Magnetic sub-space imaging scanning device and method based on magneto-optical kerr effect

Abstract

The application relates to the technical field of magnetism measuring instruments, in particular to a magnetic sub-space imaging scanning device and method based on the magneto-optical Kerr effect. The device comprises a transmitting assembly, a scanning assembly and an imaging assembly. The transmitting assembly comprises a laser, a beam expander, a beam splitter, a mirror, a first half-wave plate, a polarization beam splitting cube, a calcite polarizer, a first dichroic mirror, an objective lens, an LED light emitting component, a convex lens and an achromatic doublet lens, so as to focus an incident light beam on a to-be-measured object. The scanning assembly comprises a second dichroic mirror, a second half-wave plate, a mirror, a beam splitting prism, a right-angle reflecting prism, an achromatic doublet lens, a photoelectric balance detector, a lock-in amplifier, a magnetic field applying component and a piezoelectric displacement stage, so as to scan the to-be-measured object. The imaging assembly comprises a convex lens, a CMOS camera and a data processing component, so as to generate a topographic image and a spin wave image. The application can perform high spatial resolution, high magnetic sensitivity and wide frequency band spatial imaging measurement on spin waves and magnetic sub-frequency combs.

Description

Technical Field

[0001] This application relates to the field of magnetic measurement instrument technology, and in particular to a magnetic subspace imaging scanning device and method based on the magneto-optical Kerr effect. Background Technology

[0002] Among related technologies, magnetic particle spatial resolution imaging is key to the study of magnetic particles or spin waves in magnetic materials. Magneto-optical Kerr effect (MOKE) microscopy, as an important magnetic microscopic imaging technique, is widely used in magnetic materials research and is generally divided into poloidal Kerr effect imaging, longitudinal Kerr effect imaging, and transverse Kerr effect imaging.

[0003] However, MOKE microscopy, a related technology, has limited detection sensitivity and lacks components for exciting and measuring dynamic magnetic moments. Therefore, MOKE microscopy is more suitable for spatial imaging of static magnetic moments and not for the study of magnetization dynamics, especially for spatial imaging of propagating magneton modes of nanoscale magnetic structures. It cannot meet the requirements for spatial imaging of magneton at the micro-nano scale, hindering the research on magneton detection and novel magneton devices in the GHz-THz (gigahertz-terahertz) frequency range with nanoscale spatial resolution. This issue urgently needs to be addressed. Summary of the Invention

[0004] This application provides a magnetic space imaging scanning device and method based on the magneto-optical Kerr effect to solve the problems that magnetic microscopy imaging technology in related technologies cannot meet the requirements for wave characteristics research and spatial imaging of propagating magnetic modes of nanoscale magnetic structures, thus hindering the research on nanoscale spatial resolution and magnetic detection and novel magnetic devices in the GHz frequency range.

[0005] The first aspect of this application provides a magneto-optical Kerr effect-based magnetic space imaging scanning device, comprising: an emission assembly including a laser, a beam expander, a first beam splitter, a first reflector, a second reflector, a third reflector, a first half-wave plate, a polarizing beam splitter cube, a fourth reflector, a calcite polarizer, a first dichroic mirror, an objective lens, an LED light emitting component, a first convex lens, a second convex lens, a twelfth reflector, and a first achromatic cemented doublet lens, for focusing the incident light beam onto the object to be measured; and a scanning assembly including a second dichroic mirror, a second half-wave plate, and a second half-wave plate. The system comprises a sixth reflecting mirror, a seventh reflecting mirror, a beam splitter prism, a first right-angle reflecting prism, a second achromatic cemented doublet lens, a third achromatic cemented doublet lens, an eighth reflecting mirror, a ninth reflecting mirror, a tenth reflecting mirror, an eleventh reflecting mirror, a second right-angle reflecting prism, a photoelectric balance detector, a lock-in amplifier, a magnetic field application component, and a piezoelectric displacement stage, used to scan and focus the incident beam onto the object under test to obtain scan data; and an imaging component, comprising a third convex lens, a CMOS camera, and a data processing component, used to generate a morphological image and a spin wave image of the object under test based on the scan data.

[0006] Optionally, in one embodiment of this application, it further includes: a beam expander for expanding and collimating the femtosecond laser to obtain an expanded and collimated femtosecond laser, wherein the femtosecond laser is emitted by the laser; a first beam splitter, a first reflector, a second reflector, a third reflector, and a first half-wave plate for propagating the expanded and collimated femtosecond laser; and a polarization beam splitter cube for separating polarized light from the expanded and collimated femtosecond laser and propagating the polarized light sequentially to the fourth reflector, the calcite polarizer, and the first dichroic mirror.

[0007] Optionally, in one embodiment of this application, the incident beam is coaxial polarized light and LED light, wherein the LED light is emitted by the LED light emitting component.

[0008] Optionally, in one embodiment of this application, it further includes: a second beam splitter for receiving polarized light propagated by the first dichroic mirror and aligning it with the LED beam to obtain the incident beam; and a fifth reflecting mirror for receiving the incident beam and propagating it to the objective lens to focus the incident beam onto the object under test and to propagate the reflected beam from the object under test back to the second beam splitter.

[0009] Optionally, in one embodiment of this application, the method further includes: the surfaces of the first dichroic mirror and the second dichroic mirror are coated with a dichroic beam splitter to achieve selective transmission and reflection of the femtosecond laser and the LED light; the photodiode of the photoelectric balance detector is symmetrically connected to the differential input terminal of the lock-in amplifier, and the reference frequency of the lock-in amplifier is synchronized with the excitation demodulation frequency of the magnetic field application component.

[0010] Optionally, in one embodiment of this application, the first achromatic cemented doublet, the second achromatic cemented doublet, and the third achromatic cemented doublet are an infinite conjugate ratio lens group, and the second achromatic cemented doublet and the third achromatic cemented doublet are symmetrical.

[0011] A second aspect of this application provides a magneto-optical Kerr effect-based magnetic subspace imaging scanning method, comprising the following steps: obtaining an incident beam based on femtosecond laser and LED light, and focusing the incident beam onto the surface of an object to be tested, so as to generate a reflected beam of the beam using the surface of the object to be tested; obtaining initial scanning data of the object to be tested based on the reflected LED light and the reflected femtosecond laser in the reflected beam, and optimizing the initial scanning data according to the target scanning area to obtain complete scanning data; and generating a morphological image and a spin wave image of the object to be tested based on the scanning data.

[0012] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the magneto-optical Kerr effect-based magnetic subspace imaging scanning method as described in the above embodiments.

[0013] A fourth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described magneto-optical Kerr effect-based magnetic subspace imaging scanning method.

[0014] A fifth aspect of this application provides a computer program product, including a computer program that, when executed, is used to implement the above-described magneto-optical Kerr effect-based magnetic subspace imaging scanning method.

[0015] The embodiments of this application can combine femtosecond laser and LED light to obtain an incident beam, and achieve microscale spot focusing on the test object. Then, the beam reflected from the surface of the test object and the balance detector, lock-in amplifier, etc. are used to realize two-dimensional scanning of the object, and the morphological image data of the test object is generated with the help of a CMOS camera. This technology, through a precisely optimized optical path system and a high numerical aperture objective lens, elevates spatial resolution to the nanoscale, enabling the characterization of the spatial distribution characteristics of submicron wavelength spin waves and magnetic frequency combs in nanoscale magnetic structures. This allows for high spatial resolution and high sensitivity magnetic imaging, providing crucial experimental tools for studying the magnetization dynamics of nanoscale magnetic materials. Furthermore, the optimized magneto-optical signal detection system integrates balanced detection and lock-in amplification techniques, significantly improving the sensitivity and signal-to-noise ratio of weak magnetic signal detection. This achieves efficient capture of weak magneto-optical Kerr signals, ensuring high-resolution imaging quality, and is particularly suitable for precise measurement of weak magnetic signals. In addition, the integrated automated data acquisition and control system significantly simplifies experimental procedures and improves efficiency. Researchers can easily complete a series of operations through a user-friendly computer software interface, exhibiting high operability and practicality while maintaining high measurement efficiency and low cost. Therefore, this application addresses the limitations of existing magnetic microscopy imaging techniques in meeting the wave characteristics and spatial imaging requirements of propagating magnetic modes in nanoscale magnetic structures, hindering research on nanoscale spatial resolution and GHz-range magnetic detection and novel magnetic devices.

[0016] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0017] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0018] Figure 1 This is a schematic diagram of a magnetic subspace imaging scanning device based on the magneto-optical Kerr effect according to an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of the structure of a magnetic subspace imaging scanning system based on the magneto-optical Kerr effect according to an embodiment of this application;

[0020] Figure 3 This is a schematic diagram of the focused light spot observed by a camera according to an embodiment of this application;

[0021] Figure 4 This is a schematic diagram illustrating the evolution of spin wave intensity with frequency at a specific location according to an embodiment of this application.

[0022] Figure 5 This is a two-dimensional imaging diagram of the spatial propagation of spin waves of different frequencies according to an embodiment of this application, and a schematic diagram of the corresponding spin wave dispersion relationship.

[0023] Figure 6 This is a schematic diagram of the spatial propagation of spin waves at different frequencies according to an embodiment of this application;

[0024] Figure 7 This is a flowchart of a magnetic subspace imaging scanning method based on the magneto-optical Kerr effect provided in an embodiment of this application;

[0025] Figure 8 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application.

[0026] Figure label:

[0027] 10-Magnetic subspace imaging scanning device based on magneto-optical Kerr effect; 100-Emitting component, 200-Scanning component and 300-Imaging component; 801-Memory, 802-Processor and 803-Communication interface. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0029] The following description, with reference to the accompanying drawings, describes a magnetic subspace imaging scanning method and apparatus based on the magneto-optical Kerr effect according to embodiments of this application. Addressing the limitations of existing MOKE imaging technology mentioned in the background section, which cannot meet the requirements for micro- and nano-scale magnetic subspace imaging, this application provides a magnetic subspace imaging scanning apparatus based on the magneto-optical Kerr effect.

[0030] Specifically, Figure 1 This is a schematic diagram of the structure of a magnetic subspace imaging scanning device based on the magneto-optical Kerr effect provided in an embodiment of this application.

[0031] The emitting assembly 100 includes a laser, a beam expander, a first beam splitter, a first reflector, a second reflector, a third reflector, a first half-wave plate, a polarizing beam splitter cube, a fourth reflector, a calcite polarizer, a first dichroic mirror, an objective lens, an LED light emitting component, a first convex lens, a second convex lens, a twelfth reflector, and a first achromatic cemented doublet lens, to focus the incident light beam onto the object to be tested. The incident light beam consists of coaxial polarized light and LED light, with the LED light emitted by the LED light emitting component.

[0032] Those skilled in the art will understand that in magnetic space imaging, in order to facilitate precise control and modulation of the beam, a series of optical components are used when focusing the incident beam onto the object under test to meet the imaging requirements of the imaging system.

[0033] In some embodiments, this application may refer to various optical components used when focusing an incident beam onto an object under test as the emission assembly 100, including but not limited to a laser, a beam expander, a first beam splitter, a first reflector, a second reflector, a third reflector, a first half-wave plate, a polarizing beam splitter cube, a fourth reflector, a calcite polarizer, a first dichroic mirror, an objective lens, an LED light emitting component, a first convex lens, a second convex lens, a twelfth reflector, and a first achromatic cemented doublet lens.

[0034] like Figure 1 As shown, the femtosecond laser emitted by the laser passes sequentially through a beam expander, a first beam splitter, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, and a first half-wave plate before propagating to a polarization beam splitter cube. The polarized light is separated by the polarization beam splitter cube. This polarized light then passes through a fourth reflecting mirror, a calcite polarizer, a first dichroic mirror, etc., before propagating to the objective lens. Finally, it is aligned with the LED beam emitted by the LED light emitting component. The aligned beam is referred to as the incident beam in this embodiment of the application. The incident beam can be focused onto the surface of the object to be tested.

[0035] In this embodiment, the laser may be, but is not limited to, a 515 nm laser. This laser can emit a light source with high brightness, good monochromaticity, and high stability that meets imaging requirements, providing a high-quality ultrashort pulse light source for the entire optical detection system and helping to improve the visibility of optical signals related to magnetons.

[0036] As a crucial component of the magnetic space imaging system, the objective lens focuses the incident light beam, enabling a clear image of the micro- and nano-structures on the object under test to be formed by a CMOS camera. High numerical aperture (NA) objectives can collect more light, thereby improving the brightness and resolution of the image. Therefore, in this embodiment, a high numerical aperture objective lens with NA = 0.6 can be used, but is not limited to, placing it at the end of the incident light beam's optical path to focus the femtosecond laser onto the surface of the object under test and collect the femtosecond laser reflected from the object. This facilitates real-time monitoring of the object's scanning and effective detection of weak magnetic signals.

[0037] In the imaging optical path, LED light emitted by a 625nm LED light emitting component can be used, but is not limited to. A collimating lens in the optical path ensures the collimation and uniformity of the LED beam, allowing the LED light to pass perpendicularly through the objective lens onto the surface of the object under test, thus enabling observation of the overall morphology of the object. Combined with a femtosecond laser, spatial imaging of spin waves within the object under test can be achieved.

[0038] The LED beam sequentially passes through a first convex lens, a second convex lens, a twelfth reflecting mirror, and a first achromatic cemented doublet lens. After being reflected by a first dichroic mirror, it combines with the polarized light separated from the femtosecond laser beam and is then focused onto the surface of the object under test. Both the first and second convex lenses can be biconvex lenses with a focal length between 40-60 mm to control the focusing of the LED beam, ensuring that the incident beam is focused onto the surface of the object under test.

[0039] The optical components, including the beam expander, first beam splitter, first reflecting mirror, second reflecting mirror, third reflecting mirror, first half-wave plate, polarizing beam splitter cube, fourth reflecting mirror, calcite polarizer, and first dichroic mirror, will be further explained in the following embodiments.

[0040] Optionally, in one embodiment of this application, a beam expander is used to expand and collimate the femtosecond laser beam to obtain the expanded and collimated femtosecond laser beam, wherein the femtosecond laser beam is emitted by a laser; a first beam splitter, a first reflecting mirror, a second reflecting mirror, a third reflecting mirror, and a first half-wave plate are used to propagate the expanded and collimated femtosecond laser beam; a polarization beam splitter cube is used to separate polarized light from the expanded and collimated femtosecond laser beam and propagate the polarized light sequentially to a fourth reflecting mirror, a calcite polarizer, and a first dichroic mirror.

[0041] In practical application, the beam expander in this application can be, but is not limited to, mounted on the laser. The beam expander effectively expands and collimates the femtosecond laser beam, increasing its diameter and cross-sectional area, resulting in a 5x magnified femtosecond laser beam after expansion, collimation, and achromatic correction. This allows for better control of the expanded femtosecond laser beam. To minimize the impact of the value, maintain the parallelism and stability of the femtosecond laser during propagation, reduce the divergence of the femtosecond laser during propagation, improve beam quality, and ensure that the output femtosecond laser beam mode is excellent, so as to ensure that the femtosecond laser beam can be effectively shaped, collimated and focused, thereby improving the resolution and uniformity of imaging.

[0042] After obtaining the expanded and collimated femtosecond laser, the embodiments of this application can then propagate it through a first beam splitter, a first reflector, a second reflector, a third reflector, and a first half-wave plate.

[0043] In this embodiment, the front surface of the first beam-splitting mirror can be coated with a beam-splitting film for a 45° incident angle, and the rear surface can be coated with an anti-reflection film, achieving a 50:50 beam splitting ratio. This allows the laser beam (femtosecond laser) to be split into two or more beams and distributed to different optical paths according to the needs of the imaging system. In this embodiment, the expanded and collimated femtosecond laser can be split into two mutually perpendicular beams with a 50:50 beam splitting ratio, which can be used to detect magneto-optical Kerr signals at room temperature and low temperature, respectively.

[0044] The first, second, third, and fourth reflecting mirrors are all coated with a high-reflectivity dielectric film, achieving a reflectivity of 90% or higher, and up to 99%, when incident at an angle range of 0-45°. By utilizing these reflecting mirrors and their appropriate position and angle arrangement, the femtosecond laser, LED light, the incident beam resulting from the merging of the polarized light separated from the femtosecond laser and the LED light, and the reflected beam can be directed according to the direction required by the embodiments of this application, ensuring that these beams can be accurately incident and reflected. This helps optimize the overall light path layout, making the instrument more compact and flexible.

[0045] Furthermore, considering that in magnetic space imaging, it is generally necessary to control the polarization direction of light (the direction of vibration of the light vector in the beam), this embodiment can employ a first half-wave plate to change the polarization direction of light, thereby meeting the polarization state requirements of other optical elements. The half-wave plate in this embodiment can be, but is not limited to, a zero-order quartz half-wave plate, composed of two wave plates stacked together. The fast axis of one wave plate should be aligned with the slow axis of the other wave plate to achieve zero-order performance and reduce dependence on temperature and wavelength.

[0046] Furthermore, to improve imaging contrast and resolution, embodiments of this application can also employ a polarization beam splitter to separate light of different polarization states. This involves splitting the femtosecond laser into two mutually perpendicular polarized beams according to their polarization direction, obtaining the polarized light required in this embodiment. Specifically, the dielectric beam splitter used in this embodiment reflects s-polarized light and transmits p-polarized light, with a polarization extinction ratio TP:TS greater than 3000:1. This means the ratio of the transmittance of the polarization beam splitter to that of the p-polarized light is greater than 3000:1, thereby maximizing the purity of the separated p-polarized light.

[0047] Additionally, in this embodiment, the first half-wave plate can be disposed in the transmission optical path of the polarization beam splitter cube, thereby precisely adjusting the polarization direction of the incident femtosecond laser and optimizing the polarization state of the incident light to obtain the best magneto-optical Kerr signal intensity.

[0048] After propagating to the fourth reflecting mirror, the polarized light can then propagate to the calcite polarizer. In this embodiment, the calcite polarizer can be used to convert the mixed polarized light in the laser beam into light with a single polarization direction, thereby providing a stable polarized light source for subsequent optical measurements and imaging. Specifically, the calcite polarizer in this embodiment incorporates a prism, which, through an extinction ratio of 10000:1, allows the o-light to scatter and the e-light to directly pass through the polarizer to generate a polarized output, thus producing a larger and more symmetrical field of view, which helps improve the detection accuracy and analysis precision of the magneto-optical signal.

[0049] Furthermore, the embodiments of this application can also take advantage of the wavelength-selective reflection and transmission characteristics of the dichroic mirror, that is, it has high transmittance when the wavelength is less than the cutoff wavelength and high reflectance when the wavelength is greater than the cutoff wavelength. The first dichroic mirror and the cutoff wavelength can be used to distinguish the transmission band and the reflection band. By transmitting the detection incident light with a smaller transmission wavelength and reflecting the LED light with a larger reflection wavelength, the two different wavelengths of light can be confocaled onto the surface of the object to be tested.

[0050] Furthermore, in this embodiment, after the polarization beam splitting cube, a first variable aperture and a second variable aperture with a maximum aperture of 12 mm can be set to adjust the beam diameter. That is, in this embodiment, after optical drift occurs in the femtosecond laser beam, the femtosecond laser can be reset and adjusted by adjusting the fourth and fifth reflecting mirrors, using the first and second variable apertures as a reference, ultimately making the polarized light separated from the femtosecond laser coaxial with the LED light.

[0051] For example, a 515 nm femtosecond laser emits a femtosecond laser beam, which passes sequentially through a beam expander, a first beam splitter, a first reflecting mirror, a second reflecting mirror, and a third reflecting mirror. Then, it passes through a first half-wave plate and a polarizing beam splitter cube to separate the s-beam and p-beam, resulting in p-polarized light. The p-polarized light then passes sequentially through a fourth reflecting mirror and a calcite polarizer. Finally, it passes through a first dichroic mirror and a second beam splitter, and is combined with 625 nm LED light to obtain the incident beam. This incident beam is then focused onto the surface of the object being tested by a fifth reflecting mirror and an objective lens.

[0052] Specifically, in this embodiment, a beam expander can be set in the emission path of a 515 nm femtosecond laser to expand and collimate the femtosecond laser beam, resulting in an expanded and collimated femtosecond laser. Next, a first beam splitter can split the expanded and collimated femtosecond laser beam into two paths with a splitting ratio of 50:50. After passing through three high-reflectivity mirrors (first, second, and third), the beam's polarization state is adjusted by a first half-wave plate, and the extinction ratio of the analyzer is optimized, thereby further improving the detection sensitivity of the magneto-optical Kerr signal. Then, by using a polarization beam splitter cube and a first variable aperture, the polarization state and beam diameter of the incident femtosecond laser can be adjusted to separate the s-beam and p-beam, obtaining p-polarized light. Furthermore, a calcite polarizer is set after a fourth mirror, and the p-polarized light is then combined with the LED light by a first dichroic mirror and a second beam splitter. Finally, the light is focused onto the surface of the object under test by a second variable aperture, a fifth mirror, and an objective lens.

[0053] The magnification and position of the objective lens can be adjusted by professionals in the field according to the actual situation to achieve a wide and clear field of view.

[0054] The second beam splitter and the fifth reflecting mirror in the embodiments of this application will be explained next.

[0055] Optionally, in one embodiment of this application, it further includes: a second beam splitter for receiving polarized light propagated by the first dichroic mirror and aligning it with the LED light axis to obtain an incident beam; and a fifth reflector for receiving the incident beam and propagating it to the objective lens to focus the incident beam onto the object under test and to propagate the reflected beam from the object under test back to the second beam splitter.

[0056] Based on the descriptions of other embodiments, it is understood that during the propagation of the femtosecond laser, after the polarized light (such as p-polarized light) separated from the femtosecond laser is superimposed on the LED light by the first dichroic mirror, it will be focused onto the surface of the object to be tested after passing through the second beam splitter, the second variable aperture, the fifth reflecting mirror and the objective lens.

[0057] For example, after the p-polarized light propagates through the first dichroic mirror to the second beam splitter, the second beam splitter transmits the polarized light separated from the incident femtosecond laser and the LED light, and makes the two coaxially combine to obtain the incident beam. Then, the incident beam propagates sequentially to the second variable aperture, the fifth reflecting mirror and the objective lens, thereby focusing the incident beam onto the surface of the object to be tested.

[0058] The reflected light beam, after passing through the surface of the object under test, returns to the fifth mirror. The fifth mirror then transmits the reflected light beam to the second beam splitter, which then reflects the femtosecond laser and LED light passing through the surface of the object under test to perform a spin wave imaging scanning process.

[0059] The imaging and scanning process of the object under test in the embodiments of this application will be explained below.

[0060] The scanning assembly 200 includes a second dichroic mirror, a second half-wave plate, a sixth reflecting mirror, a seventh reflecting mirror, a beam splitter prism, a first right-angle reflecting prism, a second achromatic cemented doublet, a third achromatic cemented doublet, an eighth reflecting mirror, a ninth reflecting mirror, a tenth reflecting mirror, an eleventh reflecting mirror, a second right-angle reflecting prism, a photoelectric balance detector, a lock-in amplifier, a magnetic field application component, and a piezoelectric displacement stage. It scans the object under test after focusing the incident beam to obtain scanning data. The first, second, and third achromatic cemented doublets are an infinite conjugate ratio lens group, and the second and third achromatic cemented doublets are symmetrical.

[0061] As one possible implementation, the scanning component 200 in this application embodiment can realize the imaging scanning process of the object under test. The scanning component 200 in this application embodiment includes, but is not limited to, a second dichroic mirror, a second half-wave plate, a sixth reflecting mirror, a seventh reflecting mirror, a beam splitter prism, a first right-angle reflecting prism, a second achromatic cemented doublet lens, a third achromatic cemented doublet lens, an eighth reflecting mirror, a ninth reflecting mirror, a tenth reflecting mirror, a second right-angle reflecting prism, a photoelectric balance detector, a lock-in amplifier, a magnetic field application component, and a piezoelectric displacement stage. Through the cooperation of these components, the scanning data required for imaging the object under test can be obtained in this application embodiment.

[0062] After the reflected beam propagates through the fifth reflecting mirror to the second beam splitter, the second beam splitter propagates it to the second dichroic mirror. The second dichroic mirror separates the femtosecond laser and LED light in the reflected beam. The second dichroic mirror functions similarly to the first dichroic mirror, distinguishing between the transmission and reflection bands based on the cutoff wavelength. It detects the outgoing light (reflected femtosecond laser light passing through the surface of the object under test) with a shorter transmission wavelength, ensuring the light signal reaches the photoelectric balance detector and is received. It also reflects the LED light (reflected LED light passing through the surface of the object under test), facilitating the visualization of the object's surface through the outgoing light signal.

[0063] The separated emitted light beam passes through the second half-wave plate, the sixth reflector, the seventh reflector, and the beam splitter prism. It is then split into two parallel beams by the first right-angle reflecting prism. These two beams pass through the symmetrical eighth and ninth reflectors, the symmetrical second and third achromatic doublet lenses, and the symmetrical tenth and eleventh reflectors, respectively, before propagating to the second right-angle reflecting prism. The beams then enter the two ports of the photoelectric balance detector through the second right-angle reflecting prism. With the help of a lock-in amplifier and a computer, the magneto-optical Kerr signal of the object under test can be obtained.

[0064] In this embodiment, after the incident light beam is focused onto the object under test, the light interacts with the object through a magneto-optical effect and returns along the same path. This application's embodiment can utilize the magneto-optical effect to measure the spin wave of magnetic materials. The magnetization state and spin wave propagation characteristics of the object under test are controlled by an external magnetic field generated by an electromagnet. The position of the object under test is moved using a piezoelectric displacement stage to complete the spatial imaging of the spin wave. The spin wave can be excited by a microwave antenna on the object under test.

[0065] The electromagnet in the magnetic field application device provides an adjustable static magnetic field, while the voltage generator in the device is used to precisely adjust the position of the test object, achieving accurate control of the scanning area. By combining the electromagnetic field and the voltage generator with the special microstructure on the surface of the test object, a radio frequency magnetic field can be generated on the surface of the test object, exciting the spin wave in the magnetic test object. The surface of the test object will then generate reflected light beams, including the detection output beam and the imaging output beam.

[0066] The second half-wave plate is located in the optical path of the detected outgoing light after reflection. It can adjust the polarization state of the detected outgoing light, optimize the extinction ratio of the analyzer, and further improve the detection sensitivity of the magneto-optical Kerr signal.

[0067] The fifth, sixth, seventh, eighth, ninth, tenth, eleventh, and twelfth reflectors are also high-reflectivity reflectors. When incident at an angle range of 0-45°, their reflectivity can reach 90% or more, with a maximum of 99%. Their function is to direct the propagation of the light beam, optimize the optical path layout, and ensure that the light beam can be accurately incident and reflected.

[0068] In other embodiments, the first achromatic cemented doublet lens and the second and third achromatic cemented doublet lenses in this application embodiment form an infinite conjugate ratio lens group. That is, the first, second, and third achromatic cemented doublet lenses are all computer-optimized, have an infinite conjugate ratio, can control chromatic aberration, and produce diffraction-limited light spots; and are all coated with a 400-700 nm anti-reflection film to optimize the beam achromaticity and reduce the impact of chromatic aberration on image quality; and the second and third achromatic cemented doublet lenses are symmetrically arranged.

[0069] Furthermore, the beam splitter in the embodiments of this application may be, but is not limited to, a Wollaston prism. The Wollaston prism uses a calcite substrate coated with an antireflection film, which can separate unpolarized light into two beams of orthogonally polarized light. The beam splitting angle may be, but is not limited to, set to 20°. Combined with the 350-700 nm antireflection film coated on the calcite substrate, the transmittance of the femtosecond laser can be increased.

[0070] Furthermore, in this embodiment, a coating can be deposited on the right-angled sides of the first and second right-angled reflecting prisms, thereby enabling the right-angled sides of the coating to reflect the light beam, ensuring that the light beam is reflected at a precise angle and optimizing the optical path layout. Specifically, the first right-angled reflecting prism primarily splits the detected outgoing light beam into two parallel beams, while the second right-angled reflecting prism primarily reflects the two beams in parallel to the two input ports of the photoelectric balance detector.

[0071] Next, the photoelectric balance detector can acquire the differential signal of the reflected beam, and the lock-in amplifier extracts the signal and synchronously controls the piezoelectric displacement stage to perform two-dimensional scanning. The first dichroic mirror, the second dichroic mirror, the photoelectric balance detector, and the lock-in amplifier in the embodiments of this application will be further explained below.

[0072] Optionally, in one embodiment of this application, the surfaces of the first and second dichroic mirrors are coated with dichroic beam splitting films to achieve selective transmission and reflection of femtosecond laser and LED light; the photodiodes of the photoelectric balance detector are symmetrically connected to the differential input terminal of the lock-in amplifier, and the reference frequency of the lock-in amplifier is synchronized with the frequency of the external clock source, which can be, but is not limited to, set to 10 MHz.

[0073] Based on the descriptions of other embodiments, it is understood that the embodiments of this application can utilize a first dichroic mirror to transmit a femtosecond laser with a smaller wavelength (e.g., 515 nm) and its separated polarized light, and reflect LED light with a larger wavelength (e.g., 625 nm), so that two light sources of different wavelengths are confocalized onto the surface of the object to be tested; and utilize a second dichroic mirror to transmit and reflect the reflected femtosecond laser (separated polarized light), so that its light signal reaches the photoelectric balance detector and is received, and further reflects the LED light into the camera, thereby realizing the visualization of the surface of the object to be tested.

[0074] The first and second dichroic mirrors are coated with dichroic films and antireflective films, respectively, so as to distinguish the transmission band and the reflection band by combining the cutoff wavelength. This allows the transmission of the femtosecond laser with a smaller transmission wavelength and its separated polarized light, and the reflection of the LED light with a larger reflection wavelength, so that the two different wavelengths of light are confocaled onto the surface of the object under test, or propagated to the photoelectric balance detector and the camera respectively, thereby improving the signal-to-noise ratio of the image.

[0075] The photoelectric balanced detector configured in this embodiment can detect changes in the intensity of the reflected light beam and convert the optical signal into an electrical signal. Specifically, the photoelectric balanced detector in this embodiment includes, but is not limited to, a balanced detector module with two matched photodiodes, possessing high bandwidth and low noise characteristics. These two output ports can be symmetrically connected to the differential input ports of a lock-in amplifier to ensure effective detection of high-frequency magneto-optical Kerr signals and low-noise signal acquisition, thus achieving a balanced detection mode.

[0076] A lock-in amplifier can extract weak magneto-optical Kerr signals and improve the signal-to-noise ratio. Furthermore, the signal output port of the lock-in amplifier in this embodiment can be connected to a data acquisition and control system, facilitating the transmission of the demodulated magneto-optical Kerr signal data to a computer for further processing and analysis. It should also be noted that the external reference frequency of the lock-in amplifier and the external reference frequency of the RF signal source in this embodiment are synchronized with an external clock source; the frequency can be, but is not limited to, set to 10 MHz, ensuring that the initial phase of the spin wave remains unchanged during imaging.

[0077] Additionally, the data acquisition and control system can be used to control the entire device, performing signal input, reception, and analysis. Specifically, the data acquisition and control system can directly control the radio frequency signal source to output the required radio frequency signal through the system's control program, exciting the microwave antenna on the test object and generating spin waves in the test object. After the femtosecond laser is focused onto the surface of the test object, it is reflected. The reflected femtosecond laser is received by the photoelectric balance detector through the detection optical path system and amplified and demodulated by the lock-in amplifier.

[0078] The computer can acquire the magneto-optical Kerr signal data output by the lock-in amplifier in real time and store the data on the computer's hard drive.

[0079] The embodiments of this application employ balanced detection technology and lock-in amplification technology for signal processing to improve the detection sensitivity and signal-to-noise ratio of the magneto-optical Kerr signal. Specifically, balanced detection technology effectively suppresses common-mode noise, while lock-in amplification technology can extract weak modulation signals from strong noise backgrounds. This allows the application to sensitively capture and quantize weak magneto-optical Kerr signals, ensuring high-quality, low-noise magneton space images while performing high spatial resolution imaging. This is particularly suitable for the accurate measurement of weak magnetic signals such as spin waves and magneton frequency combs.

[0080] Furthermore, the magneto-optical Kerr effect-based magnetic subspace imaging scanning device in this application embodiment can integrate an automated data acquisition and control system, which allows researchers to conveniently and quickly set experimental parameters, control system operation, acquire, process, and analyze data through a computer software interface. It also helps to realize real-time reconstruction and display of magnetic subspace images, greatly simplifies the experimental operation process, reduces the requirements for the professional skills of operators, improves experimental efficiency, simplifies data processing, and is conducive to the implementation and practical application of this application in the field of magnetonics research.

[0081] Imaging component 300 includes a third convex lens, a CMOS camera, and a data processing unit, used to generate a topographic image and a spin wave image of the object under test based on the scan data.

[0082] In other embodiments, the reflected beam is separated into a detection beam (femtosecond laser) and an imaging beam (LED beam) at the second dichroic mirror. The LED beam then passes through a third convex lens to reach the CMOS camera, thereby realizing a visual imaging of the surface morphology of the object under test, i.e., a morphology image, which provides a reference and assistance for magneto-optical Kerr effect measurement.

[0083] In this embodiment, the third convex lens is mainly combined with the first convex lens and the second convex lens to realize continuous beam waist transformation, optimize optical path transmission, ensure that the incident beam can be effectively focused on the surface of the object to be tested, and that the reflected beam can be received by the CMOS camera and the photoelectric balance detector.

[0084] Furthermore, the CMOS camera in this embodiment is configured as a high-resolution, low-noise CMOS camera, and the pixel size should be smaller than [missing information]. The resolution should be no less than A pixel is capable of capturing an optical image of the surface of an object under test, and is equipped with a data processing component, including but not limited to real-time image acquisition, display and processing functions, thereby realizing a visual imaging of the surface morphology of the object under test.

[0085] Specifically, in this embodiment, the optical path elements and piezoelectric displacement stage can be adjusted according to the imaging signal (emitted light signal) received by the CMOS camera, such as adjusting the position of the reflector, aperture, objective lens and displacement stage, to ensure that the imaging field of view displayed on the computer is wide and clear, the light spot is focused on the appropriate position of the object under test, the magnitude of the radio frequency signal is controlled, the measurement area of ​​the object under test is adjusted, and data is collected in real time to obtain relevant data (images) of the magnetic subspace imaging of the object under test.

[0086] The piezoelectric displacement stage is used to control the movement of the object under test. Specifically, in this embodiment, during image acquisition, the fifth reflecting mirror and objective lens are adjusted to make the reflected light spot coincide with the incident light spot, and the scanning area is set by acquiring the image through a CMOS camera. At this time, the piezoelectric displacement stage can be initialized and positioned. Furthermore, during spatial imaging measurement, the data acquisition and control system can synchronously control the piezoelectric displacement stage to achieve high spatial resolution positional movement for comprehensive two-dimensional scanning. Magneto-optical Kerr signal data at different spatial locations are acquired point-by-point to obtain comprehensive scan data, and the morphological image and spin wave image of the object under test are generated based on the scan data.

[0087] The embodiments of this application can realize high spatial resolution, high magnetic sensitivity, and wide bandwidth spatial imaging measurement of spin waves and magnetic frequency combs, and have the advantages of simple operation, high degree of automation, and high measurement accuracy. They are easy to promote and apply and have broad application prospects.

[0088] The present application will be explained in detail below with reference to a specific embodiment.

[0089] Figure 2 This is a schematic diagram of the structure of a magnetic subspace imaging scanning system based on the magneto-optical Kerr effect according to an embodiment of this application. Figure 2 As shown, the magneto-optical Kerr effect-based magnetic space imaging scanning system includes: 1-515 nm laser; 2-beam expander; 3-first beam splitter; 4-first reflecting mirror; 5-second reflecting mirror; 6-third reflecting mirror; 7-first half-wave plate; 8-polarizing beam splitter cube; 9-first variable aperture; 10-fourth reflecting mirror; 11-calcite polarizer; 12-first dichroic mirror; 13-second beam splitter; 14-second variable aperture; 15-fifth reflecting mirror; 16-objective lens; 17-object under test; 18-magnetic field application device; 19-piezoelectric displacement stage; 20-625 nm LED diode; 21-First convex lens; 22-Second convex lens; 23-Twelfth reflecting mirror; 24-First achromatic cemented doublet lens; 25-Second dichroic mirror; 26-Third convex lens; 27-CMOS camera; 28-Second half-wave plate; 29-Sixth reflecting mirror; 30-Seventh reflecting mirror; 31-Wollaston prism; 32-Eighth reflecting mirror; 33-Ninth reflecting mirror; 34-First right-angle reflecting prism; 35-Second achromatic cemented doublet lens; 36-Third achromatic cemented doublet lens; 37-Tenth reflecting mirror; 38-Eleventh reflecting mirror; 39-Second right-angle reflecting prism; 40-Photoelectric balance detector; 41-Lock-in amplifier.

[0090] Using a 104 nm yttrium iron garnet (YIG) thin film as the test object, the optical photograph after successful focusing of the light spot is shown below. Figure 3 As shown. The specific implementation steps are as follows:

[0091] (1) A 515 nm laser 1 emits a femtosecond laser, which is collimated and expanded by a beam expander 2 to improve the quality of the femtosecond laser. (Value optimization). The polarization state of the incident light is adjusted by the first half-wave plate 7, and the s-polarized light and p-polarized light are separated by the polarization beam splitter 8. The p-polarized light is further purified by the calcite polarizer 11 (extinction ratio >10000:1). The p-polarized light beam is combined with the LED light by the first dichroic mirror 12 and focused onto the surface of the object to be tested 17 by the objective lens 16. The beam of light reflected and combined from the object under test is split by the second beam splitter 13, passes through the second dichroic mirror 25, then through the second half-wave plate 28 and the sixth reflecting mirror 29, and reaches the Wollaston prism 31. The beam is decomposed into o-ray and e-ray, and then split into two parallel beams by the first right-angle reflecting prism 34. After passing through the eighth reflecting mirror 32, the ninth reflecting mirror 33, the second achromatic cemented doublet lens 35, and the third achromatic cemented doublet lens 36, the beam is reflected by the tenth reflecting mirror 37 and the eleventh reflecting mirror 38 to the second right-angle reflecting prism 39, and then reflected into the dual-port photoelectric balance detector 40 to realize differential signal detection.

[0092] (2) The 625 nm LED light emitting component (LED diode) 20 emits LED light, which is collimated by the first convex lens 21 and the second convex lens 22 and coaxially merged with the femtosecond laser at the first dichroic mirror 12. The LED light beam reflected by the object under test is separated by the second dichroic mirror 25 and focused by the third convex lens 26 onto the CMOS camera 27.

[0093] (3) The surface morphology of the object under test is observed in real time through the CMOS camera 27. The pitch angle of the fifth reflecting mirror 15, the height of the objective lens 16, and the position of the piezoelectric displacement stage 19 are adjusted so that the light spot is focused on the preset area of ​​the object under test 17. The preset area can be determined or adjusted by those skilled in the art according to the actual imaging situation and actual imaging needs. This embodiment is only illustrative and does not impose any specific limitations.

[0094] (4) Activate the photoelectric balance detector 40 and the lock-in amplifier 41, set the reference frequency of the lock-in amplifier to the signal modulation frequency, and set the integration time to suppress environmental noise. Apply an external magnetic field to the test object through the magnetic field application device 18, connect the radio frequency signal source to the microwave antenna of the test object through the coaxial line and the radio frequency probe, set the excitation frequency range (e.g., 1-2.1 GHz) and output power, and excite the spin wave in the YIG thin film.

[0095] (5) Set the scanning area (e.g., 60μm × 60μm) in the computer control interface, set the movement step size of the piezoelectric displacement stage 19, and simultaneously start the real-time imaging function of the CMOS camera 27 to monitor the spot position and spot size for real-time positioning and automatic spot focusing. After starting the data acquisition program, magneto-optical Kerr signals of different frequencies and positions can be acquired by changing variables such as excitation frequency and displacement area to complete the magnetospace imaging measurement.

[0096] Figure 4 This is a schematic diagram illustrating the evolution of spin wave intensity with frequency at a specific location according to an embodiment of this application. Figure 4 This application demonstrates that the magneto-optical Kerr effect-based magnetic subspace imaging scanning system has the function of measuring broadband spin waves.

[0097] Figure 5 This is a two-dimensional imaging diagram of the spatial propagation of spin waves of different frequencies according to an embodiment of this application, and a schematic diagram of the corresponding spin wave dispersion relationship. Figure 5 The left figure shows the spatial distribution of YIG spin wave signal intensity at different excitation frequencies, describing the spatial propagation characteristics of spin waves; Figure 5 The right figure is the Fourier transform corresponding to the left figure. Using this method, the dispersion relation of spin waves can be obtained.

[0098] Figure 6 This is a spatial propagation diagram of spin waves at different frequencies according to an embodiment of this application. Figure 6 As shown, it illustrates the spatial propagation spectra of spin waves with frequencies of 1300 MHz, 1400 MHz, and 1500 MHz in a YIG thin film according to embodiments of this application. It demonstrates that the magneton spatial imaging scanning system based on the magneto-optical Kerr effect in embodiments of this application possesses spatial imaging capabilities for spin waves.

[0099] Figure 7 This is a flowchart of a magnetic subspace imaging scanning method based on the magneto-optical Kerr effect according to an embodiment of this application. The scanning method includes the following steps:

[0100] Step S701: Based on femtosecond laser and LED light, an incident beam is obtained and focused onto the surface of the object to be tested, so as to generate a reflected beam of the incident beam using the surface of the object to be tested;

[0101] Step S702: Based on the reflected LED light and reflected femtosecond laser in the reflected beam, the initial scanning data of the object to be tested is obtained, and the initial scanning data is optimized according to the target scanning area to obtain complete scanning data;

[0102] Step S703: Generate the morphological image and spin wave image of the object to be tested based on the scanning data.

[0103] It should be noted that the foregoing explanation of the embodiment of the magnetic subspace imaging scanning device based on the magneto-optical Kerr effect also applies to the magnetic subspace imaging scanning method based on the magneto-optical Kerr effect in this embodiment, and will not be repeated here.

[0104] Figure 8 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include:

[0105] The memory 801, the processor 802, and the computer program stored on the memory 801 and capable of running on the processor 802.

[0106] When the processor 802 executes the program, it implements the magnetic subspace imaging scanning method based on the magneto-optical Kerr effect provided in the above embodiments.

[0107] Furthermore, electronic devices also include:

[0108] Communication interface 803 is used for communication between memory 801 and processor 802.

[0109] The memory 801 is used to store computer programs that can run on the processor 802.

[0110] The memory 801 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0111] If the memory 801, processor 802, and communication interface 803 are implemented independently, then the communication interface 803, memory 801, and processor 802 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized into address buses, data buses, control buses, etc. For ease of representation, Figure 8 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0112] Optionally, in a specific implementation, if the memory 801, processor 802, and communication interface 803 are integrated on a single chip, then the memory 801, processor 802, and communication interface 803 can communicate with each other through an internal interface.

[0113] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described magneto-optical Kerr effect-based magnetic subspace imaging scanning method.

[0114] This application also provides a computer program product, including a computer program that can run computer instructions. When the computer instructions are executed by a processor, they implement the magnetic subspace imaging scanning method based on the magneto-optical Kerr effect provided in this application.

[0115] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0116] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0117] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0118] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0119] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0120] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0121] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0122] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A magnonic spatial imaging scanning device based on the magneto-optical Kerr effect, characterized in that, The application relates to a kind of devices for measuring the spin wave of material, including: Emission component, the emission component includes laser, beam expander, first beam splitter, first mirror, second mirror, third mirror, first half-wave plate, polarization beam splitting cube, fourth mirror, calcite polarizer, first dichroic mirror, objective lens, LED light emitting component, first convex lens, second convex lens, twelfth mirror and first achromatic doublet lens, to focus incident light beam on the measured article, wherein the laser emits femtosecond laser as probe light source; Scan component, the scan component includes second dichroic mirror, second half-wave plate, sixth mirror, seventh mirror, beam splitter prism, first right-angle reflecting prism, second achromatic doublet lens, third achromatic doublet lens, eighth mirror, ninth mirror, tenth mirror, eleventh mirror, second right-angle reflecting prism, photoelectric balance detector, lock-in amplifier, magnetic field applying component, piezoelectric displacement stage, to scan the measured article after focusing the incident light beam, obtain scanning data; Imaging component, the imaging component includes third convex lens, CMOS camera and data processing component, for generating the topographic image and spin wave image of the measured article according to the scanning data; Wherein, the first dichroic mirror and the second dichroic mirror are coated with a two-way light splitting film to complete the selective transmission and reflection of the femtosecond laser and LED light;The photodiode of the photoelectric balance detector is symmetrically connected to the differential input end of the lock-in amplifier, and the external reference frequency of the lock-in amplifier and the external reference frequency of the RF signal source are synchronized; Wherein, the magnetic field applying component is used to apply an external magnetic field to the measured article, and the RF signal source is connected to the microwave antenna on the measured article through a coaxial line and an RF probe to excite the spin wave in the measured article.

2. The magneto-optical Kerr effect based magnetic sub-space imaging scanning device according to claim 1, characterized in that, Also includes: The beam expander is used to expand and collimate the femtosecond laser, and the expanded and collimated femtosecond laser is obtained, wherein the femtosecond laser is emitted by the laser; The first beam splitter, the first mirror, the second mirror, the third mirror and the first half-wave plate are used to propagate the expanded and collimated femtosecond laser. The polarization beam splitting cube is used to separate the polarized light from the expanded and collimated femtosecond laser, and sequentially propagate the polarized light to the fourth mirror, the calcite polarizer and the first dichroic mirror.

3. The magneto-optical Kerr effect based magnetic sub-space imaging scanning apparatus according to claim 2, characterized in that, The incident light beam is coaxial with the polarized light and LED light, wherein the LED light is emitted by the LED light emitting component.

4. The magneto-optical Kerr effect based magnetic sub-space imaging scanning apparatus according to claim 3, characterized in that, Also includes: Second beam splitter, for receiving the polarized light propagated by the first dichroic mirror, and coaxial with the LED light to obtain the incident light beam; Fifth mirror, for receiving the incident light beam and propagating to the objective lens to focus the incident light beam on the measured article, and reversely propagating the reflected light beam of the measured article to the second beam splitter.

5. The magneto-optical Kerr effect based magnetic sub-space imaging scanning apparatus according to claim 1, wherein, The first achromatic doublet lens, the second achromatic doublet lens and the third achromatic doublet lens are infinite conjugate ratio lens groups, and the second achromatic doublet lens and the third achromatic doublet lens are symmetrical.

6. A magnonic spatial imaging scanning method based on magneto-optical Kerr effect, applied to the magnonic spatial imaging scanning device based on magneto-optical Kerr effect in any one of claims 1-5, characterized in that, The method comprises the following steps: The femtosecond laser emitted by the laser is combined with the LED light, focused to the surface of the object to be measured through the objective lens, and the combined light beam is reflected to the two-port photobalanced detector of the object to be measured to focus the LED exit light beam reflected by the object to be measured to the CMOS camera, wherein the photobalanced detector is used to realize differential signal detection. The photobalanced detector and the lock-in amplifier are started, the external reference frequency of the lock-in amplifier and the external reference frequency of the radio frequency signal source are synchronized, an external magnetic field is applied to the object to be measured through the magnetic field application component, the radio frequency signal source is connected to the microwave antenna on the object to be measured through the coaxial line and the radio frequency probe, and the spin wave in the object to be measured is excited. The data acquisition program is started, the magnetic sub-space imaging measurement is completed, the complete scanning data is obtained, and the topographic image and the spin wave image of the object to be measured are generated according to the scanning data.

7. An electronic device, comprising: It comprises: A memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to realize the magnetic sub-space imaging scanning method based on the magneto-optical Kerr effect according to claim 6.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to realize the magnetic sub-space imaging scanning method based on the magneto-optical Kerr effect according to claim 6.

9. A computer program product comprising a computer program, characterized in that, The computer program is executed to realize the magnetic sub-space imaging scanning method based on the magneto-optical Kerr effect according to claim 6.

Images