Automatic measurement device and method for photon spin Hall effect

Abstract

The invention discloses an automatic measurement device and method for a photon spin Hall effect. The automatic measurement device comprises a light source system, a polarization control system, a sample table system, a sensing and detecting system and a data acquisition and control system, the light source system comprises a tunable laser and a diaphragm; the polarization control system comprises a first electric control polarizer, a second electric control polarizer, a first polarizer, a second polarizer, a horizontal positioning mechanism, a triangular prism and a half-wave plate, wherein the first electric control polarizer and the second electric control polarizer electronically control the polarization state of light. Through the electric control polarizer, the electric high-precision rotating table and the sample control table, accurate adjustment of experimental parameters is realized, and high precision and high repeatability of measurement are ensured. Furthermore, light beam transverse displacement and light intensity data are collected in real time through a high-resolution CCD and a photoelectric detector, and rapid data transmission and processing are carried out through a data collection card. The integrated software system realizes full-automatic control of the experiment, simplifies the operation process, and improves the experiment efficiency.

Description

Technical Field

[0001] The present invention relates to the field of automatic measurement technology, and in particular to a device and method for automatic measurement of photon spin Hall effect. Background Art

[0002] The photon spin Hall effect is an important optical phenomenon, which refers to the lateral displacement of the light beam during propagation due to the spin-orbit coupling effect. This effect has broad application prospects in the fields of high-sensitivity optical sensing and nanoscale imaging. However, at present, the existing instruments or devices for measuring the photon spin Hall effect need to adjust the required Brewster angle first when measuring the photon spin state under different conditions or related scientific research. The existing method of adjusting the angle is to manually rotate the stage left and right, and use the naked eye to find the position where the reflected light spot is the weakest, which is the incident point of the Brewster angle. In addition, it is necessary to manually adjust the incident angle, the polarization state of the polarizer, and the distance between the optical elements after replacing them in different experiments. After manual adjustment, it is not possible to provide good feedback on whether the adjustment is in place. These are the decisive factors for whether the photon spin Hall effect or experiment can be successfully observed. In the process of repeated adjustment, a lot of time is wasted, but the results are not necessarily ideal, the efficiency is low, and it is easily affected by human errors. In this case, we have developed a highly integrated spectrometer that can overcome the above difficulties to meet the research needs of high precision and high repeatability. Summary of the invention

[0003] The purpose of the present invention is to provide a device and method for automatically measuring the photon spin Hall effect, which can automatically perform relevant measurements and experiments and avoid errors caused by human operation.

[0004] The technical solution adopted by the present invention is:

[0005] A photon spin Hall effect automatic measurement device, including a light source system, a polarization control system, a sample stage system, a sensing and detection system, and a data acquisition and control system;

[0006] The light source system includes a tunable laser for providing stable and adjustable wavelength laser and an aperture for ensuring the light and quantity meet the experimental requirements;

[0007] The polarization control system includes a first electrically controlled polarizer and a second electrically controlled polarizer for electronically controlling the polarization state of light, a first polarizer, a second polarizer, a horizontal positioning mechanism, a prism and a half-wave plate; the first polarizer and the second polarizer are respectively fixed on the first electrically controlled polarizer and the second electrically controlled polarizer;

[0008] The sample stage system includes a high-precision electric rotating stage for accurately controlling the incident angle and a sample control console for adjusting the sample temperature to study the effect of temperature on SHEL. The sensing and detection system includes a high-resolution CCD for capturing the lateral displacement of the light beam and for accurately measuring the light intensity distribution. The prism is fixed on the sample control console.

[0009] The data acquisition and control system includes a high-resolution CCD for collecting experimental data and a computer and control software for experimental control, data acquisition and real-time analysis;

[0010] The high-precision electric rotating stage comprises a V-shaped optical path bracket, a bracket rotating mechanism, a horizontal rotating base and a sample control console arranged on the horizontal rotating base, wherein the V-shaped optical path bracket comprises an incident optical path bracket and an outgoing optical path bracket, and the incident optical path bracket and the outgoing optical path bracket are respectively fixedly connected by the bracket rotating mechanism, so that when the bracket rotating mechanism rotates, the incident optical path rotates in the XOY plane accordingly; the tunable laser, the aperture, the half-wave plate, the lens and the first polarizer are arranged on the outgoing optical path bracket in sequence from top to bottom, and the second polarizer, the second lens and the high-resolution CCD are arranged on the outgoing optical path bracket in sequence from low to high;

[0011] The half-wave plate, the first lens, the first polarizer, the second electrically controlled polarizer and the second lens are all fixed on the horizontal positioning mechanism.

[0012] The horizontal rotating base includes a base counterweight platform and a circular rotating mechanism. The circular rotating mechanism includes a controller and a rotating motor. The high-precision rotating table is rotated by the rotating motor. The sample control console is fixedly arranged on the high-precision electric rotating table.

[0013] It also includes a lifting device, which is arranged on one side of the base counterweight platform and is used to adjust the height of the base counterweight platform, thereby realizing the change of the space below the entire equipment.

[0014] It also includes a laser bracket, on which the laser is fixed through a locking nut, and the laser bracket is fixed to an incident light path bracket at the bottom.

[0015] The horizontal positioning mechanism includes an internal guide rail bracket, horizontal teeth, gears and a horizontal controller. The horizontal controller rotates to drive the gears to rotate, thereby driving the movement of the horizontal teeth to achieve horizontal control, so that the optical device fixed thereon can adjust the spacing required for the experiment.

[0016] The support rotating mechanism includes a vertically arranged base plate, a rotating motor and a rotating circular shaft. The rotating circular shaft is controlled by the rotating motor to rotate in space, thereby driving the incident light path support and the output light path support fixed on the support rotating mechanism to rotate as needed.

[0017] The focal length of the second lens is 250 mm.

[0018] The sensing and detection system also includes a feedback sensor, the output end of which is connected to the input end of the data acquisition and control system, and is used to control the horizontal positioning mechanism to achieve forward and backward movement.

[0019] The automatic measurement method based on the photon spin Hall effect automatic measurement device specifically comprises the following steps:

[0020] A: System initialization, the linearly polarized Gaussian beam generated by the tunable laser passes through the aperture in turn to filter out some stray light, and the half-wave plate uses a 1 / 2 wave plate. After the 1 / 2 wave plate adjusts the light intensity to avoid detector saturation, it passes through the first lens with a focal length of 50mm, i.e., the plano-convex lens L1 and the first polarizer, i.e., the polarizer P with a high extinction ratio, and then converges on the inclined surface of the prism to automatically control and find the Brewster angle. The specific process is as follows:

[0021] S1: Image acquisition, using a high-resolution CCD camera to continuously acquire images of the laser spot; setting the acquisition frequency to f and the acquisition time to T, the number of acquired images is N = f*T;

[0022] S2: Image preprocessing;

[0023] S2.1 Grayscale conversion: for the collected color image I n (x, y, c), where n represents the image number (n = 0, 1,, N-1), x and y represent the pixel coordinates in the image respectively; x = 0, 1, ..., X-1; y = 0, 1, ..., Y-1, X and Y are the horizontal and vertical resolutions of the image respectively; c represents the color channel c = 0 represents the red channel, c = 1 represents the green channel, and c = 2 represents the blue channel. The weighted average method is used for grayscale processing to obtain the grayscale image G n (x, y), the calculation formula is:

[0024] G n (X, Y) = 0.299R n (X, Y, 0) + 0.587G n (X, Y, 1) + 0.114B n (X, Y, 2);

[0025] S2.2 filtering and denoising, using Gaussian filtering method to filter and denoise the grayscale image; the kernel function of Gaussian filtering is: Where σ is the standard deviation of the Gaussian kernel, which determines the degree of filtering; for each pixel (x, y) in the image, the gray value F after filtering n (x, y) is obtained by the following convolution operation: Where k is the radius of the convolution kernel, usually k = |3σ| to ensure that the convolution kernel covers enough area;

[0026] S3: Light intensity calculation and analysis;

[0027] S3.1 Light intensity calculation, the gray value F after filtering n (x, y) is used as an approximation of the light intensity value I(light,n)(x,y) of the pixel point (x, y); considering the response characteristics of the light detector, a linear calibration model is used: I ligjt，n (x, y) = a F n (x, y) + b where a and b are calibration coefficients, which can be obtained by measuring and fitting a standard light source of known light intensity;

[0028] S3.2 Find the weakest light intensity point

[0029] S3.2.1 Initialize variables, define variable Imin to store the minimum light intensity value, initialize it to a larger value X

[0030] Definition I min =max(x,y,n){I light，n (x, y)}x min ,y min They are used to store the x and y coordinates of the minimum light intensity point, initialized to x min =0,y min =0;

[0031] S3.2.2 2. Traverse the image, for each image n (n = 0, 1, ..., N-1):

[0032] For each row x in the image (x=0,1,…,X-1):

[0033] For each column y in this row (y=0,1,…,Y-1):

[0034] Get the light intensity value I of the current pixel light，n (x, y);

[0035] If I light，n (x, y) min , reset I min For I light，n (x, y) continues to loop until I min =(x min ,y min );

[0036] S4 result output, output minimum light intensity value I min And the corresponding coordinates (x min ​,y min ), which represents the position and intensity value of the point with the weakest light intensity in the entire laser spot image sequence, and the incident angle of the Brewster angle can be found;

[0037] B: There is a weak interaction between the system and the instrument, i.e. weak measurement; when the light beam is reflected at the air-prism interface, photon spin-orbit interaction occurs, producing the optical spin Hall effect;

[0038] C: After being reflected, the light beam passes through the second lens, which is a plano-convex lens with a focal length of 250mm and a second polarizer with a high extinction ratio, and then enters the high-resolution CCD for image acquisition, ending the experiment and saving all experimental data and analysis results;

[0039] D: Generate an experimental report, recording experimental parameters and analysis conclusions.

[0040] The present invention realizes precise adjustment of experimental parameters through an electrically controlled polarizer, an electrically driven high-precision rotating stage and a sample control console, ensuring high precision and high repeatability of the measurement. Furthermore, a high-resolution CCD camera and a photodetector are used to collect the lateral displacement and light intensity data of the light beam in real time, and a data acquisition card is used for rapid data transmission and processing. The refractive index variable medium box and the gas control system can simulate different experimental environments and study the influence of environmental changes on the SHEL effect. The integrated software system realizes full automation control of the experiment, simplifies the operation process and improves the experimental efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a structural schematic diagram of the present invention;

[0043] Figure 2 is a flow chart of the present invention;

[0044] Figure 3 This is a schematic structural diagram of the horizontal rotating base of the present invention;

[0045] Figure 4 This is a schematic diagram of the internal structure of the horizontal positioning mechanism described in the present invention.

[0046] Figure 5 The figure is a schematic diagram of the process of automatically controlling the search for the Brewster angle in the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] like Figure 1 , 2 , 3 and 4, the present invention includes a light source system, a polarization control system, a sample stage system, a sensing and detection system, and a data acquisition and control system;

[0049] The light source system includes a tunable laser 6 for providing stable and adjustable wavelength laser light and an aperture 8 for ensuring the light and quantity meet the experimental requirements;

[0050] The polarization control system includes a first electrically controlled polarizer 12 and a second electrically controlled polarizer 15 for electronically controlling the polarization state (linear polarization, circular polarization, elliptical polarization) of light, a first polarizer 11, a second polarizer 14, a horizontal positioning mechanism, a prism 13 and a half-wave plate 9; the first polarizer 11 and the second polarizer 14 are respectively fixed on the first electrically controlled polarizer 12 and the second electrically controlled polarizer 15;

[0051] The sample stage system includes a high-precision electric rotating stage 5 for accurately controlling the incident angle and a sample control console 23 for adjusting the sample temperature to study the influence of temperature on SHEL. The sensing and detection system includes a high-resolution CCD camera 17 for capturing the lateral displacement of the light beam and for accurately measuring the light intensity distribution. The prism 13 is fixed on the sample control console 23.

[0052] The data acquisition and control system includes a high-resolution CCD17 for collecting experimental data and a computer and control software for experimental control, data acquisition and real-time analysis;

[0053] The high-precision electric rotating stage 5 includes a V-shaped optical path bracket, a bracket rotating mechanism, a horizontal rotating base and a sample control console 23 arranged on the horizontal rotating base, the V-shaped optical path bracket includes an incident optical path bracket and an outgoing optical path bracket, the incident optical path bracket and the outgoing optical path bracket are respectively fixedly connected by the bracket rotating mechanism, so that the incident optical path rotates in the XOY plane when the rotating stage rotates; the tunable laser 6, the aperture 8, the half-wave plate 9, the first lens 10 and the first polarizer 11 are arranged on the outgoing optical path bracket from top to bottom, and the second polarizer 14, the second lens 16 and the high-resolution CCD 17 are arranged on the outgoing optical path bracket from low to high;

[0054] The half-wave plate 9, the first lens 10, the first polarizer 11, the second electrically controlled polarizer 15, and the second lens 16 are fixed on the V-shaped optical path bracket through the horizontal positioning mechanism. Specifically, the half-wave plate 9, the first lens 10, and the first polarizer 11 are fixed on the first horizontal positioning mechanism 30, the second horizontal positioning mechanism 31, and the third horizontal positioning mechanism 32; the second electrically controlled polarizer 15 and the second lens 16 are fixed through the fourth horizontal positioning mechanism 33 and the fifth horizontal positioning mechanism 34, respectively, so as to facilitate the adjustment of the spacing and position relationship between each other. The internal structure thereof is shown in FIG. Figure 4 shown.

[0055] like Figure 3 As shown, the horizontal rotating base includes a base counterweight platform 4 and a high-precision rotating platform 5. The high-precision rotating platform 5 is driven to rotate by a stepping motor 21; the sample control console 23 is fixedly arranged on the high-precision electric rotating platform; specifically, the present invention Figure 3 The rotating base counterweight platform 4 controls the rotating incident light path, and a spiral worm mechanical structure is provided in the rotating base counterweight platform 4 to control the rotation, wherein the left side of the worm sleeve 24 is a bearing; the worm 25 is fixed by the bearing and the worm sleeve 24; the stepper motor 21 is connected and fixed to the worm 25 through the coupling 2, and the worm 25 cooperates with the worm wheel to realize the rotation of the base counterweight platform 4, and the stepper motor 21 controls the rotation of the worm 25 by rotation, thereby driving the rotation of the worm wheel, so that the high-precision electric rotating table 5 rotates.

[0056] It also includes a lifting device, which is arranged on both sides of the base counterweight platform 4 and is used to adjust the height of the base counterweight platform to achieve the change of the space below the entire device. Figure 1 As shown in , the lifting assembly includes a first base plate 1, a lifting rail 2, and a lifting motor 3. The lifting rail 2 is fixed to the first base plate 1 by screws, and the lifting motor 3 is fixed to the lowermost end of the first base plate 1.

[0057] The support rotating mechanism includes a rotating motor, a rotating shaft and a base plate. The rotating shaft is controlled by the rotating motor to rotate in space, thereby driving the incident light path support and the outgoing light path support fixed on the support rotating mechanism to rotate as needed. Specifically, the incident light path support includes a first rotating motor 36, a first rotating shaft 37 and a second base plate 38. The lifting rail 2 in the lifting assembly is embedded in the second base plate 38. The rotating shaft 37 is embedded in the second base plate 38, and the rotating shaft 37 is controlled by the rotating motor 36 to rotate in space, and the incident light arm assembly I is integrated on the rotating shaft 37.

[0058] The lifting motor 3 can control the substrate 2 to achieve lifting, the first rotating circular shaft 37 is inlaid with the second substrate 38, and the incident light arm is integrated on the second substrate 38, that is, the lifting motor 3 can achieve the lifting of the entire incident light arm when lifting, and the rotating motor 36 can control the rotating circular shaft 37 to drive the incident light arm assembly to rotate in space. Lifting and rotation are not in order in actual experiments, depending on the specific experimental conditions. The output light path bracket includes a second rotating motor 18, a second rotating circular shaft 19, a third substrate 40 and a fourth substrate 20. The third substrate 40 is vertically fixedly set on one side of the base counterweight platform 4, the second rotating circular shaft 19 is fixedly set on the third substrate 40 through the fourth substrate 20, and the second rotating motor 18 provides power for the second rotating circular shaft 19, thereby controlling the rotation of the output light path bracket in the vertical plane, and then the angle between the incident light path and the output light path can be adjusted, and the above adjustments can be automatically controlled by a computer; no further description is given here.

[0059] It also includes a laser bracket 7, on which the laser is fixed by a locking nut, and the laser bracket 7 is fixed to the incident light path bracket at the bottom.

[0060] The horizontal positioning mechanism includes an internal guide rail bracket 26, horizontal teeth 27, and cooperates with a gear 28 and a horizontal controller 29. The horizontal controller 29 rotates to drive the gear 28 to rotate, and then drives the movement of the horizontal teeth 27 to achieve horizontal control, so that the optical devices fixed thereon can adjust the spacing between each other required for the experiment.

[0061] The electrically controlled polarizer knob device marked 15 (same as marked 12) can arbitrarily realize the polarization angle between the first polarizer and the second polarizer through control.

[0062] The focal length of the first lens is 5 cm, and the focal length of the second lens is 5 cm.

[0063] When the present application is actually used, it includes a controllable rotating stage above the fixed base counterweight platform, the stage is connected to the bottom rotation controller, and the controller is fixed to the base counterweight platform, so that the rotation angle of the stage can be controlled by the controller when the base counterweight platform is fixed. The entire optical path is divided into an incident optical path and a reflected collection optical path, both of which are fixed on coaxial equal height brackets. And an adjustment and positioning mechanical structure is provided inside, which can individually control the distance and angle between each optical element to meet the needs of the experiment. The fixed brackets on both sides can perform spatial clock rotation, and cooperate with the base counterweight platform to realize the free adjustment of the incident optical path and the reflected optical path in space 360 ​​degrees, which can meet the use in various scenarios and various related measurements. The present invention can conveniently form a measurement optical path for the photon spin Hall effect, intuitively display the photon spin phenomenon and measure the photon spin displacement, and can also conduct various research on topics related to the optical spin Hall effect.

[0064] In the past, readings of various optical measuring devices were taken from physical scales, such as reading the scales on a turntable and a central axis, and then determining the angle and distance of the optical path rotation. However, with automatic control, we do not need to observe these variables manually, but instead control the actual movement of the device and achieve accurate digital presentation through sensors.

[0065] The above-mentioned instrument bracket is composed of the following optical components:

[0066] like Figure 1 As shown, the optical path bracket is divided into an incident optical path I and a reflected optical path II. In the incident optical path I, the tunable laser bracket 7 fixes the tunable laser 6 through a locking nut, and the tunable laser bracket 7 and the aperture 8 are fixed to the bottom incident optical path bracket; Figure 4 As shown, the horizontal controller 29 is provided with a displacement controller to realize horizontal control, and a feedback sensor is provided to realize the control structure of forward and backward movement. In the reflection light path II, by controlling the first electrically controlled polarizer 12 and the second electrically controlled polarizer 15, the polarization angle between the first polarizer and the second polarizer can be arbitrarily realized to meet the requirements of comparative experiments and demonstrations.

[0067] The sample console 23 of the present invention is provided with an electric control rotating mechanism inside, and the sample stage is rotated by independent control. The prism 13 is fixed on the sample console. When searching for the Brewster angle required for the experiment, we adopt an advanced control system, which uses a light sensor to record the intensity change of the reflected light within a certain rotation angle, and then accurately finds the angle with the darkest light intensity by comparing the light intensity, and quickly finds the Brewster angle. When it is necessary to observe the spin state of photons incident at different angles, we only need to input the angle we want to change, and can quickly realize the comparison of multiple sets of data.

[0068] like Figure 4 The figure shows the internal structure of the horizontal positioning mechanism, in which the internal guide rail bracket 26 is connected to the optical arm bracket by screws, the horizontal teeth 27 are engaged with the gear structure 28, and the horizontal controller 29 is cooperated with the horizontal controller inside to realize horizontal control, and a feedback sensor is provided to realize the mechanical structure of forward and backward movement, so that the optical device fixed thereon can adjust the spacing required for the experiment.

[0069] The practical functions of the mechanical device structure can be briefly described as follows: the stepper motor 21 can control the rotation of the high-precision rotating stage by rotation, and finally realize the rotation of the incident light path in the XOY horizontal plane, the lifting motor can control the lifting of the incident light path and the reflected light path in the vertical plane, and the rotating motor can control the rotation of the incident light path and the reflected light path in the XOZ plane. That is, the incident light path and the reflected light path can be flexibly controlled by the motor to realize free adjustment in space to meet the requirements of different experiments.

[0070] When this application is actually used, it is implemented according to the following steps:

[0071] 1) System initialization, the linearly polarized Gaussian beam generated by the tunable laser 6 passes through the aperture 8 in turn to filter out some stray light, and the half-wave plate 9 uses a 1 / 2 wave plate. After the 1 / 2 wave plate adjusts the light intensity to avoid detector saturation, it passes through the first lens 10 with a focal length of 50mm, that is, the plano-convex lens L1 and the first polarizer, that is, the polarizer P with a high extinction ratio, and then converges on the inclined surface of the prism 13 to automatically control and find the Brewster angle, such as Figure 5 As shown, the algorithm flow is as follows:

[0072] S1: Image acquisition, use a high-resolution CCD camera to continuously acquire images of the laser spot. Set the acquisition frequency to f (unit: Hz) and the acquisition time to T (unit: s), then the number of images acquired is N = f*T.

[0073] S2: Image preprocessing

[0074] S2.1 Grayscale conversion: for the collected color image I n (x, y, c), where n represents the image number (n = 0, 1,, N-1), x and y represent the pixel coordinates in the image (x = 0, 1, ..., X-1; y = 0, 1, ..., Y-1, X and Y are the horizontal and vertical resolutions of the image respectively), c represents the color channel (c = 0 represents the red channel, c = 1 represents the green channel, and c = 2 represents the blue channel). The weighted average method is used for grayscale processing to obtain the grayscale image G n (x, y), the calculation formula is:

[0075] G n (X, Y) = 0.299R n (X, Y, 0) + 0.587G n (X, Y, 1) + 0.114B n

[0076] (X, Y, 2)

[0077] S2.2 filtering and denoising, using Gaussian filtering method to filter and denoise the grayscale image. The kernel function of Gaussian filtering is: Where σ is the standard deviation of the Gaussian kernel, which determines the degree of filtering. For each pixel (x, y) in the image, the gray value F after filtering n (x, y) is obtained by the following convolution operation: Where k is the radius of the convolution kernel, usually k = |3σ|, to ensure that the convolution kernel covers a sufficient area.

[0078] S3: Light intensity calculation and analysis

[0079] S3.1 Light intensity calculation, the gray value F after filtering n (x, y) is used as an approximation of the light intensity value I(light,n)(x,y) at the pixel point (x, y). Considering the response characteristics of the light detector, a linear calibration model can be used:

[0080] I light，n (x, y) = a F n (x, y)+b where a and b are calibration coefficients, which can be obtained by measuring and fitting a standard light source of known light intensity.

[0081] S3.2 Find the weakest light intensity point

[0082] S3.2.1 Initialize variables, define variable Imin to store the minimum light intensity value, initialize it to a larger value X

[0083] Definition I min =max(x,y,n){I light，n (x, y)}x min ,y min They are used to store the x and y coordinates of the minimum light intensity point, initialized to x min =0,y min =0.

[0084] S3.2.2 2. Traverse the image, for each image n (n = 0, 1, ..., N-1):

[0085] For each row x in the image (x=0,1,…,X-1):

[0086] For each column y in this row (y=0,1,…,Y-1):

[0087] Get the light intensity value I of the current pixel light，n (x, y).

[0088] If I light，n (x, y) min

[0089] Reset I min For I light，n (x, y) continues to loop until I min =(x min ,y min )

[0090] S4 result output, output minimum light intensity value I min And the corresponding coordinates (x min ,y min ​), which represents the position and intensity value of the point with the weakest light intensity in the entire laser spot image sequence, and the incident angle of the Brewster angle can be found.

[0091] 2) A weak interaction occurs between the system and the instrument, i.e., weak measurement. When the light beam is reflected at the air-prism interface, photon spin-orbit interaction occurs, producing the optical spin Hall effect.

[0092] 3) After being reflected, the light beam passes through the second lens, i.e., a plano-convex lens with a focal length of 250 mm and a second polarizer 14 with a high extinction ratio, and then enters the high-resolution CCD 17 for image acquisition, ending the experiment and saving all experimental data and analysis results.

[0093] Generate an experimental report to record experimental parameters and analysis conclusions.

[0094] In the description of the present invention, it should be noted that directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific protection scope of the present invention.

[0095] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or inherent to these processes, methods, products or apparatuses.

[0096] Note that the above are only preferred embodiments of the present invention and the principles of the application technology. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the specific embodiments described herein, and may include more other effective embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A device for automatically measuring photon spin Hall effect, characterized in that: Including light source system, polarization control system, sample stage system, sensor and detection system, data acquisition and control system; The light source system includes a tunable laser for providing stable and adjustable wavelength laser and an aperture for ensuring the light and quantity meet the experimental requirements; The polarization control system includes a first electrically controlled polarizer and a second electrically controlled polarizer for electronically controlling the polarization state of light, a first polarizer, a second polarizer, a horizontal positioning mechanism, a prism and a half-wave plate; the first polarizer and the second polarizer are respectively fixed on the first electrically controlled polarizer and the second electrically controlled polarizer; The sample stage system includes a high-precision electric rotating stage for accurately controlling the incident angle and a sample control console for adjusting the sample temperature to study the effect of temperature on SHEL. The sensing and detection system includes a high-resolution CCD for capturing the lateral displacement of the light beam and for accurately measuring the light intensity distribution. The prism is fixed on the sample control console. The data acquisition and control system includes a high-resolution CCD for collecting experimental data and a computer and control software for experimental control, data acquisition and real-time analysis; The high-precision electric rotating stage comprises a V-shaped optical path bracket, a bracket rotating mechanism, a horizontal rotating base and a sample control console arranged on the horizontal rotating base, wherein the V-shaped optical path bracket comprises an incident optical path bracket and an outgoing optical path bracket, and the incident optical path bracket and the outgoing optical path bracket are respectively fixedly connected by the bracket rotating mechanism, so that when the bracket rotating mechanism rotates, the incident optical path rotates in the XOY plane accordingly; the tunable laser, the aperture, the half-wave plate, the lens and the first polarizer are arranged on the outgoing optical path bracket from top to bottom, and the second polarizer, the second lens and the high-resolution CCD are arranged on the outgoing optical path bracket from low to high; The half-wave plate, the first lens, the first polarizer, the second electrically controlled polarizer and the second lens are all fixed on the horizontal positioning mechanism.

2. The automatic measurement device for photon spin Hall effect according to claim 1, characterized in that: The horizontal rotating base includes a base counterweight platform and a circular rotating mechanism. The circular rotating mechanism includes a controller and a rotating motor. The high-precision rotating table is rotated by the rotating motor. The sample control console is fixedly arranged on the high-precision electric rotating table.

3. The automatic photon spin Hall effect measuring device according to claim 2, characterized in that: It also includes a lifting device, which is arranged on one side of the base counterweight platform and is used to adjust the height of the base counterweight platform, thereby realizing the change of the space below the entire equipment.

4. The automatic photon spin Hall effect measuring device according to claim 2, characterized in that: It also includes a laser bracket, on which the laser is fixed through a locking nut, and the laser bracket is fixed to an incident light path bracket at the bottom.

5. The automatic measurement device for photon spin Hall effect according to any one of claims 1 to 4, characterized in that: The horizontal positioning mechanism includes an internal guide rail bracket, horizontal teeth, gears and a horizontal controller. The horizontal controller rotates to drive the gears to rotate, thereby driving the movement of the horizontal teeth to achieve horizontal control, so that the optical device fixed thereon can adjust the spacing required for the experiment.

6. The automatic measurement device for photon spin Hall effect according to claim 5, characterized in that: The support rotating mechanism includes a vertically arranged base plate, a rotating motor and a rotating circular shaft. The rotating circular shaft is controlled by the rotating motor to rotate in space, thereby driving the incident light path support and the output light path support fixed on the support rotating mechanism to rotate as needed.

7. The automatic photon spin Hall effect measuring device according to claim 5, characterized in that: The focal length of the second lens is 250 mm.

8. The automatic photon spin Hall effect measuring device according to claim 5, characterized in that: The sensing and detection system also includes a feedback sensor, the output end of which is connected to the input end of the data acquisition and control system, and is used to control the horizontal positioning mechanism to achieve forward and backward movement.

9. The automatic measurement method based on the automatic measurement device of photon spin Hall effect according to claim 1, characterized in that: The specific steps include: A: System initialization, the linearly polarized Gaussian beam generated by the tunable laser passes through the aperture in turn to filter out some stray light, and the half-wave plate uses a 1 / 2 wave plate. After the 1 / 2 wave plate adjusts the light intensity to avoid detector saturation, it passes through the first lens with a focal length of 50mm, i.e., the plano-convex lens L1 and the first polarizer, i.e., the polarizer P with a high extinction ratio, and then converges on the inclined surface of the prism to automatically control and find the Brewster angle. The specific process is as follows: S1: Image acquisition, using a high-resolution CCD camera to continuously acquire images of the laser spot; setting the acquisition frequency to f and the acquisition time to T, the number of acquired images is N = f*T; S2: Image preprocessing; S2.1 Grayscale conversion: for the collected color image I n (x, y, c), where n represents the image number (n = 0, 1,, N-1), x and y represent the pixel coordinates in the image respectively; x = 0, 1, ..., X-1; y = 0, 1, ..., Y-1, X and Y are the horizontal and vertical resolutions of the image respectively; c represents the color channel c = 0 represents the red channel, c = 1 represents the green channel, and c = 2 represents the blue channel. The weighted average method is used for grayscale processing to obtain the grayscale image G n (x, y), the calculation formula is: G n (X,Y)=0.299R n (X,Y,0)+0.587G n (X,Y,1)+0.114B n (X,Y,2); S2.2 filtering and denoising, using Gaussian filtering method to filter and denoise the grayscale image; the kernel function of Gaussian filtering is: Where σ is the standard deviation of the Gaussian kernel, which determines the degree of filtering; for each pixel (x, y) in the image, the gray value F after filtering n (x, y) is obtained by the following convolution operation: Where k is the radius of the convolution kernel, usually k = |3σ| to ensure that the convolution kernel covers enough area; S3: Light intensity calculation and analysis; S3.1 Light intensity calculation, the gray value F after filtering n (x, y) is used as an approximation of the light intensity value I(light,n)(x,y) of the pixel point (x, y); considering the response characteristics of the light detector, a linear calibration model is used: I light，n (x, y) = a F n (x, y) + b where a and b are calibration coefficients, which can be obtained by measuring and fitting a standard light source of known light intensity; S3.2 Find the weakest light intensity point S3.2.1 Initialize variables, define variable Imin to store the minimum light intensity value, initialize it to a larger value X Definition I min =max(x,y,n){I light，n (x, y)}x min ,y min They are used to store the x and y coordinates of the minimum light intensity point, initialized to x min =0,y min =0; S3.2.2 2. Traverse the image, for each image n (n = 0, 1, ..., N-1): For each row x in the image (x=0,1,…,X-1): For each column y in this row (y=0,1,…,Y-1): Get the light intensity value I of the current pixel light，n (x, y); If I light，n (x, y) min , reset I min For I light，n (x, y) continues to loop until I min =(x min ,y min );​ S4 result output, output minimum light intensity value I min And the corresponding coordinates (x min ,y min ), which represents the position and intensity value of the point with the weakest light intensity in the entire laser spot image sequence, and the incident angle of the Brewster angle can be found; B: There is a weak interaction between the system and the instrument, i.e. weak measurement; when the light beam is reflected at the air-prism interface, photon spin-orbit interaction occurs, producing the optical spin Hall effect; C: After being reflected, the light beam passes through the second lens, which is a plano-convex lens with a focal length of 250mm and a second polarizer with a high extinction ratio, and then enters the high-resolution CCD for image acquisition, ending the experiment and saving all experimental data and analysis results; D: Generate an experimental report, recording experimental parameters and analysis conclusions.

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