• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a magnetometer with optical pumping and isotropic measurement. The magnetometer is all optical in the sense that the resonance between Zeeman sub-levels is induced by modulating the intensity or frequency of the pump beam. The resonance is detected either by means of the pump beam itself or by means of an unmodulated probe beam. The pump beam is polarized rectilinearly and its polarization direction is kept constant with respect to the direction of the magnetic field to be measured, so as to allow a measurement independent of the field orientation.
    公开号:FR3038730A1
    申请号:FR1556485
    申请日:2015-07-08
    公开日:2017-01-13
    发明作者:Sophie Morales；Mathieu Baicry；Francois Bertrand；Prado Matthieu Le；Jean-Michel Leger；Umberto Rossini；Jaroslaw Rutkowski
    申请人:Commissariat a lEnergie Atomique CEA；Commissariat a lEnergie Atomique et aux Energies Alternatives CEA；
    IPC主号:
    专利说明:

    MAGNETOMETER ALL OPTICAL AND ISOTROPIC DESCRIPTION
    TECHNICAL AREA
    The present invention generally relates to the field of optically pumped magnetometers.
    STATE OF THE PRIOR ART
    Optical pumping magnetometers have been known for several decades. They are based on magnetic resonance between Zeeman sub-levels, amplified using optical pumping. For example, in a magnetometer of this type using a helium cell (4He) the helium atoms at level 1¾ are excited at the metastable level 23Si by means of an HF discharge. This metastable level 23Si is divided into a Zeeman triplet in the presence of a static magnetic field. The atoms of the 23Si level are optically pumped to the 23Po level using a tunable laser. This results in a different depletion of the different sub-levels of the triplet, by selective excitation at the 23Po level. The excited atoms return by spontaneous emission at the 23Si metastable level. Magnetic resonance between the triplet levels is induced by an RF field at the Larmor frequency. The amplitude of the resonance signal is amplified by optical pumping. The resonance is observed by means of an absorption peak of the laser beam at the output of the cell. In practice, the generator of the RF field is frequency-controlled on the absorption peak by means of a PLL loop, and the modulus of the magnetic field is deduced directly from the resonant frequency F from the Larmor relation B0 = (2π / γ) Ρ where γ is the gyromagnetic ratio of the electron. Such a magnetometer measuring the modulus of the magnetic field is also called a scalar magnetometer in the literature.
    In practice, optically pumped magnetometers are highly anisotropic.
    Indeed, extinctions of the measurement signal occur for certain orientations of the sensor with respect to the direction of the magnetic field to be measured.
    Various solutions have been proposed to overcome this measurement anisotropy.
    Patent EP-B-579537 in the name of the present applicant describes an optically pumped magnetometer comprising a cell filled with helium, a laser emitting a beam at a wavelength tuned to the difference in energy between the levels 23Po and 23Si of 4He (OD line), a polarizer for linearly polarizing the beam before it is injected into the cell and a photodetector receiving the beam having passed through the cell. The magnetometer also includes a discharge circuit passing the helium atoms from the ground level 11So to the 23Si metastable level by means of an electrostatic discharge between two electrodes placed on the cell. Finally, an RF frequency generator supplies current to two coils of orthogonal axes surrounding the cell so as to generate an RF magnetic field within the cell. The axes of the two coils and the direction of propagation of the beam are chosen so as to form a rectangle trihedron.
    In this magnetometer, the measurement anisotropy is overcome by controlling the polarization direction of the beam on the one hand and the direction of the RF magnetic field on the other hand so that they are all two in the plane orthogonal to the magnetic field to be measured. The control of the polarization direction is achieved by means of synchronous detection at the Larmor frequency.
    A first variant of this magnetometer has been described in patent EP-B-656545 also in the name of the present applicant. According to this variant, the rectilinear polarizer and the RF coils are rendered mechanically integral so that the direction of polarization is always parallel to the direction of the RF magnetic field. The assembly consisting of the polarizer and the RF coils is rotated by a non-magnetic motor, the rotational servo being provided by a synchronous detection at the Larmor frequency.
    A second variant of this magnetometer has been described in patent FR-B-2984519. This second variant has the advantage of requiring no rotating part or angular position encoder, the polarization direction of the pump beam being controlled by means of a liquid crystal polarization rotator and that of the RF magnetic field being controlled by the currents supplying the induction coils.
    Although having followed a remarkable evolution, the optically pumped magnetometers of the prior art still have certain disadvantages.
    First, it is necessary to control the direction of the RF field so that it is perpendicular to the external magnetic field to be measured. Controlling the direction of the field requires either the use of complex mechanical systems with angular encoder, or additional calculations to obtain the supply currents in the RF coils.
    In addition, the use of an RF field to observe the resonance greatly complicates the networking of the magnetometers, the RF field generated by a magnetometer may disturb the measurement made by another magnetometer if they are close to one of the other (problem of crosstalk between neighboring magnetometers).
    The object of the present invention is therefore to provide an optically pumped magnetometer not having the aforementioned drawbacks. In particular, the present invention aims to provide an optical pump magnetometer, isotropic, simple and robust, not requiring control of the RF field and may be networked.
    STATEMENT OF THE INVENTION
    The present invention is defined by an optically pumped magnetometer comprising a cell filled with a gas, a laser source emitting a laser beam, a polarization module adapted to rectilinearly polarize the laser beam and to rotate the polarization so that the beam laser being biased in a polarization direction, a photodetector receiving the polarized laser beam after it has passed through the cell and providing an electrical signal, first servo means for maintaining a constant angle between the polarization direction and a magnetic field to be measured, said magnetometer further comprising modulation means for modulating at least a first portion of the laser beam so as to generate a modulated pump beam by means of a modulation frequency (fm) and second servo means for maintaining said modulation frequency equal to the Larmor frequency of the gas or one of its ha the value of the magnetic field to be measured being obtained from said modulation frequency.
    According to a first embodiment, the modulation means perform an intensity modulation at the Larmor frequency and at twice this frequency.
    In a first variant, the photodetector receives the pump beam and the electrical signal resulting from the conversion of the pump beam by the photodetector is supplied to the first and second servocontrol means.
    In a second variant, the magnetometer comprises an optical separator upstream of the polarization module to form a first part and a second part of the laser beam, the pump beam (P) being obtained by modulating the first part of the laser beam by said means of modulation, the second part of the laser beam forming a probe beam (S), unmodulated by said modulation means, the electrical signal resulting from the conversion of the probe beam being supplied to the first and second servo means.
    In a first configuration, the probe beam and the pump beam are parallel and separated by a distance less than the diffusion length of the gas atoms in the cell.
    According to a second configuration, the probe beam and the pump beam intersect in the cell at an angle substantially less than 90 °, preferably less than 10 ° or even 5 °.
    The first servocontrol means advantageously perform a demodulation at the Larmor frequency.
    The second servocontrol means preferably perform an amplitude detection on the top of the DC line, the antisymmetric error signal being obtained by a harmonic demodulation of a second modulation frequency (fm0d_BF) superimposed on the frequency modulation (fm).
    The modulation means may be constituted by an acousto-optic modulator. Alternatively, they may be constituted by an electro-optical modulator.
    When the laser source a laser diode, the magnetometer may comprise third servo means receiving said electrical signal and controlling the supply current and / or the temperature of the laser diode so that the laser beam has a length of constant wave.
    According to a second embodiment, the modulation means perform a frequency modulation at the Larmor frequency.
    The modulation means comprise, for example, an AC / DC coupler for superimposing a modulation current on the laser supply current.
    The first servocontrol means advantageously perform a demodulation at the Larmor frequency.
    The second servocontrol means preferably perform an amplitude detection on the top of the DC line, the antisymmetric error signal being obtained by a harmonic demodulation of a second modulation frequency (fm0d_BF) superimposed on the frequency modulation (fm).
    When the laser source is a laser diode, the magnetometer may comprise third servo means receiving said electrical signal and controlling the supply current and / or the temperature so that the carrier frequency of the laser beam is constant.
    BRIEF DESCRIPTION OF THE DRAWINGS Other characteristics and advantages of the invention will appear on reading a preferred embodiment of the invention with reference to the appended figures among which:
    Fig. 1 schematically represents an all-optical and isotropic magnetometer, according to a first embodiment of the invention;
    Fig. 2 schematically represents an all-optical and isotropic magnetometer, according to a variant of the first embodiment;
    Fig. 3 diagrammatically represents an all-optical and isotropic magnetometer, according to a second embodiment of the invention;
    Fig. 4 shows an example of a wavelength modulation circuit of the laser in FIG. 3.
    DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS
    The basic principle of the present invention is to induce a resonance between the Zeeman sub-levels purely optically instead of the resonance induced by the RF field in the prior art.
    According to a first embodiment of the invention, the resonance is induced by an intensity modulation of the pump beam.
    According to a second embodiment of the invention, the resonance is induced by a modulation of the wavelength of the pump beam.
    Whatever the embodiment, the isotropy of the measurement is ensured by maintaining constant the angle between the polarization direction of the pump beam and the direction of the magnetic field to be measured.
    Fig. 1 schematically represents a first embodiment of an all-optical and isotropic magnetometer according to a first embodiment of the invention.
    This magnetometer, 100, comprises a cell 110 filled with gas, for example helium or an alkaline gas. A gas whose atoms have a zero nuclear spin (even number of nucleons) is preferably chosen, the Larmor frequency then being directly proportional to the magnetic field to be measured. For reasons of simplification of the presentation, and without loss of generality, we will assume in the following description that the gas used is 4He.
    An HF discharge circuit, 115, makes it possible to pass the atoms from the ground level 1¾ to the metastable level 23Si by means of a high frequency discharge between two electrodes placed on either side of the cell. The metastable level 23Si splits into a Zeeman triplet in the presence of the magnetic field to be measured, B0.
    A laser 150 emits a beam at a wavelength tuned to the energy difference between the levels 23P0 and 23Si. This beam is modulated by means of, for example, an acousto-optic modulator or an electro-optical modulator, 180. The intensity of the modulated beam can be expressed as:
    (1) where I0 is the intensity of the unmodulated laser beam, ε is the modulation depth and fm is the modulation frequency.
    The beam thus modulated is then polarized by means of a polarization module, 130, consisting of a rectilinear polarizer, 131, and a nematic liquid crystal polarization rotator, 135. Alternatively, the polarization module may comprise a polarization module. rectilinear polarizer mounted on an orientable support rotated by a non-magnetic motor, for example a piezoelectric motor. Whatever the embodiment of the polarization module, it makes it possible to orient the polarization of the beam in any direction orthogonal to its direction of propagation so as to maintain constant the angle between the direction of polarization of the pump beam and the direction of the magnetic field and this regardless of the orientation of the sensor.
    The laser beam makes it possible to carry out an optical pumping of the 23Si metastable level at the excited level 23Po. The intensity modulation of the beam is carried out at a frequency fm equal to the frequency of Larmor
    or at a harmonic of this frequency (for example
    . The intensity modulation of the laser beam at the Larmor frequency (or a harmonic of this frequency) makes it possible to induce a resonance between the Zeeman sub-levels of the metastable level.
    After interacting with the gas of the cell, the laser beam is converted into an electrical signal by a photodetector, 170.
    The resonance is evidenced by means of a first demodulation module, 140, for controlling the polarization direction of the laser beam perpendicular to the magnetic field B0, and a second demodulation module, 160, to enslave the modulation frequency of the optical intensity of the laser beam.
    The first demodulation module 140 receives the signal from the photodetector 170 and demodulates at a first reference frequency fx supplied by the frequency synthesizer 163. The demodulator 141 is advantageously followed by a loop filter 142. in charge of controlling the servo. The signal demodulated by the demodulator 141 serves as an error signal for controlling the polarization direction in a set direction at a constant angle θ with the direction of the magnetic field B0. We will preferably choose Θ = 90 °. The error signal is of zero amplitude when the polarization direction is aligned with the desired and symmetrical direction as a function of the modulation frequency fm.
    The second demodulation module receives the signal from the photodetector 170 and demodulates at a second reference frequency f2, provided by the frequency synthesizer 163, to generate a measurement signal. The demodulator 161 is advantageously followed by a loop filter 162 (typically a low-pass filter such as an integrator). This measurement signal is an antisymmetric signal as a function of the modulation frequency fm.
    The result of the second demodulation / integration is a setpoint for controlling the generation of the modulation frequency fm by the frequency synthesizer 163. The setpoint is proportional to the frequency of Larmor and can be converted to provide the value. of the magnetic field. The intensity of the magnetic field B0 can be obtained from the frequency reference frequency synthesizer 163 when it is implemented in digital.
    An example of an operating point of an isotropic optically modulated all-optical magnetometer is described below (corresponding to 0 = 90 °).
    The signal sent to the acousto-optic (or electro-optic) modulator 180 is here the sum of a modulation at (λL and 2 <wt so that the intensity of the modulated optical beam can be written in the form: I (t) = / 0 [l +,, cos (2ftfLt) + ε2 cos (4iifLt) ~ (2)
    For controlling the bias direction (module 140), the demodulation consists of a synchronous detection between the signal from the photodetector and the reference signal at the frequency _ / j. The signal of interest for the module 140 is the resonance signal at the Larmorde frequency such that fl-fL.
    For the measurement of the field B0 and the servocontrol of the modulation frequency fm (module 160), the servocontrol is performed on the top of the resonance line DC and a low frequency RF fm0d_BF (typ 1kHz, modulation depth close to the width halfway up the line) is superimposed on the modulation frequency fm. The acousto-optic modulator performs a modulation at fm [l + Acos (2n.fmodBF. T)]. The low frequency modulation at fmodbf induces an amplitude modulation: an amplitude detection makes it possible to have a signal which vanishes and changes sign at resonance. The antisymmetric servo signal which cancels out at resonance is obtained by a synchronous detection performed at a harmonic of the frequency fm0d_BF * 1 kHz: f2 is therefore equal to fm0d_BF or to a harmonic of fmod_BF ·
    Optionally, the magnetometer may be equipped with a third demodulation module, 120, for tuning the wavelength of the pump laser beam on the line D0. For this, the wavelength of the laser is modulated at frequencies that do not induce resonance, for example fmodjaser ~ 10 kHz. Several types of wavelength modulation can be envisaged: direct modulation of the power supply current of the laser diode or piezoelectric actuator or electro-optical or acousto-optical wavelength (or phase) modulator. This third demodulation module 120 receives, on the one hand, the signal coming from the photodetector 170 and, on the other hand, a third reference signal at the frequency f3 = fmod laser resulting from the frequency synthesizer 163 (the frequency synthesizer a duplicated in the figure for reasons of representations). The result of this demodulation makes it possible to control the supply current and / or the temperature of the laser diode, 150, by means of a wavelength controller, 155, so as to keep the wavelength of the laser.
    Fig. 2 schematically represents an all-optical and isotropic magnetometer, according to a variant of the first embodiment.
    The elements identical to those shown in FIG. 1 bear the same reference signs. Unlike the previous variant, the magnetometer 200 dissociates the functions of optical pumping and measuring the resonance.
    More precisely, the beam emitted by the laser 150 is firstly divided by an optical coupler 137 into a pump beam P and a probe beam S.
    The pump beam P is modulated by the intensity modulator 180 before being injected into the cell 110. As in the previous variant, the intensity modulation of the pump beam induces a resonance between the Zeeman sub-levels.
    The probe beam makes it possible to detect the resonance induced by the pump beam.
    The pump beam P at the output of the intensity modulator 180 and the probe beam S are directed towards the rectilinear polarizer 131 and the polarization rotator 135 by means of optical fibers and optical collimators 191. The pair formed by the rectilinear polarizer 131 and the polarization rotator can be replaced by a rectilinear polarizer mounted on a rotatable support and driven in rotation by a non-magnetic motor.
    According to a first exemplary embodiment, the probe beam passes through the zone pumped by the pump beam. More precisely, a low angle of intersection (preferably between 0 ° and 40 ° and for example less than 10 ° or even 5 °) is preferably chosen between the pump and probe beams so as to maximize the overlap of the two beams.
    According to a second exemplary embodiment (not shown), the pump and probe beams are chosen parallel and separated by a distance less than the diffusion length of the atoms (depending on the gas pressure in the cell and the relaxation time of the atoms) .
    Whatever the embodiment, after interacting with the gas of the cell, the probe beam is converted into an electrical signal by means of the photodetector 170. As in the embodiment of FIG. 1, the signal from the photodetector may be subjected to a first demodulation at 140 to control the polarization direction of the polarizer and a second demodulation 160 to control the intensity modulation frequency of the pump beam. Optionally, a third demodulation, 120, may be provided to control, depending on the chosen embodiment, the supply current and / or the temperature of the laser diode, so as to maintain the wavelength of the laser constant.
    The embodiment variant illustrated in FIG. 2 is advantageous in that demodulations are performed from the probe beam and not the modulated pump beam. This technique makes it possible to decouple the modulation from the measurement of the resonance signal. The detection of the resonance is therefore facilitated.
    Fig. 3 diagrammatically represents an all-optical and isotropic magnetometer, according to a second embodiment of the invention.
    In this embodiment, the resonance is induced by a modulation of the wavelength of the pump beam. More specifically, the frequency of the pump beam is modulated according to:
    (2)
    where v0 is the center frequency of the absorption line used for optical pumping (corresponding to the transition frequency between the 23Si and 23Po levels), Ava is the offset between the carrier frequency and the center frequency of the absorption line , Avm is the modulation depth and fm is the frequency modulation frequency. It is advantageous to choose the modulation frequency equal to the Larmor frequency, either fm-fL or to one of its harmonics (for example fm-fL / 2 or fm-2fL).
    Elements with the same reference signs as in Fig. 1 or 2, are identical to those already described. Unlike the first embodiment, the magnetometer 300 does not include an intensity modulator 180 (acousto-optic or electro-optical). The laser diode 150 is powered via an AC / DC coupler 190 for modulating the supply current around a given operating point.
    Fig. 4 represents an example of a power supply circuit of a laser diode, 450. This circuit comprises a DC power supply source, 410, a current generator, 420, generating an AC current having a determined temporal function, a circuit RLC, 430 acting as an AC / DC coupler (bias-T), a temperature controller 440 and said laser diode 450. The current applied to the laser diode is none other than the sum of the DC current supplied by the source 410 and the AC current supplied by the generator 420. The modulation of the current flowing through the laser diode induces a modulation of the wavelength of the latter. Thus, in the second embodiment, there is no need to provide an external modulator.
    As in the first embodiment, the magnetometer comprises a first demodulation module, 140, for demodulating the signal from the photodetector at a first reference frequency _ / j. This demodulation makes it possible to control the direction of polarization of the laser beam, by the polarization rotator 135, so that it has a constant angle (preferably 0 = 90 °) with the magnetic field to be measured. As previously, the pair formed by the rectilinear polarizer 131 and the polarization rotator 135 can be replaced by a rectilinear polarizer mounted on a rotatable support and can be rotated by a non-magnetic motor.
    The magnetometer also comprises a second demodulation module, 160, for demodulating the signal from the photodetector at a second reference frequency f2. This demodulation makes it possible to slave the modulation frequency of the laser beam fm so as to create a resonance between the Zeeman sub-levels. Advantageously, the modulation frequency will be slaved to the Larmor frequency, ie fm-fL, and the synchronization detection polarization direction will be selected at / j = fL (more specifically, the error signal for controlling the polarization direction of the laser beam is the quadrature resonance signal detected at the Larmor frequency.This signal is symmetrical as a function of the modulation frequency, vanishes for the angle Θ = 90 ° and is antisymmetric around Θ = 90 °). In addition, the signal for measuring and controlling the modulation frequency is that obtained by synchronous detection at f2 = 2 * fmod BF ~ 2 kHz. The resonance signal is the continuous signal on which a low frequency modulation is added to fm0d_BF An amplitude detection makes it possible to obtain an error signal. The antisymmetrical signal which makes it possible to slave the modulation frequency is the resonance signal on the harmonic 2 of fmod_BF.
    Optionally, it will be possible, as previously, to provide a third demodulation module, 120, for controlling the wavelength of the laser diode, via the laser controller 155, so that the carrier frequency v0 + Ava is maintained. at a constant value. For this, a complementary modulation
    can be superimposed on previous modulations.
    权利要求:
    Claims (16)
    [1" id="c-fr-0001]
    An optically pumped magnetometer comprising a gas filled cell (110), a laser beam emitting laser source (150), a polarization module (130) adapted to linearly polarize the laser beam and rotate the polarization thereof for the laser beam to be polarized in a polarization direction, a photodetector (170) receiving the polarized laser beam after it has passed through the cell and providing an electrical signal, first servo means (140) for maintaining an angle constant between the polarization direction and a magnetic field to be measured, characterized in that it further comprises modulation means (180, 190) for modulating at least a first portion of the laser beam so as to generate a modulated pump beam by means of a modulation frequency (fm) and second servo means (160) for maintaining said modulation frequency equal to the Larmor frequency of the gas or one its harmonics, the value of the magnetic field to be measured being obtained from said modulation frequency.
    [2" id="c-fr-0002]
    Optical pumping magnetometer according to claim 1, characterized in that the modulation means (180) perform intensity modulation at the Larmor frequency and twice that frequency.
    [3" id="c-fr-0003]
    Optical pump magnetometer according to Claim 2, characterized in that the photodetector (170) receives the pump beam and the electrical signal resulting from the conversion of the pump beam by the photodetector is supplied to the first and second servo means. (140.160).
    [4" id="c-fr-0004]
    4. Optical pump magnetometer according to claim 2, characterized in that it comprises an optical separator (137) upstream of the polarization module (130) to form a first portion and a second portion of the laser beam, the beam pump [ P) being obtained by modulating the first part of the laser beam by said modulating means, the second part of the laser beam forming a probe beam (S), unmodulated by said modulating means, the electrical signal resulting from the conversion of the probe beam being provided to the first and second servo means (140, 160).
    [5" id="c-fr-0005]
    Optical pumping magnetometer according to claim 4, characterized in that the probe beam and the pump beam are parallel and separated by a distance less than the diffusion length of the gas atoms in the cell.
    [6" id="c-fr-0006]
    6. optically pumped magnetometer according to claim 4, characterized in that the probe beam and the pump beam intersect in the cell at an angle substantially less than 90 °, preferably less than 10 ° or even 5 °.
    [7" id="c-fr-0007]
    7. optically pumped magnetometer according to one of the preceding claims, characterized in that the first servocontrol means (140) perform a demodulation at the Larmor frequency.
    [8" id="c-fr-0008]
    Optical pumping magnetometer according to one of the preceding claims, characterized in that the second servocontrol means (160) perform an amplitude detection on the top of the DC line, the antisymmetric error signal being obtained by a harmonic demodulation of a second modulation frequency (fmod BF) superimposed on the modulation frequency (fm).
    [9" id="c-fr-0009]
    9. optically pumped magnetometer according to one of claims 2 to 8, characterized in that the modulation means are constituted by an acousto-optic modulator.
    [10" id="c-fr-0010]
    10. optical pump magnetometer according to one of claims 2 to 8, characterized in that the modulation means are constituted by an electro-optical modulator.
    [11" id="c-fr-0011]
    11. optically pumped magnetometer according to one of the preceding claims, characterized in that the laser source is a laser diode and comprises third servo means (120) receiving said electrical signal and controlling the supply current and / or the temperature of the laser diode so that the laser beam has a constant wavelength.
    [12" id="c-fr-0012]
    12. Optical pumping magnetometer according to claim 1, characterized in that the modulation means perform a frequency modulation at the Larmor frequency.
    [13" id="c-fr-0013]
    Optical pumping magnetometer according to claim 12, characterized in that the modulating means comprise an AC / DC coupler (190) for superimposing a modulation current on the laser supply current.
    [14" id="c-fr-0014]
    14. optically pumped magnetometer according to one of claims 12 or 13, characterized in that the first servocontrol means (140) perform a demodulation at the Larmor frequency.
    [15" id="c-fr-0015]
    Optical pumping magnetometer according to one of Claims 12 to 14, characterized in that the second servocontrol means (160) perform an amplitude detection on the top of the DC line, the antisymmetric error signal being obtained by a harmonic demodulation of a second modulation frequency (fmod BF) superimposed on the modulation frequency (fm).
    [16" id="c-fr-0016]
    Optical pumping magnetometer according to one of Claims 12 to 15, characterized in that the laser source is a laser diode and comprises third servocontrol means (120) receiving said electrical signal and controlling the current. supply and / or temperature so that the carrier frequency of the laser beam is constant.
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    同族专利:
    公开号 | 公开日
    US20170010337A1|2017-01-12|
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    EP3115799B1|2017-08-23|
    FR3038730B1|2017-12-08|
    US10371764B2|2019-08-06|
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    优先权:
    申请号 | 申请日 | 专利标题
    FR1556485A|FR3038730B1|2015-07-08|2015-07-08|MAGNETOMETER ALL OPTICAL AND ISOTROPIC|FR1556485A| FR3038730B1|2015-07-08|2015-07-08|MAGNETOMETER ALL OPTICAL AND ISOTROPIC|
    EP16178106.7A| EP3115799B1|2015-07-08|2016-07-06|Isotropic and all-optical magnetometer|
    US15/204,230| US10371764B2|2015-07-08|2016-07-07|All-optical and isotropic magnetometer|
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