Method for measuring number of layers of two-dimensional material by utilizing Goos-Hanchen shift

Abstract

The invention discloses a method for measuring the number of layers of a two-dimensional material by utilizing Goos-Haenchen displacement, which comprises the following steps: establishing a Goos-Haenchen displacement theoretical database when a horizontal polarized light beam is reflected on the surfaces of the two-dimensional materials with different layers at different incident angles according to a theoretical relation model of the two-dimensional materials with different layers and the Goos-Haenchen displacement; enabling the horizontal polarization incident light beam to be incident to the surface of the measured two-dimensional material at a certain incident angle; measuring Goos-Hanchen shift generated by the reflected light beam under the condition; sequentially changing the incident angles to obtain a group of Goos-Hanchen shift measurement data under different incident angles; and comparing and analyzing the measured data with theoretical data in a Goos-Hanchen shift theory database to obtain the number of layers of the measured two-dimensional material. Compared with a traditional two-dimensional material layer number measuring method, such as a Raman spectrum method, an atomic force microscopy method and a transmission electron microscope method, the method is easy to operate and high in measuring efficiency, does not damage a sample and has a good application prospect.

Description

Technical Field

[0001] This invention relates to the field of optical detection technology, and more particularly to a method for measuring the number of layers in a two-dimensional material. Background Technology

[0002] With the rapid development of nanotechnology and materials science, two-dimensional materials, due to their unique physical and chemical properties, are widely used in electronic devices, sensors, optoelectronic devices, and other fields. Graphene, transition metal sulfides (TMDs), and other two-dimensional materials have become research hotspots due to their thin-layer structure and excellent properties. Since the number of layers in two-dimensional materials has a significant impact on their performance, how to accurately measure the number of layers in these materials has become a crucial problem that urgently needs to be solved.

[0003] Currently, traditional methods for measuring the number of layers in two-dimensional materials, such as atomic force microscopy (AFM), transmission electron microscopy (TEM), and Raman spectroscopy, can provide relatively accurate layer count information. However, these methods often rely on direct observation of sample surface features or require complex equipment and procedures, and usually have high requirements for sample processing, thus having certain limitations.

[0004] Against this backdrop, Gushanshin displacement ( The Gushansen shift, a surface optical effect, has been proposed as a potential means of measuring the number of layers in two-dimensional materials due to its sensitivity to minute structural changes on the material surface. The Gushansen shift describes the slight displacement of the propagation direction of reflected light relative to the incident light when a light wave is reflected at a medium interface. This displacement is closely related to the structure and properties of the reflecting interface medium (such as thickness and optical constants). When the reflecting interface is a two-dimensional material, the change in the number of layers is a change in the interface structure; however, currently, there is no method to measure the number of layers in two-dimensional materials using the Gushansen shift.

[0005] Patent application number 202211106087.1 discloses a method for determining the number of layers in a two-dimensional material using dark-field optical imaging technology. The method includes: light generated by a light source is obliquely incident on the observed two-dimensional material sample and substrate through the optical path of a dark-field optical imaging technology system, with some scattered light falling within the light collection range of the optical information receiving device of the dark-field optical imaging technology system; the scattered light from the area where the number of layers in the two-dimensional material sample changes is collected and converted into an optical photograph; the brightness value of each pixel in the optical photograph is read, and a position-brightness curve is plotted; the dark-field contrast or relative contrast is calculated; and the number of layers in the two-dimensional material is calculated based on the correlation between the number of layers and the dark-field contrast or relative contrast. The accuracy of the above invention is higher than that of the optical contrast method. However, the above invention requires prior measurement of the number of layers in the sample using other methods, followed by measurement of the dark-field contrast or relative contrast of the sample with each layer number. Then, a quantitative relationship between the number of layers and the dark-field contrast or relative contrast is obtained using a corresponding method (this is an empirical relationship model), which is necessary to measure the number of layers in the material being tested. The accuracy of this measurement method relies heavily on the established empirical model. When measurement conditions or system parameters change, the previous empirical model may become invalid, leading to a significant decrease in measurement accuracy. For example, when factors such as light source aging or sample surface differences cause changes in field contrast or relative contrast, the reliability of the empirical model decreases, resulting in a drop in measurement accuracy. Furthermore, because the quantitative relationship between the number of layers and dark-field contrast or relative contrast differs for different materials, when the material being measured is changed, this method requires repeating the above steps to re-establish the quantitative relationship between the number of layers and dark-field contrast or relative contrast for the new material. This process is tedious and time-consuming. Summary of the Invention

[0006] To address the technical problems of traditional methods relying on complex equipment, cumbersome operation procedures, and stringent requirements for sample processing conditions, which make it difficult to achieve efficient and convenient measurement, this invention proposes a method for measuring the number of layers in two-dimensional materials using the Gusshamsen displacement. Compared with traditional methods for measuring the number of layers in two-dimensional materials, such as Raman spectroscopy, atomic force microscopy, and transmission electron microscopy, this invention is not only simple to operate and highly efficient, but also does not damage the sample, and has good application prospects.

[0007] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0008] A method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement includes the following steps:

[0009] S1. Based on the theoretical relationship model between two-dimensional materials with different numbers of layers and the Gus-Hansen displacement, establish a theoretical database of Gus-Hansen displacement when a horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different numbers of layers.

[0010] S2. A horizontally polarized incident beam is incident on the surface of the two-dimensional material to be measured at a certain incident angle;

[0011] S3. Using the method or apparatus for measuring the Gus-Hans-Hans displacement, obtain the Gus-Hans-Hans displacement produced by the reflected beam under the conditions of step S2.

[0012] S4. Change the incident angle sequentially and repeat step S3 to obtain a set of Gushanshin displacement measurement data under different incident angles.

[0013] S5. Compare and analyze the Gushansen displacement measurement data obtained in step S4 at different incident angles with the theoretical data in the Gushansen displacement theoretical database established in step S1 when the horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different layers, and obtain the number of layers of the two-dimensional material being measured.

[0014] Specifically, the theoretical relationship model between the two-dimensional materials with different numbers of layers and the Gushanshin displacement is as follows:

[0015]

[0016] in:

[0017]

[0018]

[0019]

[0020]

[0021] In the formula, △ GH (N) represents the Gushanshin displacement, δ GH Represents the spatial displacement of Gushanshin, Θ GH This represents the angular displacement of Gushanshin; τ1, Γ1, κ1, and κ2 are all intermediate parameters; z r R represents the propagation distance of the reflected beam. p The Fresnel reflection coefficient r of horizontally polarized light p The modulus of R s The Fresnel reflection coefficient r represents vertically polarized light. s The modulus of φ; p The Fresnel reflection coefficient r of horizontally polarized light p phase, φ s The Fresnel reflection coefficient r represents vertically polarized light. s The phase; Re denotes taking the real part of a complex number, and Im denotes taking the imaginary part of a complex number; z R k represents the Rayleigh length of the incident beam. rThe wavenumber of the reflected beam is represented by N, where N is the number of two-dimensional material layers and θ is the incident angle.

[0022] Specifically, the Fresnel reflection coefficient r of the horizontally polarized light p Fresnel reflection coefficient r of vertically polarized light s According to Fresnel's equations:

[0023]

[0024]

[0025]

[0026]

[0027]

[0028]

[0029] in, This represents the reflection coefficient of horizontally polarized light at the interface formed between the first layer of medium and the two-dimensional material. This represents the reflection coefficient of horizontally polarized light at the interface formed between a two-dimensional material and a substrate medium. This represents the reflection coefficient of vertically polarized light at the interface formed between the first-layer medium and the two-dimensional material. θ represents the reflection coefficient of vertically polarized light at the interface formed between a two-dimensional material and a substrate medium. m θ t These are the angles of refraction of the incident light in the two-dimensional material layer and the substrate medium, respectively; k m =2πn m / λ, where λ is the wavelength of the incident light, n m Let n be the refractive index of the two-dimensional material, n1 and n2 be the refractive indices of the first layer medium and the substrate medium, respectively, N be the number of two-dimensional material layers, d be the thickness of a single two-dimensional material layer, and exp be an exponential function.

[0030] Specifically, the method for obtaining the number of layers of the two-dimensional material under test is as follows: based on the Gushansen displacement measurement data set under different incident angles and the theoretical data in the Gushansen displacement theoretical database when the horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different numbers of layers, the residual sum of squares of the theoretical data and the measurement data under each layer is compared in turn, and the number of layers corresponding to the smallest residual sum of squares is taken as the number of layers of the two-dimensional material under test.

[0031] Specifically, the method for calculating the sum of squared residuals of the theoretical data and the measured data is as follows:

[0032]

[0033]

[0034] In the formula, δ represents the sum of squared residuals, and Δ GH c represents the measurement data, lΔ GHc Representing theoretical data, vx c denoted by , where c represents the residual error and c is the number of measurement data.

[0035] Specifically, the horizontally polarized incident beam has an arbitrary wavelength and an arbitrary beam waist.

[0036] Specifically, the incident angle is any angle between 0° and 90°.

[0037] Specifically, the method for measuring the Gushanshin displacement is the direct measurement method, the weak measurement method, or the interferometric method.

[0038] Specifically, one device for measuring the displacement of Gushanshin includes: a laser source, a half-wave plate, a beam expander, a polarizing prism, a focusing lens, a sample stage, a photosensitive imaging device, and a computer; the laser source, half-wave plate, beam expander, polarizing prism, and focusing lens are arranged in sequence with their centers on the same straight line and on the incident light rays on the sample stage; the photosensitive imaging device is set on the perpendicular reflected light rays of the sample stage; and the photosensitive imaging device is connected to the computer.

[0039] Specifically, the laser source is a light source capable of generating a Gaussian beam.

[0040] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0041] This invention establishes a model relating the number of two-dimensional material layers to the Gusshanshin displacement theory through direct theoretical derivation, avoiding the problem of inconsistent models. Furthermore, this invention is based on the measurement of the centroid displacement of the light spot; theoretically, the centroid displacement of the light spot does not change when the light source intensity fluctuates, thus offering higher accuracy and reliability.

[0042] This invention utilizes the excellent sensitivity of the Gushanshin displacement to the number of layers in two-dimensional materials to achieve precise measurement of the number of layers. During the measurement process, all components in the device remain stationary, thus this invention exhibits good stability and measurement accuracy.

[0043] Compared with traditional methods for measuring the number of layers in two-dimensional materials, such as Raman spectroscopy, atomic force microscopy, and transmission electron microscopy, this invention is not only simple to operate and highly efficient, but also does not damage the sample and has good application prospects. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a flowchart of the method of the present invention.

[0046] Figure 2 This is a theoretical curve of the Gushanshin displacement when a horizontally polarized beam is reflected at an incident angle of 55° to 60° in graphene with different numbers of layers, according to an embodiment of the present invention.

[0047] Figure 3 This is a schematic diagram of a device for measuring the displacement of Gushanshin in one embodiment of the present invention, wherein 1-laser source, 2-half-wave plate, 3-beam expander, 4-polarizing prism, 5-focusing lens, 6-two-dimensional material sample to be measured, 7-sample stage, 8-photosensitive imaging device, and 9-computer.

[0048] Figure 4 This is a schematic diagram of the Gushanshin displacement that occurs when a horizontally polarized beam is reflected at an interface, according to an embodiment of the present invention.

[0049] Figure 5 This is a comparison of the displacement measurement data and theoretical data of Gushanshin in one embodiment of the present invention. Detailed Implementation

[0050] 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, and 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.

[0051] like Figure 1 As shown, a method utilizing Goos-Hanshin (Goos-Hanshin) A method for measuring the number of layers in a two-dimensional material using displacement (GH) includes the following steps:

[0052] S1. Based on the theoretical relationship model between two-dimensional materials with different numbers of layers and the Gus-Hansen displacement, establish a theoretical database of Gus-Hansen displacement when a horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different numbers of layers.

[0053] S2. A horizontally polarized incident beam is incident on the surface of the two-dimensional material to be measured at a certain incident angle;

[0054] S3. Using the method or apparatus for measuring the Gus-Hans-Hans displacement, obtain the Gus-Hans-Hans displacement produced by the reflected beam under the conditions of step S2.

[0055] S4. Change the incident angle sequentially and repeat step S3 to obtain a set of Gushanshin displacement measurement data under different incident angles.

[0056] S5. Compare and analyze the Gushanshin displacement measurement data obtained in step S4 at different incident angles with the Gushanshin displacement theoretical database established in step S1 when the horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different layers, and obtain the number of layers of the two-dimensional material being measured.

[0057] The theoretical relationship model between the two-dimensional materials with different numbers of layers and the Gushanshin displacement is as follows:

[0058]

[0059] in:

[0060]

[0061]

[0062] In the formula, △ GH (N) represents the Gushanshin displacement, δ GH Represents the spatial displacement of Gushanshin, Θ GH This represents the angular displacement of Gushanshin; τ1, Γ1, κ1, and κ2 are all intermediate parameters; z r R represents the propagation distance of the reflected beam. p The Fresnel reflection coefficient r of horizontally polarized light p The modulus of R s The Fresnel reflection coefficient r represents vertically polarized light. s The modulus of φ; p The Fresnel reflection coefficient r of horizontally polarized light p phase, φ s The Fresnel reflection coefficient r represents vertically polarized light. s The phase; Re denotes taking the real part of a complex number, and Im denotes taking the imaginary part of a complex number; z R k represents the Rayleigh length of the incident beam. r The wavenumber of the reflected beam is represented by N, where N is the number of two-dimensional material layers and θ is the incident angle.

[0063] The Fresnel reflection coefficient r of the horizontally polarized light p Fresnel reflection coefficient r of vertically polarized light s According to Fresnel's equations:

[0064]

[0065] in, This represents the reflection coefficient of horizontally polarized light at the interface formed between the first layer of medium and the two-dimensional material. This represents the reflection coefficient of horizontally polarized light at the interface formed between a two-dimensional material and a substrate medium. This represents the reflection coefficient of vertically polarized light at the interface formed between the first-layer medium and the two-dimensional material. The reflection coefficient represents the reflection of vertically polarized light at the interface formed between a two-dimensional material and a substrate medium; θ is the incident angle. m θ t These are the angles of refraction of the incident light in the two-dimensional material layer and the substrate medium, respectively; k m =2πn m / λ, where λ is the wavelength of the incident light, n m Let n be the refractive index of the two-dimensional material, n1 and n2 be the refractive indices of the first layer medium and the substrate medium, respectively, N be the number of two-dimensional material layers, and d be the thickness of a single two-dimensional material layer.

[0066] According to equation ①, the GH displacement Δ can be obtained when a horizontally polarized beam irradiates the surface of a two-dimensional material with different numbers of layers at different incident angles θ. GH . Figure 2 This is a theoretical curve of the GH displacement when a horizontally polarized beam is incident at angles of 55° to 60° on graphene with different numbers of layers. It can be seen that the GH displacement curves are significantly different for different numbers of layers. Therefore, if a set of GH displacement measurement data at different incident angles is obtained, the number of layers in the measured two-dimensional material can be determined based on the theoretical relationship database between two-dimensional materials and GH displacement.

[0067] The following is combined Figures 3 to 5 The following details the specific implementation process of an embodiment of the present invention:

[0068] In this embodiment, the device for measuring the displacement of Gushanshin is as follows: Figure 3 As shown, this device is a conventional and general-purpose device for measuring GH displacement, including a laser source 1, a half-wave plate 2, a beam expander 3, a polarizing prism 4, a focusing lens 5, a sample stage 7, a photosensitive imaging device 8, and a computer 9. The centers of the laser source 1, half-wave plate 2, beam expander 3, polarizing prism 4, and focusing lens 5 are aligned on a straight line and on the incident light beam of the sample stage 7. The photosensitive imaging device 8 is positioned on the perpendicularly reflected light beam of the sample stage 7 and is connected to the computer 9.

[0069] Among them, laser source 1 is used to generate incident polarized beam, half-wave plate 2 is used to adjust light intensity, beam expander 3 is used to expand the beam waist of polarized beam, polarizing prism 4 is used to adjust polarization state of polarized beam, focusing lens 5 is used to focus polarized beam, sample stage 7 is used to place the two-dimensional material sample 6 to be tested, photosensitive imaging device 8 is used to acquire light spot image, and computer 9 is used to calculate Gushanshin displacement value through the acquired light spot image.

[0070] The method for measuring GH displacement using the above-mentioned device is as follows: The two-dimensional material sample 6 to be tested is placed on the sample stage 7. The polarized beam generated by the laser source 1 passes perpendicularly through the center of the half-wave plate 2, beam expander 3, polarizing prism 4, and focusing lens 5 to illuminate the two-dimensional material sample 6. The polarized beam undergoes beam polarization splitting due to the Gusshanshin displacement on the surface of the two-dimensional material sample, such as... Figure 4 As shown, the polarized beam is reflected perpendicularly to the photosensitive imaging device 8. The photosensitive imaging device 8 sends the captured light intensity image to the computer 9, which then uses the centroid equation to calculate the centroid coordinates of the captured light intensity image. Let the centroid coordinates when the Gushanshin displacement is 0 be the origin. Subtracting the origin from the centroid coordinates of the captured light intensity image yields the Gushanshin displacement lΔ at that incident angle. GH .

[0071] In this embodiment, the photosensitive imaging device 8 is a camera, and a helium-neon laser is selected as the laser source. The wavelength of the polarized beam emitted by this laser source is 632.8 nm. The polarization state of the incident polarized beam is adjusted by rotating the polarizing prism 4. The incident angle of the polarized beam is adjusted by rotating the sample stage 7. The first layer dielectric material and the substrate dielectric material are air and BK7 glass, respectively, and the two-dimensional material sample being tested is graphene.

[0072] (1) Based on equation ①, establish a theoretical database of Gushanshin displacements [θ] when horizontally polarized beams are reflected from graphene surfaces of different layers at incident angles of 55° to 60° (incident interval of 0.25°). c ,lΔ GHc ],c∈{1,2,……,21}.

[0073] (2) The horizontally polarized beam is incident on the surface of the two-dimensional material sample to be tested at an incident angle of 55°.

[0074] (3) Measurement steps (2) GH displacement at the incident angle.

[0075] (4) Change the incident angle θ at intervals of 0.25° and repeat step (3) until the incident angle reaches 60°, thereby obtaining a set of GH displacement measurement data at different incident angles [θ]. c ,Δ GHc ],c∈{1,2,……,21}.

[0076] (5) Figure 5 As shown, different incident angles θ obtained through step (4) will be... c Measurement data set of GH displacement under [θ] c ,Δ GHc ], and the corresponding GH theoretical displacement [θ] of graphene of each layer number obtained through step (1). c ,lΔ GHc A comparative analysis was conducted, comparing the residual sum of squares δ of theoretical and measured data for each layer. The layer number corresponding to the smallest residual sum of squares δ was taken as the layer number of the tested two-dimensional material sample. The specific calculation method for the residual sum of squares δ is as follows:

[0077]

[0078] In the formula, δ represents the sum of squared residuals, and Δ GH c represents the measurement data, lΔ GHc Representing theoretical data, vx c This represents the residual error.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement method, characterized in that, Includes the following steps: S1. Based on the theoretical relationship model between two-dimensional materials with different numbers of layers and the Gus-Hansen displacement, establish a theoretical database of Gus-Hansen displacement when a horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different numbers of layers. S2. A horizontally polarized incident beam is incident on the surface of the two-dimensional material to be measured at a certain incident angle; S3. Using the method or apparatus for measuring the Gus-Hans-Hans displacement, obtain the Gus-Hans-Hans displacement produced by the reflected beam under the conditions of step S2. S4. Change the incident angle sequentially and repeat step S3 to obtain a set of Gushanshin displacement measurement data under different incident angles. S5. Compare and analyze the Gushansen displacement measurement data obtained in step S4 at different incident angles with the theoretical data in the Gushansen displacement theoretical database established in step S1 when the horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different layers, and obtain the number of layers of the two-dimensional material being measured.

2. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 1, characterized in that, The theoretical relationship model between the two-dimensional materials with different numbers of layers and the Gushanshin displacement is as follows: in: In the formula, △ GH (N) represents the Gushanshin displacement, δ GH Represents the spatial displacement of Gushanshin, Θ GH This represents the angular displacement of Gushanshin; τ1, Γ1, κ1, and κ2 are all intermediate parameters; z r R represents the propagation distance of the reflected beam. p The Fresnel reflection coefficient r of horizontally polarized light p The modulus of R s The Fresnel reflection coefficient r represents vertically polarized light. s The modulus of φ; p The Fresnel reflection coefficient r of horizontally polarized light p phase, φ s The Fresnel reflection coefficient r represents vertically polarized light. s The phase; Re denotes taking the real part of a complex number, and Im denotes taking the imaginary part of a complex number; z R k represents the Rayleigh length of the incident beam. r The wavenumber of the reflected beam is represented by N, where N is the number of two-dimensional material layers and θ is the incident angle.

3. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 2, characterized in that, The Fresnel reflection coefficient r of the horizontally polarized light p Fresnel reflection coefficient r of vertically polarized light s According to Fresnel's equations: in, This represents the reflection coefficient of horizontally polarized light at the interface formed between the first layer of medium and the two-dimensional material. This represents the reflection coefficient of horizontally polarized light at the interface formed between a two-dimensional material and a substrate medium. This represents the reflection coefficient of vertically polarized light at the interface formed between the first-layer medium and the two-dimensional material. θ represents the reflection coefficient of vertically polarized light at the interface formed between a two-dimensional material and a substrate medium. m θ t These are the angles of refraction of the incident light in the two-dimensional material layer and the substrate medium, respectively; k m =2πn m / λ, where λ is the wavelength of the incident light, n m Let n be the refractive index of the two-dimensional material, n1 and n2 be the refractive indices of the first layer medium and the substrate medium, respectively, N be the number of two-dimensional material layers, d be the thickness of a single two-dimensional material layer, and exp be an exponential function.

4. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 2, characterized in that, The method for obtaining the number of layers of the two-dimensional material under test is as follows: based on the Gushansen displacement measurement data set under different incident angles and the theoretical data in the Gushansen displacement theoretical database when the horizontally polarized beam is reflected at different incident angles on the surface of two-dimensional materials with different numbers of layers, the residual sum of squares of the theoretical data and the measurement data under each layer is compared in turn, and the number of layers corresponding to the smallest residual sum of squares is taken as the number of layers of the two-dimensional material under test.

5. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 4, characterized in that, The method for calculating the sum of squared residuals of the theoretical data and the measured data is as follows: In the formula, δ represents the sum of squared residuals, and Δ GH c represents the measurement data, lΔ GHc Representing theoretical data, vx c denoted by , where c represents the residual error and c is the number of measurement data.

6. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 1 or 4, characterized in that, The horizontally polarized incident beam has an arbitrary wavelength and an arbitrary beam waist.

7. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 6, characterized in that, The incident angle is any angle between 0° and 90°.

8. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 7, characterized in that, The method for measuring the displacement of Gushanshin is the direct measurement method, the weak measurement method, or the interferometric method.

9. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 8, characterized in that, One device for measuring the displacement of Gushanshin includes: a laser source (1), a half-wave plate (2), a beam expander (3), a polarizing prism (4), a focusing lens (5), a sample stage (7), a photosensitive imaging device (8), and a computer (9); the laser source (1), half-wave plate (2), beam expander (3), polarizing prism (4), and focusing lens (5) arranged in sequence are centered on the same straight line and on the incident light on the sample stage (7), the photosensitive imaging device (8) is set on the perpendicular reflected light on the sample stage (7), and the photosensitive imaging device (8) is connected to the computer (9).

10. The method for measuring the number of layers in a two-dimensional material using the Gusshamsen displacement according to claim 9, characterized in that, The laser source (1) is a light source capable of generating a Gaussian beam.

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