A device and method for automatically measuring photon spin Hall effect

Abstract

The present invention discloses an automatic measurement device and method for the photon spin Hall effect, comprising a light source system, a polarization control system, a sample stage system, a sensing and detection system, and a data acquisition and control system. The light source system includes a tunable laser and an aperture. The polarization control system includes a first electrically controlled polarizer and a second electrically controlled polarizer, which electronically control the polarization state of light, a first polarizer, a second polarizer, a horizontal positioning mechanism, a prism, and a half-wave plate. The present invention utilizes electrically controlled polarizers, a high-precision electric rotation stage, and a sample control console to precisely adjust experimental parameters, ensuring high-precision and repeatable measurements. Furthermore, a high-resolution CCD and photodetector are used to collect real-time data on the lateral displacement and intensity of the light beam, and a data acquisition card is used for rapid data transmission and processing. An integrated software system enables fully automated control of the experiment, simplifying the operational process and improving experimental 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 automatically measuring photon spin Hall effect. Background Art

[0002] The photon spin Hall effect (PSHE) is an important optical phenomenon involving the lateral displacement of a propagating light beam due to spin-orbit coupling. This effect holds great promise for applications in high-sensitivity optical sensing and nanoscale imaging. However, existing instruments and devices for measuring the PSHE require adjusting the Brewster angle to achieve the desired spin state under different conditions or for related research. This adjustment method involves manually rotating the stage left and right, visually locating the point of incidence at the Brewster angle where the reflected light spot is weakest. Furthermore, manual adjustments are required to adjust the incident angle, the polarization state of the polarizer, and the distance between optical components after changing them for different experiments. These adjustments often lack accurate feedback, which can be crucial for successful observation of the PSHE or experiment. This repeated adjustment process is time-consuming, yields unsatisfactory results, is inefficient, and susceptible to human error. Therefore, we have developed a highly integrated spectrometer that overcomes these challenges and meets the research needs for high precision and 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 in the present invention is:

[0005] A device for automatically measuring the photon spin Hall effect, comprising 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 light and an aperture for ensuring that 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 to the first electrically controlled polarizer and the second electrically controlled polarizer;

[0008] The sample stage system includes a high-precision electric rotation stage for precisely 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 precisely 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 includes a V-shaped optical path bracket, a bracket rotation mechanism, a horizontal rotating base, and a sample control console arranged on the horizontal rotating base. The V-shaped optical path bracket includes 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 rotation mechanism, so that when the bracket rotation mechanism rotates, the incident optical path rotates in the XOY plane accordingly; the tunable laser, aperture, half-wave plate, lens, and first polarizer are arranged on the outgoing optical path bracket from top to bottom, and the second polarizer, second lens, and high-resolution CCD are arranged on the outgoing optical path bracket from bottom to top.

[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 set 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, the laser is fixed on the laser bracket through a locking nut, and the laser bracket is fixed to the 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, and then drives the movement of the horizontal teeth to achieve horizontal control, so that the optical devices fixed thereon can adjust the spacing required for the experiment.

[0016] The bracket rotation 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 bracket and the output light path bracket fixed on the bracket rotation 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 to control the horizontal positioning mechanism and thus realize forward and backward movement.

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

[0020] A: When the system is initialized, the linearly polarized Gaussian beam generated by the tunable laser passes through the aperture in turn to filter out some stray light. A 1 / 2 wave plate is used as the half-wave plate. The light intensity is adjusted by the 1 / 2 wave plate to avoid detector saturation. After passing through the first lens 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, it converges on the inclined surface of the prism and automatically controls to find the Brewster angle. The specific process is as follows:

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

[0022] S2: image preprocessing;

[0023] S2.1 Grayscale, 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: Gaussian filtering is used 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 grayscale 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;

[0026] S3: Light intensity calculation and analysis;

[0027] S3.1 Light intensity calculation, the filtered gray value F 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 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 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-coordinate and y-coordinate 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 the 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 ), 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: A weak interaction occurs between the system and the instrument, i.e., a weak measurement. When the light beam is reflected at the air-prism interface, a 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 250mm plano-convex lens and a second polarizer with a high extinction ratio, and then enters the high-resolution CCD for image acquisition. The experiment ends and all experimental data and analysis results are saved.

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

[0040] The present invention utilizes an electrically controlled polarizer, a high-precision electric rotation stage, and a sample control console to precisely adjust experimental parameters, ensuring high-precision and repeatable measurements. Furthermore, a high-resolution CCD camera and photodetector collect real-time data on the beam's lateral displacement and intensity, while a data acquisition card enables rapid data transmission and processing. A variable-refractive-index medium cartridge and gas control system enable simulation of diverse experimental environments to study the impact of environmental changes on the SHEL effect. An integrated software system enables fully automated experimental control, streamlining operational procedures and improving 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 following briefly introduces the drawings required for use in the embodiments or the description of the prior art. 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 any 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 structural schematic 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 Schematic diagram of the process of automatically controlling the search for the Brewster angle in the present invention. DETAILED DESCRIPTION

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention 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 that 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 of light (linear polarization, circular polarization, elliptical polarization), 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 rotation stage 5 for accurately controlling the incident angle and a sample control console 23 for adjusting the sample temperature to study the effect 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 rotation 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 rotation mechanism, so that the incident optical path rotates in the XOY plane when the rotating stage rotates. The tunable laser 6, aperture 8, half-wave plate 9, first lens 10 and first polarizer 11 are arranged on the outgoing optical path bracket from top to bottom, and the second polarizer 14, second lens 16 and high-resolution CCD 17 are arranged on the outgoing optical path bracket from bottom to top.

[0054] The half-wave plate 9, first lens 10, first polarizer 11, second electrically controlled polarizer 15, and second lens 16 are all fixed to a V-shaped optical path bracket via horizontal positioning mechanisms. Specifically, the half-wave plate 9, first lens 10, and first polarizer 11 are all fixed to a first horizontal positioning mechanism 30, a second horizontal positioning mechanism 31, and a third horizontal positioning mechanism 32, respectively; the second electrically controlled polarizer 15 and second lens 16 are fixed via a fourth horizontal positioning mechanism 33 and a fifth horizontal positioning mechanism 34, respectively, to facilitate adjustment of the spacing and positional relationship between them. 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 by a stepping motor 21 to rotate; the sample console 23 is fixedly set on the high-precision electric rotating platform; specifically, the present invention is 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 platform 5 rotates.

[0056] It also includes a lifting device, which is set 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 lower end of the first base plate 1.

[0057] The bracket rotation mechanism includes a rotating motor, a rotating shaft, and a base plate. The rotating motor controls the rotating shaft to rotate in space, thereby driving the incident light path bracket and the outgoing light path bracket fixed to the bracket rotation mechanism to rotate as needed. Specifically, the incident light path bracket 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 is controlled by the rotating motor 36 to rotate in space. 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 and lowering. The first rotating circular shaft 37 is embedded with the second substrate 38, and the incident light arm is integrated on the second substrate 38. That is, the lifting motor 3 can realize the lifting and lowering of the entire incident light arm during lifting and lowering, 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 prioritized in actual experiments and are determined according to 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 fixed to one side of the base counterweight platform 4, and the second rotating circular shaft 19 is fixed to the third substrate 40 through the fourth substrate 20. The second rotating motor 18 provides power to the second rotating circular shaft 19, thereby controlling the rotation of the output light path bracket in the vertical plane, thereby adjusting the angle between the incident light path and the output light path. The above adjustments can all be automatically controlled by a computer; no further details will be given here.

[0059] It also includes a laser bracket 7, the laser is fixed on the laser bracket 7 through 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 rotation of the horizontal controller 29 drives 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 denoted by 15 (same as denoted by 12 ) can arbitrarily realize the polarization angle between the first polarizer and the second polarizer by controlling it.

[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 independently 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-like rotation, and cooperate with the base counterweight platform to realize the free adjustment of the incident optical path and the reflected optical path 360 degrees in space, 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 research on various topics related to the optical spin Hall effect.

[0064] In the past, readings from 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, there is no need for manual observation of these variables. Instead, we control the actual movement of the device and achieve precise 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 is fixed to the tunable laser 6 by 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, horizontal controller 29 is internally equipped with a displacement controller for horizontal control and a feedback sensor for forward and backward movement control. In reflected optical path II, by controlling first electrically controlled polarizer 12 and second electrically controlled polarizer 15, the polarization angle between the first and second polarizers can be arbitrarily adjusted to meet the requirements of comparative experiments and demonstrations.

[0067] The sample console 23 of the present invention has an internal electrically controlled rotation mechanism that independently controls the sample stage rotation. The prism 13 is also fixed to the sample console. To find the Brewster angle required for the experiment, we employ an advanced control system that uses a light sensor to record the intensity changes of the reflected light within a certain rotation angle. By comparing light intensities, we accurately locate the angle with the lowest light intensity, quickly finding the Brewster angle. To observe the spin states of photons incident at different angles, we simply input the angle we want to change, allowing for rapid 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 coordinated with the horizontal controller inside to realize horizontal control. A feedback sensor is provided to realize the mechanical structure of forward and backward movement, so that the optical device fixed on it can adjust the spacing required for the experiment.

[0069] The practical functions of this mechanical device can be summarized as follows: the stepper motor 21 controls the rotation of the high-precision rotation stage, ultimately achieving rotation of the incident light path in the XOY horizontal plane. The lifting motor independently controls the vertical elevation of the incident light path and the reflected light path, and the rotation motor independently controls the rotation of the incident light path and the reflected light path in the XOZ plane. In other words, the motors can flexibly control the spatial adjustment of the incident and reflected light paths 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 sequence to filter out some stray light. The half-wave plate 9 uses a 1 / 2 wave plate to adjust the light intensity to avoid detector saturation. After passing 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, it converges on the inclined surface of the prism 13 and automatically controls to 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 capture images of the laser spot. Set the acquisition frequency to f (unit: Hz) and the acquisition time to T (unit: s). The number of images collected is N = f * T.

[0073] S2: Image preprocessing

[0074] S2.1 Grayscale, 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), and 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 grayscale 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 filtered gray value F 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-coordinate and y-coordinate 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 the 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, a 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. The experiment ends and all experimental data and analysis results are saved.

[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, for directional words, such as the terms "center", "horizontal", "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 scope of protection 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 this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes 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 are 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 technology used. 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 detail through the above embodiments, the present invention is not limited to the specific embodiments described herein. Without departing from the concept of the present invention, it may also include many other effective embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A device for automatically measuring the photon spin Hall effect, characterized in that: Including light source system, polarization control system, sample stage system, sensing and detection system, data acquisition and control system; The light source system includes a tunable laser for providing stable and adjustable wavelength laser light and an aperture for ensuring that 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 to the first electrically controlled polarizer and the second electrically controlled polarizer; The sample stage system includes a high-precision electric rotation stage for precisely 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 precisely 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 includes a V-shaped optical path bracket, a bracket rotation mechanism, a horizontal rotating base, and a sample control console arranged on the horizontal rotating base. The V-shaped optical path bracket includes 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 rotation mechanism, so that when the bracket rotation mechanism rotates, the incident optical path rotates in the XOY plane accordingly; the tunable laser, aperture, half-wave plate, lens, and first polarizer are arranged on the outgoing optical path bracket from top to bottom, and the second polarizer, second lens, and high-resolution CCD are arranged on the outgoing optical path bracket from bottom to top. 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 photon spin Hall effect measurement device 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 set on the high-precision electric rotating table.

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

5. The automatic photon spin Hall effect measurement device 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, and then drives the movement of the horizontal teeth to achieve horizontal control, so that the optical devices fixed thereon can adjust the spacing required for the experiment.

6. The automatic photon spin Hall effect measurement device according to claim 5, characterized in that: The bracket rotation 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 bracket and the output light path bracket fixed on the bracket rotation mechanism to rotate as needed.

7. The automatic photon spin Hall effect measurement 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 measurement 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 to control the horizontal positioning mechanism and thus realize forward and backward movement.

9. The automatic measurement method based on the automatic measurement device for photon spin Hall effect according to claim 1, characterized in that: The specific steps include: A: When the system is initialized, the linearly polarized Gaussian beam generated by the tunable laser passes through the aperture in turn to filter out some stray light. A 1 / 2 wave plate is used as the half-wave plate. After the half-wave plate adjusts the light intensity to avoid detector saturation, the beam passes through the first lens (plano-convex lens L1 with a focal length of 50mm) and the first polarizer (polarizer P with a high extinction ratio) and 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 capture images of the laser spot; set the acquisition frequency to f and the acquisition time to T, then the number of images collected is N = f*T; S2: image preprocessing; S2.1 Grayscale, 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: Gaussian filtering is used to filter and denoise the grayscale image; the kernel function of Gaussian filtering is: Among them, (u, v) is the coordinate of the pixel in the kernel, σ is the standard deviation of the Gaussian kernel, which determines the degree of filtering; for each pixel point (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; S3: Light intensity calculation and analysis; S3.1 Light intensity calculation, the filtered gray value F n (x, y) is the light intensity value I of the pixel (x, y) light，n Approximation of (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 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-coordinate and y-coordinate 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, where n = 0, 1, ..., N-1: For each row x in the image, x=0,1,…,X-1: For each column y in the 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 ), 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: A weak interaction occurs between the system and the instrument, i.e., a weak measurement. When the light beam is reflected at the air-prism interface, a 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 250mm plano-convex lens and a second polarizer with a high extinction ratio, and then enters the high-resolution CCD for image acquisition. The experiment ends and all experimental data and analysis results are saved. D: Generate an experimental report, record experimental parameters and analysis conclusions.

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