Light intensity controller and atomic magnetometer system

Abstract

This invention relates to the field of quantum precision magnetic field measurement technology, and discloses a light intensity controller and an atomic magnetometer system. The light intensity controller includes a housing, a light intensity regulating component, and a driver. The housing has a beam channel, and an inlet, an outlet, and a dimming port connecting the beam channel. The light intensity regulating component is located at the dimming port and includes a rotating shaft and a first light-blocking plate. The rotating shaft is perpendicular to the beam channel and offset from the beam passing through the beam channel. The first light-blocking plate is located on the rotating shaft to block the beam. The driver is located on the housing and is drively connected to the rotating shaft. The rotating shaft has a first angular range within which the first light-blocking plate blocks the beam, and the blocking area is linearly related to the rotation angle of the rotating shaft. This invention meets the requirement of linear dimming, effectively reduces the risk of stalling, has high integration, and can more reliably complete the precise adjustment of laser light intensity in an atomic magnetometer system, making it suitable for application in atomic magnetometer systems.

Description

Technical Field

[0001] This invention relates to the field of quantum precision magnetic field measurement technology, specifically to a light intensity controller and an atomic magnetometer system. Background Technology

[0002] Atomic magnetometers utilize the interaction between light and atoms to measure magnetic fields and have been widely used in the field of quantum precision measurement instruments and scientific equipment. For example, atomic magnetometers based on the spin-exchange relaxation-free (SERF) principle are not affected by spin exchange relaxation, have high-precision measurement capabilities, and are non-invasive, radiation-free, non-contact, operate at room temperature, have high sensitivity, and high time resolution, making them highly valuable for research and application in cardiac and cerebrovascular magnetic medicine.

[0003] In practical operation, multi-channel atomic magnetometers require real-time control of the light intensity of the detection laser in each channel to ensure that the atomic clusters interacting with the laser achieve optimal polarization efficiency and improve the system's measurement signal-to-noise ratio.

[0004] In related technologies, the light intensity controller of the atomic magnetometer system uses a rotating motor to drive the linear movement of the light-blocking plate to block light and reduce the amount of light transmitted. This method has disadvantages such as poor adjustment linearity, easy stalling, and wear that can introduce dirt, which affects the service life and reliability of the atomic magnetometer system.

[0005] Meanwhile, the driving laser of the atomic magnetometer system uses a polarized laser. If a thread-based optical intensity controller is used, it is difficult to guarantee the alignment accuracy of the polarization-maintaining fiber, resulting in an extinction ratio of less than 23dB. However, the driving laser of the SERF atomic magnetometer system is above 30dB, which results in a strong depolarization property of the optical intensity controller, thus affecting the polarization degree of the overall optical path and the measurement accuracy of the atomic magnetometer system.

[0006] In addition, in the multi-channel atomic magnetometer system of related technologies, each channel is equipped with a light intensity controller, which will result in drawbacks such as larger light intensity control module size, increased control difficulty, and increased cost, which is not conducive to the expansion of the number of array sensor channels and the development of lightweight equipment. Summary of the Invention

[0007] In view of this, the present invention provides a light intensity controller and an atomic magnetometer system to solve the problem of poor reliability of dimming methods.

[0008] In a first aspect, the present invention provides a light intensity controller, comprising a housing, a light intensity regulating component, and a driver. The housing is provided with a beam channel, and an inlet, an outlet, and a dimming port communicating with the beam channel. The light intensity regulating component is disposed in the dimming port and includes a rotating shaft and a first light-blocking plate. The rotating shaft is perpendicular to the beam channel and offset from the beam passing through the beam channel. The first light-blocking plate is disposed on the rotating shaft for blocking the beam. The driver is disposed on the housing and is kinetically connected to the rotating shaft for driving the rotating shaft to rotate. The rotating shaft has a first angle range, within which the first light-blocking plate blocks the beam, and the blocking area is linearly related to the rotation angle of the rotating shaft.

[0009] Beneficial effects: On the one hand, the present invention achieves dimming through rotation, thereby reducing transmission links, increasing integration, reducing the risk of stalling and the generation of contaminants, and facilitating dynamic sealing between the dimming port and the rotating shaft, reducing the risk of contaminants entering the beam channel; on the other hand, this also makes the shape design of the first light-blocking plate suitable, so that the light-blocking area and the rotation angle are linearly related within a certain range, meeting the requirements of linear dimming. Therefore, the light intensity controller can more reliably complete the precise adjustment of the laser light intensity in the atomic magnetometer system, making it suitable for application in atomic magnetometer systems.

[0010] In one alternative embodiment, the first light-blocking sheet includes a light-shielding surface, which is a cylindrical surface parallel to the axis of rotation.

[0011] Beneficial effects: The light-shielding surface adopts a cylindrical design. By making the guideline of the cylinder satisfy the set functional relationship, the effect of linear correlation between the blocking area and the corner is achieved, thereby reducing the processing difficulty of the first light-blocking sheet and making the first light-blocking sheet suitable for miniaturization.

[0012] In one optional embodiment, the light-shielding surface includes a generatrix and a collimator. The generatrix is ​​parallel to the axis of rotation, and its length is M. The beam spot diameter is D, and the generatrix satisfies M > D. The collimator is perpendicular to the axis of rotation, and the distance from any point on the collimator to the axis of rotation is N. The distance from the optical axis of the beam to the axis of rotation is H. The collimator satisfies... , .

[0013] Beneficial effects: By setting M > D, it helps to eliminate the influence of the busbar length on the light-blocking area and avoids interfering with the shape design of the guideline; by setting , This allows the occlusion area to change linearly between a completely unoccluded state and a completely occluded state, better meeting the needs of linear dimming.

[0014] In one alternative implementation, the range of the first angle interval is greater than or equal to 50°.

[0015] Beneficial effects: Setting a linear correlation range greater than 50° helps improve the adjustment precision of the light intensity controller, so that the light intensity controller can more reliably complete the precise adjustment of the laser light intensity in the atomic magnetometer system.

[0016] In one alternative implementation, the driver includes a stepper motor, wherein the occlusion area and the pulse quantity of the stepper motor are linearly related within the first angular range.

[0017] Beneficial effects: The shape of the first light-blocking sheet is obtained by sampling and fitting. In other words, when designing the first light-blocking sheet, the angle change value corresponding to a pulse is used as the interval between sampling points. This reduces the manufacturing difficulty and cost of the light intensity control component without affecting the actual use effect, and improves the feasibility of the light intensity controller. Furthermore, the light-blocking area and the pulse signal of the control circuit are linearly related, making it easier to control the light-blocking area.

[0018] In one alternative embodiment, a plurality of reduction modules are further included, which are detachably connected between the driver and the rotating shaft, and the number of reduction modules connected is adjustable.

[0019] Beneficial effects: By setting up a modular and detachable reduction module, the transmission ratio between the driver and the shaft can be changed according to the control precision requirements, making the rotation control of the shaft more flexible.

[0020] In one optional embodiment, the light intensity adjustment element further includes a second light-blocking plate, which is disposed on the rotating shaft and at an angle to the first light-blocking plate, and the second light-blocking plate is provided with an aperture for light transmission.

[0021] Beneficial effects: In some scenarios with specific light intensity requirements, the beam can be adjusted to the required shape and intensity using a pre-designed aperture, which can not only meet the light intensity control requirements, but also eliminate stray light at the edge of the beam and improve the accuracy of measurements in atomic magnetometer systems.

[0022] In one alternative embodiment, the system further includes a first collimator, a second collimator, and a polarizing actuator. The first collimator and the second collimator are disposed on the housing and aligned with the entrance port and the exit port, respectively. The polarizing actuator is disposed within the beam channel and integrated into the end face of the first collimator.

[0023] Beneficial effects: The first collimator forms a collimated beam that passes through the beam channel. After passing through the polarizer and the intensity modulator, the beam enters the second collimator. By incorporating the polarizer into the intensity controller, it helps to improve the polarization extinction ratio of the intensity controller and enhance the polarization degree of the pump / detection laser incident on the atomic magnetometer. It is suitable for fiber optic atomic magnetometers and array-type atomic magnetometer systems, improving the sensitivity and accuracy of magnetic field measurements.

[0024] Secondly, the present invention also provides an atomic magnetometer system, including a laser, an atomic magnetometer, and a light intensity controller provided by the present invention, wherein the light intensity controller is located downstream of the laser and the atomic magnetometer is located downstream of the light intensity controller.

[0025] Beneficial effects: The atomic magnetometer system includes the light intensity controller provided by this invention, and therefore has the corresponding beneficial effects brought by the light intensity controller, which will not be elaborated here.

[0026] In one optional embodiment, the atomic magnetometers are multiple, and the atomic magnetometer system further includes a beam splitter located between the light intensity controller and the atomic magnetometers, for causing the emitted light from the light intensity controller to be incident on each of the atomic magnetometers respectively.

[0027] Beneficial effects: By placing the light intensity controller before the beam splitter, the number of light intensity controllers can be reduced in multi-channel application scenarios, reducing the difficulty of light intensity control and improving the consistency of light intensity. At the same time, installing the light intensity controller before the beam splitter of the multi-channel atomic magnetometer can significantly reduce the number of light intensity controllers in the atomic magnetometer system, saving costs and reducing control difficulty and failure rate.

[0028] In addition, installing the light intensity controller in front of the beam splitter of the multi-channel atomic magnetometer can effectively avoid power drift of the laser caused by temperature changes or mechanical vibration, ensuring the long-term stable operation of the atomic magnetometer system. Attached Figure Description

[0029] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the structure of a light intensity controller according to an embodiment of the present invention;

[0031] Figure 2This is a cross-sectional schematic diagram of a light intensity controller according to an embodiment of the present invention;

[0032] Figure 3 This is a top view schematic diagram of the light intensity adjustment component according to an embodiment of the present invention;

[0033] Figure 4 This is a front view schematic diagram of the light intensity adjustment component according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram illustrating the adjustment effect of the light intensity regulating component according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of an atomic magnetometer system according to an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Main controller; 2. Laser; 3. Beam splitter; 4. Intensity controller; 401. Driver; 402. Reduction module; 404. First sheath; 405. Second sheath; 406. Fiber optic sleeve; 407. Housing; 4071. Main housing; 4072. Cover plate; 408. Intensity adjustment component; 4081. Rotating shaft; 4082. First light-blocking plate; 4083. Second light-blocking plate; 409. First collimator; 410. Polarization polarizer; 411. Second collimator; 5. Coupler; 6. Atomic magnetometer; 7. Intensity controller slave unit; 8. Data acquisition module. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a," "an," and "comprising" as used herein may also mean including the plural forms. The terms "comprising," "including," and "having" are inclusive and therefore indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0040] Although terms such as "first," "second," etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Furthermore, in the description of this invention, unless otherwise expressly specified and limited, the terms "set up" and "connected" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a direct connection or an indirect connection via an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "end," "length," "inner," "outer," etc. Such spatial relative terms are intended to include different orientations of the mechanism in use or operation, in addition to those depicted in the figure. For example, if the mechanism in the figure is flipped, then an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The mechanism may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0042] Atomic magnetometer systems offer high-precision measurements and are characterized by being non-invasive, radiation-free, non-contact, operating at room temperature, highly sensitive, and having high time resolution. In related technologies, the light intensity controller in atomic magnetometer systems uses a rotating motor to drive a linear motion of a light-blocking plate, which suffers from drawbacks such as susceptibility to stalling, potential for contamination, and unsuitability for linearization.

[0043] On the one hand, the rotating motor needs to convert the rotational motion of the output shaft into the linear motion of the light-blocking plate through a transmission mechanism (screw-slider mechanism or gear and rack mechanism). Taking the screw-slider mechanism as an example, as the light-blocking plate moves, the meshing part of the screw and slider also changes, which is not conducive to designing dynamic seals for the transmission mechanism. The dirt generated during the transmission process (such as lubricating oil or wear debris) can easily contaminate the light path of the light intensity controller. If the lubrication is not sufficient, problems such as stalling and jamming can easily occur, hindering the normal movement of the light-blocking plate.

[0044] On the other hand, the range of motion of a linearly moving light-blocking plate is limited to a two-dimensional plane, and the adjustable variables are limited. Assuming that the light-blocking plate moves along the length direction, the width of the light-blocking plate needs to be made a variable in order to achieve a linear relationship between the light-blocking area and the travel. However, if the width is too small, it will affect the processing difficulty and structural stability of the light-blocking plate. Furthermore, the light-blocking plate needs to be precisely aligned to achieve linearization, resulting in poor feasibility of linear correlation.

[0045] Meanwhile, the light intensity controller of the related technology has strong depolarization, which affects the polarization degree of the overall optical path and the measurement accuracy of the atomic magnetometer system.

[0046] The following is combined Figures 1 to 6 The following describes embodiments of the present invention.

[0047] Reference Figure 1 , Figure 2 , Figure 3 , Figure 4 According to an embodiment of the present invention, a light intensity controller 4 is provided, comprising a housing 407, a light intensity regulating element 408, and a driver 401. The housing 407 is provided with a beam channel, and an inlet, an outlet, and a dimming port communicating with the beam channel. The light intensity regulating element 408 is disposed in the dimming port and includes a rotating shaft 4081 and a first light-blocking plate 4082. The rotating shaft 4081 is perpendicular to the beam channel and offset from the beam passing through the beam channel. The first light-blocking plate 4082 is disposed on the rotating shaft 4081 for blocking the beam. The driver 401 is disposed on the housing 407 and is drively connected to the rotating shaft 4081 for driving the rotating shaft 4081 to rotate. The rotating shaft 4081 has a first angle range, within which the first light-blocking plate 4082 blocks the beam, and the blocking area is linearly related to the rotation angle of the rotating shaft 4081.

[0048] Under the drive of the driver 401, the rotating shaft 4081 can rotate within a certain range (generally from 0° to 360°). The first angle range is a specific interval within the rotation range of the rotating shaft 4081 (e.g., from 10° to 70°). Within the first angle range, the first light-blocking plate 4082 is located on the optical path of the light beam, thereby partially or completely blocking the light beam and achieving the effect of light intensity modulation. In addition, it should be noted that when the rotating shaft 4081 selects different zero points as references, the starting angle and ending angle of the first angle range will change accordingly, but the range of the first angle range (i.e., the difference between the starting angle and the ending angle) remains unchanged.

[0049] This invention achieves dimming by rotating a light-blocking plate, thereby saving on the transmission mechanism, eliminating the need for threads, reducing the risk of the rotating shaft 4081 becoming stuck, and reducing mechanical wear, which helps to extend the service life of the device. At the same time, the rotating shaft 4081 only rotates and does not perform linear motion, which also facilitates the implementation of dynamic sealing between the dimming port and the rotating shaft 4081, reducing the risk of contaminants entering the beam channel, further improving the cleanliness of the beam channel, improving the beam quality transmitted in the beam channel, and ensuring the long-term reliability of the device.

[0050] On the other hand, the rotation method allows the first light-blocking sheet 4082 to move in three-dimensional space, and the shape of the first light-blocking sheet 4082 has more optional variables. This also makes the first light-blocking sheet 4082 suitable for shape design, so that the light-blocking area and the rotation angle are linearly related within a certain range, thus meeting the requirements of linear dimming.

[0051] Furthermore, the light intensity controller 4 also has the advantages of low noise, low vibration, and no upper or lower movement limits.

[0052] Therefore, the light intensity controller 4 can enhance the precision and uniformity of adjustment, and more reliably complete the light intensity adjustment of the laser.

[0053] For example, refer to Figure 3 and Figure 4 In some embodiments, the first light-blocking plate 4082 includes a light-shielding surface, which is a cylindrical surface parallel to the rotation axis 4081. It is understood that the cylindrical surface is formed by moving a generatrix along a guideline, the generatrix of the light-shielding surface being parallel to the axis of rotation 4081, and the guideline of the light-shielding surface being perpendicular to the axis. This is achieved by shaping the guideline (in...) Figure 3 (As shown in the figure) become variables, satisfying the set functional relationship, so as to achieve the effect of linear correlation between the occlusion area and the corner.

[0054] At this time, the dimensions of the first light-blocking sheet 4082 in the axial direction remain unchanged. Only the light-blocking surface that meets the requirements needs to be processed, thereby ensuring structural strength, reducing the processing difficulty of the first light-blocking sheet 4082, and making the first light-blocking sheet 4082 suitable for miniaturization.

[0055] Optionally, in some embodiments, the length of the generatrix is ​​M, the beam spot diameter is D, and the generatrix satisfies M > D; the distance from any point on the profilometry to the axis of rotation 4081 is N, and the distance from the optical axis of the beam to the axis is H, and the profilometry satisfies... , .

[0056] On the one hand, setting M > D ensures that the dimension M of the first light-blocking plate 4082 in the axial direction meets the requirement of blocking the entire beam, which helps to eliminate the influence of the generatrix length on the light-blocking area and avoids interfering with the shape design of the collimator. On the other hand, N can be expressed as a function of the rotation angle θ of the rotation axis 4081. Based on this, setting... , This allows the linear adjustment range of the light-blocking area to be from 0% (completely blocked) to 100% (completely unblocked), better meeting the needs of linear dimming.

[0057] like Figure 3 As shown, the light-shielding surface can be curved. The design and calculation principle of cam flat bottom follower is adopted. The boundary condition is that the light-shielding area changes the same for each step. The required curved surface is solved so that the light-shielding surface provides linear light intensity attenuation capability when rotating.

[0058] Specifically, refer to Figure 3 The relationship between the light-blocking area and the light-blocking length is as follows:

[0059] ;

[0060] Where S is the light-blocking area; h is the light-blocking length; and r is the beam radius. It can be understood that the shaded area is the shown obstructed area, which is the overlapping region of the projection of the light-blocking surface onto a reference plane perpendicular to the beam and the beam's beam spot. The light-blocking area S is the area of ​​the obstructed area. Since h is difficult to express as an explicit function with S as the variable, the value of h corresponding to the equal area change can be solved numerically based on the correspondence between the light-blocking area S and the light-blocking length h. For example, with r = 150 mm. Value 1000mm 2 Substitute different values ​​of S (e.g., 1000, 2000, 3000) into the formula to obtain the corresponding light-blocking length h (12.435mm, 19.840mm, 26.113mm).

[0061] After determining the light-blocking length h, since h is the projection of the directrix N onto a reference plane perpendicular to the beam, the corresponding directrix can be obtained by interpolating and fitting each light-blocking length h.

[0062] Optionally, in some embodiments, the range of the first angle interval is greater than or equal to 50°. It is understood that... This determines the dimming accuracy of the light intensity controller. The value of is affected by the light-blocking area S, the rotational accuracy of the driver 401, and the range of the first angle interval. It is positively correlated with the rotational accuracy of the driver 401 and the range of the first angle interval. A linear correlation range greater than 50° is set so that the rotating shaft 4081 needs to rotate at least 50° to complete the change in light intensity from 100% to 0%, ensuring that the light intensity controller 4 can meet the need for linear adjustment of light intensity. For example, in Figure 5 In the illustrated embodiment, the range of the first angle interval is greater than 70°. In addition, the range of the first angle interval can also be 50°, 60°, 80°, etc., and the present invention does not limit it.

[0063] Figure 5 It shows Figure 3 The blocking effect of the first light-blocking sheet 4082 in the embodiment and its comparison with related technologies.

[0064] in, Figure 5 The diagram includes four parts: A, B, C, and D. Part A shows the correspondence between the light-blocking length h and the light-blocking area S of the first light-blocking sheet 4082 of the present invention. Part B shows the increment of the light-blocking length h of the first light-blocking sheet 4082 of the present invention. The correspondence between the light-blocking area S and the light-blocking area is shown in part C, which shows the correspondence between the light-blocking area of ​​the first light-blocking plate 4082 of the present invention and the rotation angle of the rotating shaft 4081. Part D shows the correspondence between the light-blocking area of ​​the linear motion light-blocking plate using threaded drive in related technologies and the rotation angle of the motor.

[0065] It can be seen that the first light-blocking plate 4082 of the present invention can achieve good linear correlation over a wide range, overcoming the defects of linear motion light-blocking plates using threaded drives in related technologies.

[0066] Optionally, in some embodiments, the driver 401 includes a stepper motor, wherein the occlusion area and the number of pulses of the stepper motor are linearly related within a first angular range.

[0067] Understandably, as illustrated in the previous example, when designing the shape of the first light-blocking sheet 4082 based on the light-blocking area S, it is difficult to express this using an explicit functional expression with S as the variable. Therefore, it is necessary to select multiple sampling points and obtain the final shape through numerical fitting. The more sampling points there are, the more refined the fitting result will be, but the higher the processing precision requirements for the first light-blocking sheet 4082 will be.

[0068] By setting the blocking area to be linearly related to the pulse quantity of the stepper motor, that is, when designing the first light-blocking plate 4082, the angle change value corresponding to one pulse quantity is used as the interval between sampling points, the manufacturing difficulty and cost of the light intensity adjustment component 408 can be reduced without affecting the actual use effect, and the feasibility of the light intensity controller 4 can be improved. Furthermore, the linear relationship between the light-blocking area and the pulse signal of the control circuit makes it easier to control the light-blocking area.

[0069] It should be noted that the design of the light-shielding surface is not limited to the design method with the shape of the guideline as a variable as shown in the previous example. Other parameters on the first light-shielding sheet 4082 that can be used as variables can also be used, and multiple variables can be introduced at the same time for design. This invention does not limit this.

[0070] Optionally, in some embodiments, the light intensity controller 4 further includes a plurality of deceleration modules 402, which are detachably connected between the driver 401 and the rotating shaft 4081, and the number of deceleration modules 402 connected is adjustable.

[0071] On the one hand, the driver 401 drives the rotating shaft 4081 through the reduction module 402, which can improve the accuracy of the angle control of the rotating shaft 4081, thereby enabling the light intensity controller 4 to adjust the light intensity more precisely to meet the needs of high-precision application scenarios. On the other hand, multiple reduction modules 402 are set and a detachable modular installation method is adopted, so they can be flexibly assembled as needed to change the transmission ratio between the driver 401 and the rotating shaft 4081, such as 1:50, 1:100, 1:200, 1:400, 1:700, etc., making the rotation control of the rotating shaft 4081 more flexible and adaptable to the needs of different atomic magnetometer application scenarios.

[0072] For example, when the required light intensity adjustment accuracy is high, multiple reduction modules 402 can be used to obtain a relatively high transmission ratio. When the required light intensity adjustment accuracy is low, fewer reduction modules 402 can be used to increase the rotation speed of the rotating shaft 4081 while ensuring that the accuracy meets the requirements, so that the light intensity controller 4 can adjust to the position more quickly.

[0073] Specifically, in some embodiments, the reduction module 402 can use a planetary reducer. On the one hand, the planetary reducer can achieve a high transmission ratio, which helps to reduce the number of reduction modules 402 used in assembly. On the other hand, the input and output modes of the planetary reducer are flexible and varied. It can use the sun gear shaft as input or output, or it can use the ring gear as input or output, which facilitates the assembly and use of different planetary reducers.

[0074] In some embodiments, the light intensity adjustment element 408 further includes a second light-blocking plate 4083, which is disposed on the rotating shaft 4081 and at an angle to the first light-blocking plate 4082. The second light-blocking plate 4083 is provided with an aperture for light transmission.

[0075] At this time, the light intensity modulation element 408 has two different dimming modes, suitable for different application scenarios. In the first mode, the first light-blocking plate 4082 is located in the optical path of the light intensity modulation element 408, and each pulse has the same attenuation within the first angle range, realizing linearly related blocking area adjustment; in the second mode, the second light-blocking plate 4083 is located in the optical path of the light intensity modulation element 408, and the incident light exits after passing through the aperture, realizing constant blocking area adjustment.

[0076] Therefore, in some scenarios with specific light intensity requirements, the size of the aperture can be determined based on the power of the incident light and the required power of the optical path. The beam can be adjusted to the required shape and intensity using the pre-designed aperture, which can not only meet the light intensity control requirements, but also eliminate stray light at the edges and improve the accuracy of the atomic magnetometer system during measurement.

[0077] In some embodiments, the light intensity controller 4 further includes a first collimator 409 and a second collimator 411, which are disposed on the housing 407 and aligned with the entrance and exit ports, respectively. The first collimator 409 collimates the light beam from the optical fiber and outputs it to facilitate light blocking adjustment. After passing through the light intensity modulation element 408, the light beam enters the second collimator 411, and after collimation, it is coupled into the optical fiber for further downstream output, thereby obtaining an output light in which only the light intensity changes while other parameters remain unchanged.

[0078] Specifically, refer to Figure 1 In some embodiments, the light intensity controller 4 further includes a first sheath 404, a second sheath 405, and an optical fiber sleeve 406. The first sheath 404 is made of a metal material (e.g., stainless steel). Two first sheaths 404 are respectively disposed at both ends of the housing 407, corresponding to the inlet and outlet respectively. The first collimator 409 and the second collimator 411 are respectively inserted into the two first sheaths 404 for protection and positioning. The second sheath 405 is made of an elastic material (e.g., rubber). Two second sheaths 405 are respectively disposed on the two first sheaths 404. The optical fibers of the first collimator 409 and the second collimator 411 are wrapped by the second sheath 405. While protecting and supporting the optical fibers, the second sheath 405 can also compensate for assembly errors through elastic deformation to avoid damage to the optical fibers. The optical fiber sleeve 406 is disposed on the second sheath 405 to provide further protection for the optical fibers.

[0079] In some embodiments, the light intensity controller 4 further includes a polarization polarizer 410 disposed within the beam channel and integrated into the end face of the first collimator 409. The first collimator 409 forms a collimated beam passing through the beam channel. After passing through the polarization polarizer 410 and the light intensity modulation element 408, the beam enters the second collimator 411. By incorporating the polarization polarizer 410 into the light intensity controller 4, the polarization extinction ratio of the light intensity controller 4 can be improved (up to 30 dB or more), thereby increasing the polarization degree of the pump / detection laser incident on the atomic magnetometer. This is suitable for fiber-optic atomic magnetometers and array-type atomic magnetometer systems, improving the accuracy of measurements used in atomic magnetometer systems.

[0080] In some embodiments, the housing 407 includes a main housing 4071 and a cover plate 4072. The main housing 4071 is provided with a beam channel, an entrance port, and an exit port. The cover plate 4072 covers the main housing 4071 and is provided with a dimming port. The driver 401 is disposed on the cover plate 4072. Furthermore, the cover plate 4072 can be detachably disposed on the main housing 4071. When the cover plate 4072 is removed, the beam channel can be partially exposed, which is suitable for the debugging and maintenance of the light intensity controller 4.

[0081] Secondly, referring to Figure 6 The present invention also provides an atomic magnetometer system, including a laser 2, an atomic magnetometer 6, and a light intensity controller 4 provided by the present invention. The light intensity controller 4 is located downstream of the laser 2, and the atomic magnetometer 6 is located downstream of the light intensity controller 4.

[0082] In use, laser 2 is used to generate polarized light. The laser emitted by laser 2 is transmitted to light intensity controller 4 and then to atomic magnetometer 6, where it is absorbed by the alkali metal gas cell to generate a laser light intensity signal. The atomic magnetometer system includes the light intensity controller 4 provided by this invention, and therefore has the beneficial effects brought by the light intensity controller 4, which will not be elaborated here.

[0083] In one alternative embodiment, the atomic magnetometers 6 are multiple, and the atomic magnetometer system further includes a beam splitter 3 located between the light intensity controller 4 and the atomic magnetometers 6, for causing the emitted light from the light intensity controller 4 to be incident on each atomic magnetometer 6 respectively.

[0084] In some related multi-channel atomic magnetometer systems, setting up a light intensity controller for each channel results in drawbacks such as larger light intensity control module size, increased control difficulty, and increased cost, which is not conducive to expanding the number of array sensor channels and developing lightweight devices.

[0085] In the atomic magnetometer system designed in this invention, by placing the light intensity controller 4 before the beam splitter 3, the number of light intensity controllers 4 can be reduced in multi-channel application scenarios, reducing the difficulty of light intensity control and improving the consistency of light intensity. At the same time, it can also reduce the implementation cost of the atomic magnetometer system, reduce the volume occupied by the light intensity controller 4 and the failure rate, and improve the reliability of the atomic magnetometer system.

[0086] Furthermore, in a multi-channel atomic magnetometer system, the more beam splitting channels there are, the more difficult it is to ensure that the extinction ratio and power of each channel are consistent. Through improvements and optimizations to the beam splitter 3 process, the consistency of each channel can be made to meet the requirements of a single light intensity controller 4 controlling an atomic magnetometer system with 32 or 64 channels. This also ensures that the gas cells of each channel meet the operating conditions of the atomic magnetometer, allowing the light intensity controller 4 to be used in the front end.

[0087] Continue to refer to Figure 6 In some embodiments, the atomic magnetometer system further includes couplers 5, the number of which corresponds one-to-one with the atomic magnetometers 6, and are located between the beam splitter 3 and the atomic magnetometers 6. The couplers 5 further collimate the emitted light from the beam splitter 3, thereby improving the quality of the laser emitted from the atomic magnetometer 6 and improving the measurement accuracy of the atomic magnetometer system.

[0088] In some embodiments, the atomic magnetometer system further includes a main controller 1, a light intensity controller slave device 7, and a data acquisition module 8. The main controller 1 is communicatively connected to the other devices in the atomic magnetometer system and is used to control the operation of the atomic magnetometer system.

[0089] For example, in some embodiments, the atomic magnetometer system detects the value of photocurrent through a photoelectric sensor and feeds it back to the main controller 1 to achieve feedback control.

[0090] Specifically, during operation, the main controller 1 controls the laser 2 to generate polarized light with a wavelength of 795nm. The laser emitted by the laser 2 is incident on the light intensity controller 4 equipped with a driver 401 (stepper motor) via a polarization-maintaining fiber. The driver 401 controls the light intensity adjustment component 408, thereby adjusting the intensity of the laser.

[0091] The optical input end of beam splitter 3 is connected to the output end of optical intensity controller 4. Several optical output ends of beam splitter 3 are connected to each coupler 5. Beam splitter 3 splits the beam into multiple paths. Each laser beam is emitted from a polarization-maintaining fiber bundle and transmitted to each coupler 5 for beam collimation. After passing through a polarization combination prism, it is transformed into collimated circularly polarized light of a specific spot size and transmitted to atomic magnetometer 6. It is incident on the sensitive meter head of atomic magnetometer and absorbed by the alkali metal gas cell.

[0092] The laser light intensity signal generated after absorption is converted into an electrical signal by a photodetector. The electrical signal output by the photodetector is acquired by the data acquisition module 8 and sent to the main controller 1 for processing and display. The main controller 1 judges the value of the photocurrent. If it is within the usage range, no adjustment is made. If it is outside the usage range, the main controller 1 sends a pulse signal to the light intensity controller 4. When the driver 401 receives a pulse signal, it drives the rotating shaft 4081 to rotate by a corresponding angle in the set direction and checks whether the value of the photocurrent is within the set range. This cycle continues until the magnitude of the photocurrent meets the usage requirements.

[0093] Optionally, in some embodiments, the main controller 1 can also perform a power-on self-test, that is, when the atomic magnetometer system is powered on, the main controller 1 controls the light intensity controller 4 to automatically adjust the light intensity to a suitable threshold range, so as to provide the sensor with the most suitable light intensity.

[0094] Optionally, in some embodiments, the main controller 1 and / or the light intensity controller 4 are provided with a remote control interface to facilitate engineers to perform remote debugging, confirm whether the fault is related to the light intensity controller 4, and thus solve the problem remotely.

[0095] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An optical intensity controller, characterized by, The application relates to a light intensity controller (4) comprising: a housing (407) provided with a light beam channel, and an incident port, an emission port and a light intensity adjusting port communicating with the light beam channel; a light intensity adjusting member (408) arranged at the light intensity adjusting port and comprising a rotating shaft (4081) and a first light blocking piece (4082), the rotating shaft (4081) being perpendicular to the light beam channel and being staggered with the light beam passing through the light beam channel, and the first light blocking piece (4082) being arranged on the rotating shaft (4081) and used for shielding the light beam; a driver (401) arranged on the housing (407) and drivingly connected with the rotating shaft (4081) and used for driving the rotating shaft (4081) to rotate; wherein the rotating shaft (4081) has a first angle interval, in the first angle interval, the first light blocking piece (4082) shields the light beam, and a shielding area of the first light blocking piece (4082) is linearly related to a rotation angle of the rotating shaft (4081); the first light blocking piece (4082) comprises a light shielding surface, and the light shielding surface is a cylindrical surface parallel to the rotating shaft (4081); the light shielding surface comprises a directrix and a director, the directrix is parallel to the rotating shaft (4081), a length of the directrix is M, a spot diameter of the light beam is D, and the directrix satisfies M>D; The said normal line is perpendicular to the said rotating shaft (4081), the distance from any point on the said normal line to the axis of the said rotating shaft is N, the distance from the optical axis of the said light beam to the axis is H, and the said normal line satisfies , .

2. The optical intensity controller of claim 1, wherein, a range of the first angle interval is greater than or equal to 50 degrees.

3. The optical intensity controller of claim 1, wherein, the driver (401) comprises a stepping motor, and in the first angle interval, the shielding area of the first light blocking piece (4082) is linearly related to a pulse amount of the stepping motor.

4. The optical intensity controller of claim 3, wherein, a plurality of speed reduction modules (402) are further arranged, the speed reduction modules (402) are detachably connected between the driver (401) and the rotating shaft (4081), and a connection number of the speed reduction modules (402) is adjustable.

5. The optical intensity controller of claim 1, wherein, the light intensity adjusting member (408) further comprises a second light blocking piece (4083), the second light blocking piece (4083) is arranged on the rotating shaft (4081) and is at an angle with the first light blocking piece (4082), and the second light blocking piece (4083) is provided with a light diaphragm hole for transmitting light.

6. The optical intensity controller of claim 1, wherein, a first collimator (409), a second collimator (411) and a polarization polarizer (410) are further arranged, the first collimator (409) and the second collimator (411) are arranged on the housing (407) and are respectively aligned with the incident port and the emission port, the polarization polarizer (410) is arranged in the light beam channel and is integrated on an end surface of the first collimator (409).

7. An atomic magnetometer system characterized by, The application relates to a light intensity controller (4) comprising: a laser (2); the light intensity controller (4) according to any one of claims 1 to 6 is arranged downstream of the laser (2); a plurality of atomic magnetometers (6) are arranged downstream of the light intensity controller (4).

8. The atomic magnetometer system of claim 7, wherein, The plurality of atomic magnetometers (6) are further provided with a beam splitter (3) arranged between the light intensity controller (4) and the atomic magnetometers (6) and used for making the emission light of the light intensity controller (4) incident on each of the atomic magnetometers (6).

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