107); the main beam laser covers the atomic gas chamber (201) after passing through the beam expanding system (110); the size of a light spot of the transmitted laser passing through the focusing system (111) is smaller than that of a photosensitive surface of the second photoelectric detector, the transmitted laser passes through the second reflecting mirror (112) and then is received by the second photoelectric detector (113), an optical signal is converted into an electric signal, and the electric signal is transmitted to the data processing terminal (502) through the digital-to-analog/analog-to-digital conversion circuit (501);
s3, the data processing terminal (502) sends a magnetic field control signal to a magnetic field driving source (401); the magnetic field driving source (401) generates an alternating excitation magnetic field required by the atomic gas chamber (201) according to the magnetic field control signal;
s4, the temperature control processor (304) adjusts the output current of the radio frequency power amplifier driver (303) in real time according to the measured temperature returned by the temperature measuring resistor (301), so that the temperature of the atomic gas chamber (201) is stabilized within the range of +/-1 ℃ of the preset temperature;
s5, the data processing terminal (502) sends a liquid crystal polarization signal to the liquid crystal polarization rotator driver (108), and the main beam laser polarization direction passing through the liquid crystal polarization rotator (107) is rotated by regulating and controlling the output control voltage of the liquid crystal polarization rotator driver (108) so as to realize the dynamic adjustment of the main beam laser polarization direction;
and S6, resolving by the data processing terminal (502) according to the electric signal input by the second photoelectric detector (113) and the liquid crystal polarization signal sent to the liquid crystal polarization rotator driver (108) to obtain the magnetic field strength and the azimuth information to be measured.
6. The measuring method according to claim 5, wherein the preset temperature in step S4 is 40-100 ℃.
7. The measurement method according to claim 6, wherein the liquid crystal polarization signal in step S5 is a square wave signal for periodically adjusting the liquid crystal polarization rotator (107); when the square wave is at a low level, the square wave is dynamically adjusted, and the polarization direction of the transmission laser does not deflect; when the square wave is at a high level, the transmitted laser polarization direction produces a 45 ° rotation.
8. The measurement method according to claim 7, wherein the low level is 0v; the high level is 2.0-2.5V.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8421455B1 (en) * | 2008-09-26 | 2013-04-16 | Southwest Sciences Incorporated | Pulsed free induction decay nonlinear magneto-optical rotation apparatus |
| JP2013134086A (en) * | 2011-12-26 | 2013-07-08 | Seiko Epson Corp | Magnetic field measuring device |
| JP2016109665A (en) * | 2014-12-02 | 2016-06-20 | セイコーエプソン株式会社 | Magnetic field measurement method and magnetic field measurement device |
| FR3083876A1 (en) * | 2018-07-16 | 2020-01-17 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | VECTOR MAGNETOMETER IN ALIGNMENT WITH TWO DIFFERENTLY POLARIZED PROBE BEAMS |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101624482B1 (en) * | 2014-10-24 | 2016-05-26 | 한국표준과학연구원 | Atomic Magnetometer And Operating Method Of The Same |
| US9964604B2 (en) * | 2014-11-12 | 2018-05-08 | Seiko Epson Corporation | Magnetic field measurement method and magnetic field measurement device for measuring and offsetting original magnetic field |
| CN104698404B (en) * | 2015-03-02 | 2018-07-17 | 北京大学 | A kind of atom Magnetic Sensor for full light optical pumped magnetometer |
| CN110849849A (en) * | 2019-11-07 | 2020-02-28 | 南京理工大学 | Rapid modulation fluorescence polarization microscopic imaging device and method based on liquid crystal |
| CN110988759A (en) * | 2019-11-29 | 2020-04-10 | 山东航天电子技术研究所 | Omnidirectional magneto-optical pump magnetometer |
| CN111273205B (en) * | 2020-03-25 | 2020-12-22 | 中国人民解放军军事科学院国防科技创新研究院 | Three-dimensional space magnetic field mapping device based on atomic magnetometer |
| CN112946542B (en) * | 2021-02-02 | 2022-01-25 | 中国人民解放军军事科学院国防科技创新研究院 | Self-excitation atomic magnetic detection device and detection method based on single beam |
| CN113625206A (en) * | 2021-08-09 | 2021-11-09 | 中国人民解放军军事科学院国防科技创新研究院 | Dynamic mode conversion atomic magnetic field detection device |
-
2021
- 2021-12-16 CN CN202111543400.3A patent/CN114217249B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8421455B1 (en) * | 2008-09-26 | 2013-04-16 | Southwest Sciences Incorporated | Pulsed free induction decay nonlinear magneto-optical rotation apparatus |
| JP2013134086A (en) * | 2011-12-26 | 2013-07-08 | Seiko Epson Corp | Magnetic field measuring device |
| JP2016109665A (en) * | 2014-12-02 | 2016-06-20 | セイコーエプソン株式会社 | Magnetic field measurement method and magnetic field measurement device |
| FR3083876A1 (en) * | 2018-07-16 | 2020-01-17 | Commissariat A L'energie Atomique Et Aux Energies Alternatives | VECTOR MAGNETOMETER IN ALIGNMENT WITH TWO DIFFERENTLY POLARIZED PROBE BEAMS |
Non-Patent Citations (3)
| Title |
|---|
| Design and optimization of multilayer cylindrical magnetic shield for SERF atomic magnetometer application;Li J;《IEEE Sensors Journal》;20191231;全文 * |
| 基于非对称光子自旋—轨道相互作用的超构表面;张飞;《光电工程》;20201231;全文 * |
| 小型化原子磁场测量关键技术研究;孙晓洁;《量子光学学报》;20181231;全文 * |
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