Wavelength-resolved Goos-Hanchen shift determination method and biochemical sensing method based on wavelength-resolved Goos-Hanchen shift determination method

Abstract

The invention relates to a wavelength-resolved Goos-Hanchen shift measuring method and a biochemical sensing method based on the wavelength-resolved Goos-Hanchen shift, and the measuring method comprises the following steps: irradiating incident light from a light source module to a sample piece on a sample table, and reflecting the incident light on the sample piece to obtain reflected light; receiving the reflected light by using a hyperspectral imaging module to obtain a hyperspectral image of a light spot of the reflected light, and extracting a grayscale image of the light spot of the reflected light under each wavelength from the hyperspectral image; and obtaining Goos-Hanchen shift of the sample piece under each wavelength according to the distribution of the light intensity along with the pixel position in the grayscale image under each wavelength. On the basis, the wavelength corresponding to the maximum Goos-Hanchen shift variation is obtained by comparing the Goos-Hanchen shift under each wavelength measured before and after the biochemical substances are attached to the surface of the sample piece, and then the biochemical substances are detected by taking the Goos-Hanchen shift under the wavelength as a sensitivity parameter.

Description

Technical Field

[0001] The present invention relates to the field of optical precision measurement, and in particular to a wavelength-resolved Goos-Hanchen shift determination method and a biochemical sensing method based thereon. Background Art

[0002] Goos-Hanchen shift is a phenomenon in which the propagation path of a non-ideal plane wave deviates from the theoretical path of geometric optics when it is reflected at an interface. It is an important research object in the current field of optics. In addition to theoretical analysis, experimental measurement is also required for the study of Goos-Hanchen shift. Existing Goos-Hanchen shift measurement methods all use laser light sources to measure Goos-Hanchen shift at a single wavelength. Goos-Hanchen shift is generated during the reflection of light at an interface. The interface reflection characteristics of light depend on the refractive index of the material on both sides of the reflection interface. Therefore, the refractive index dispersion characteristics of the material will make the Goos-Hanchen shift also have wavelength dependence characteristics. Testing and analyzing the wavelength dependence of the Goos-Hanchen shift will help to deeply understand the Goos-Hanchen shift phenomenon. However, to date, no research on the dispersion characteristics of the Goos-Hanchen shift has been reported at home and abroad. At present, displacement sensors and biochemical sensors based on Goos-Hanchen shift measurement have been reported. By performing wavelength-resolved measurement of the Goos-Hanchen shift, we can not only understand and master the wavelength dependence characteristics of the Goos-Hanchen shift, but also help to optimize the performance of such sensors. The lack of a means to quickly and accurately measure the wavelength-resolved Goos-Hanchen shift in reality has, to a certain extent, limited the further development of the corresponding sensors. Summary of the invention

[0003] In view of this, in order to solve the above problems, a wavelength-resolved Goos-Hanchen shift measurement method and a biochemical sensing method based on the same are proposed.

[0004] As a first aspect of the present invention, a wavelength-resolved Goos-Hanchen shift determination method is provided, wherein the determination method is implemented based on a hyperspectral imaging device, wherein the hyperspectral imaging device comprises a light source module, a hyperspectral imaging module, a sample stage, and a signal processing module, and the determination method comprises:

[0005] The incident light from the light source module is irradiated onto the sample placed on the sample stage, and the incident light is reflected on the sample to obtain reflected light, wherein the incident light is a visible-near infrared polarized parallel light beam; wherein the sample is configured to enable the reflected light to produce a phase difference on the surface of the sample with respect to the incident light;

[0006] The reflected light is received by the hyperspectral imaging module to obtain a hyperspectral image of the reflected light spot, and grayscale images of the reflected light spot at various wavelengths are extracted from the hyperspectral image, wherein each wavelength is in the visible-near infrared band; wherein each wavelength corresponds to a grayscale image;

[0007] The Goos-Hanchen shift of the sample at each wavelength is obtained according to the distribution of light intensity with pixel position in the grayscale image at each wavelength.

[0008] According to an embodiment of the present invention, the Goos-Hanchen shift of the sample at each wavelength is obtained according to the distribution of light intensity with pixel position in the grayscale image at each wavelength, including:

[0009] According to the distribution of light intensity with pixel position in the grayscale image at each wavelength, the light intensity centroid of the reflected light spot corresponding to each wavelength is obtained;

[0010] According to the displacement of the light intensity centroid relative to the target pixel in the grayscale image, the Goos-Hanchen shift of the sample at each wavelength is obtained.

[0011] According to an embodiment of the present invention, the target pixel is a central pixel of the grayscale image of the reflected light spot.

[0012] According to an embodiment of the present invention, the Goos-Hanchen shift is expressed as follows:

[0013]

[0014]

[0015] in, Indicates wavelength The Goos-Hanchen shift under Indicates wavelength The coordinates of the center of mass of the light intensity under The wavelength The coordinates of any pixel in the grayscale image below, for The light intensity of the pixel, The direction is the direction of the component of the wave vector of the incident light on the surface of the sample, axis is perpendicular to the wave vector component, direction, direction and the normal direction of the sample surface ( direction) satisfies the right-hand screw rule, is the size of the pixel.

[0016] According to an embodiment of the present invention, the sample stage includes: a displacement platform or a coupling prism.

[0017] According to an embodiment of the present invention, when the sample stage is a coupled prism, the sample is a chip composed of a transparent substrate and one or more thin films deposited on the transparent substrate, and the sample includes an SPR chip, a PWR chip, a resonant mirror chip, a metasurface chip, and a photonic crystal chip;

[0018] The sample is closely attached to the bottom surface of the coupling prism through the coupling liquid, and the incident light is irradiated onto the sample through the coupling prism and is totally reflected on the sample to generate the reflected light.

[0019] According to an embodiment of the present invention, the visible-near infrared linearly polarized parallel light beam is s-polarized light or p-polarized light or other linearly polarized light that can be decomposed into an s-polarized component and a p-polarized component.

[0020] According to an embodiment of the present invention, the hyperspectral imaging device further includes a lens assembly,

[0021] The lens assembly is arranged between the sample and the hyperspectral imaging module. The reflected light passes through the lens assembly and is received by the hyperspectral imaging module to obtain a hyperspectral image of the reflected light spot magnified by the lens assembly.

[0022] As a second aspect of the present invention, a biochemical sensing method based on Goos-Hanchen shift assay is also provided, comprising:

[0023] Placing the sample on the sample stage, and then placing the biochemical substance to be tested on the surface of the sample, wherein the sample stage for placing the sample is selected as a coupling prism;

[0024] Using the detection method as described above, the Goos-Hanchen shift at each wavelength before and after the biochemical substance to be tested is placed on the surface of the sample is tested to obtain the Goos-Hanchen shift change at each wavelength caused by the biochemical substance to be tested;

[0025] By comparing the Goos-Hanchen shift changes measured at various wavelengths, an optimal wavelength is determined so that the Goos-Hanchen shift change corresponding to the optimal wavelength is the largest;

[0026] By testing the Goos-Hanchen potential change at the optimal wavelength, the information of the biochemical substance to be tested is obtained;

[0027] The information of the biochemical substance to be tested includes concentration, thickness and refractive index.

[0028] According to an embodiment of the present invention, the hyperspectral image obtained by using the hyperspectral imaging module includes grayscale images at multiple wavelengths. Since each grayscale image corresponds to one wavelength, the Goos-Hanchen shift at each wavelength can be obtained according to the light intensity distribution of each grayscale image. The measurement method provided by the embodiment of the present invention can simultaneously obtain the Goos-Hanchen shift of the sample at multiple wavelengths, that is, the wavelength-resolved Goos-Hanchen shift is obtained.

[0029] According to an embodiment of the present invention, compared with the Goos-Hanchen shift measurement at a single wavelength, the simultaneous measurement of the Goos-Hanchen shift at multiple wavelengths helps us to have a more comprehensive understanding of the Goos-Hanchen shift phenomenon occurring on the surface of the sample, which is beneficial to optimizing the performance of sensors based on the Goos-Hanchen shift measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0031] Figure 1 A schematic diagram of a hyperspectral imaging device provided by an embodiment of the present invention is shown;

[0032] Figure 2 The method for measuring the wavelength-resolved Goos-Hanchen shift provided by an embodiment of the present invention is shown;

[0033] Figure 3 The central area of ​​the hyperspectral image formed by the reflected light spot on the hyperspectral imaging module in Example 1 is shown;

[0034] Figure 4 Shows Figure 3 Spectral curves of three pixel points;

[0035] Figure 5 Grayscale images of reflected light spots at several specific wavelengths in Example 1 and the Goos-Hanchen shift corresponding to each grayscale image are shown;

[0036] Figure 6 A comparison between the simulation results and experimental results of the SPR chip is given.

[0037] Description of reference numerals:

[0038] 1- Light source module;

[0039] 11- Light source;

[0040] 12- Polarizer;

[0041] 2-Hyperspectral imaging module;

[0042] 3- Sample stage;

[0043] 4- Lens assembly;

[0044] 5- Sample. DETAILED DESCRIPTION

[0045] In the process of implementing the present invention, it is found that the prior art mainly measures by comparing the difference of single-wavelength Goos-Hanchen shifts generated under different polarization modes (p-polarization mode and s-polarization mode). Using this method, combined with a wavelength scanning method based on a tunable laser or a tunable filter, it is possible to measure multi-wavelength Goos-Hanchen shifts in a narrow spectral range, but it is impossible to measure wide-spectrum Goos-Hanchen shifts from visible to near-infrared bands. There are currently no reports on wide-spectrum Goos-Hanchen shift measurements at home and abroad. The hyperspectral imager combines the functions of a spectrometer and an imager, and has the characteristics of unified graph and spectrum, wide spectral range, large number of spectral channels, and high spectral resolution, which provides an opportunity for wide-spectrum Goos-Hanchen shift measurements. By performing wavelength scanning of the Goos-Hanchen shift by a hyperspectral imaging device, displacements at thousands of wavelengths can be obtained in a single static imaging, and high-throughput Goos-Hanchen shift data can also be obtained by combining polarization mode scanning or angle scanning. The method for measuring multi-wavelength Goos-Hanchen shifts based on hyperspectral imaging is a major improvement on the basis of traditional single-wavelength Goos-Hanchen shift measurements.

[0046] In order to make the purpose, technical scheme and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. However, the present invention can be implemented in different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, providing these embodiments will make the invention thorough and complete and fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, for clarity, the sizes and relative sizes of layers and regions may be exaggerated, and the same reference numerals throughout represent the same elements.

[0047] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0048] Figure 1 A schematic diagram of a hyperspectral imaging device provided by an embodiment of the present invention is shown.

[0049] like Figure 1 As shown, the hyperspectral imaging device includes a light source module, a hyperspectral imaging module 2 and a sample stage 3.

[0050] Figure 2The method for measuring the wavelength-resolved Goos-Hanchen shift provided by an embodiment of the present invention is shown.

[0051] like Figure 2 As shown, the measuring method includes operations S10 to S30.

[0052] Operation S10 causes the incident light from the light source module to irradiate the sample 5 placed on the sample stage 3. The incident light is reflected on the sample 5 to obtain reflected light. The incident light is a visible-near infrared polarized parallel light beam. The sample 5 is configured to enable the reflected light to produce a phase difference on the sample surface relative to the incident light.

[0053] Operation S20, using the hyperspectral imaging module 2 to receive the reflected light, obtain a hyperspectral image of the reflected light spot, and extract grayscale images of the reflected light spot at each wavelength from the hyperspectral image, where each wavelength is in the visible-near infrared band; wherein each wavelength corresponds to a grayscale image.

[0054] According to an embodiment of the present invention, the hyperspectral imaging module 2 is suitable for performing imaging under various spectral channels in the visible-near infrared band, and each wavelength in operation S20 corresponds to each spectral channel of the hyperspectral imaging module.

[0055] Operation S30: obtaining the Goos-Hanchen shift of the sample at each wavelength according to the distribution of light intensity with pixel position in the grayscale image at each wavelength.

[0056] According to an embodiment of the present invention, the light source module includes a light source 11 and a linear polarizer 12. The light emitted by the light source 11 is spectrally continuous high-intensity visible-near-infrared parallel light, such as parallel white light. The light emitted by the light source 11 is converted into incident light by the linear polarizer 12.

[0057] According to an embodiment of the present invention, the hyperspectral imaging device further includes a lens assembly, and the reflected light enters the hyperspectral imaging device 2 after being focused by the lens assembly 4 .

[0058] The incident angle of the incident light on the sample is known, and the hyperspectral imaging module 2 may be, for example, a line scanning hyperspectral imaging module based on grating spectroscopy or a hyperspectral imaging module based on wavelength scanning.

[0059] According to the embodiment of the present invention, the hyperspectral image obtained by the hyperspectral imaging module 2 includes a plurality of grayscale images. Since each grayscale image corresponds to a wavelength, the Goos-Hanchen shift at the wavelength can be obtained according to the light intensity distribution of each grayscale image. The measurement method provided by the embodiment of the present invention can simultaneously obtain the Goos-Hanchen shift of the sample at multiple wavelengths, that is, the wavelength-resolved Goos-Hanchen shift is obtained.

[0060] According to the embodiment of the present invention, compared with the Goos-Hanchen shift at a single wavelength, the wavelength-resolved Goos-Hanchen shift can more accurately reflect the characteristics of the sample.

[0061] According to an embodiment of the present invention, in operation S30, the Goos-Hanchen shift of the sample at each wavelength is obtained according to the distribution of light intensity with pixel position in the grayscale image at each wavelength, including sub-operation S31 and sub-operation S32.

[0062] In sub-operation S31, the light intensity centroid of the reflected light spot corresponding to each wavelength is obtained according to the distribution of light intensity with pixel position in the grayscale image at each wavelength.

[0063] In sub-operation S32, the Goos-Hanchen shift of the sample at each wavelength is obtained according to the displacement of the light intensity centroid relative to the target pixel in the grayscale image.

[0064] According to an embodiment of the present invention, the target pixel is the central pixel of the grayscale image of the reflected light spot, and the light intensity of the central pixel is the pixel value of the central pixel.

[0065] According to an embodiment of the present invention, the Goos-Hanchen shift is expressed as follows:

[0066] (1)

[0067] (2)

[0068] in, Indicates wavelength The Goos-Hanchen shift under Indicates wavelength The coordinates of the center of mass of the light intensity under The wavelength The coordinates of any pixel in the grayscale image below, for The light intensity of the pixel, The component of the wave vector parallel to the incident light along the surface of the sample, The axis is perpendicular to the wave vector component, and the x-direction, y-direction and the normal direction of the sample surface (z-direction) satisfy the right-hand screw rule. is the size of the pixel.

[0069] According to an embodiment of the present invention, there is at least one interface in the sample 5, and the interface in the sample 5 is a plane. When there are multiple interfaces in the sample 5, the multiple interfaces form a stacked structure, and the multiple interfaces are parallel to each other. When there is only one interface in the sample 5, the sample may include only one medium. In this case, the interface in the sample is the interface between the sample and the air. In addition, the sample 5 may also be composed of multiple layers of dielectrics with different refractive indices, and interlayer reflection may occur between different layers.

[0070] According to an embodiment of the present invention, the sample stage 3 includes: a displacement platform or a coupling prism. When the displacement platform is used as the sample stage, the incident light can be directly incident on the sample, and the incident light is reflected to obtain reflected light.

[0071] According to an embodiment of the present invention, the sample 5 can be a chip that produces a measurable Goos-Hanchen shift under experimental conditions, including one of an SPR chip, a PWR chip, a resonant mirror chip, a metasurface chip, and a photonic crystal chip. Although the refractive index of all substances is theoretically related to the wavelength, the refractive index of most substances changes little in the visible-near infrared range, and the multi-wavelength Goos-Hanchen shift produced is also small. Therefore, a chip with an optical resonance structure with a large wavelength dependence can be used as a sample, such as an SPR chip, a PWR chip, a resonant mirror chip, a metasurface chip, a photonic crystal chip, etc.

[0072] When the sample stage is a coupling prism, the sample is closely attached to the bottom surface of the coupling prism through the coupling liquid, and the incident light is irradiated onto the sample through the coupling prism, and is totally reflected on the sample to generate reflected light. According to an embodiment of the present invention, the visible-near infrared polarized parallel light beam is s-polarized light or p-polarized light or other linearly polarized light that can be decomposed into s-polarized components and p-polarized components.

[0073] According to an embodiment of the present invention, the hyperspectral imaging device also includes a lens assembly 4, which is arranged between the sample 5 and the hyperspectral imaging module 2. The reflected light passes through the lens assembly 4 and is received by the hyperspectral imaging module 2 to obtain a hyperspectral image of the reflected light spot magnified by the lens assembly.

[0074] According to an embodiment of the present invention, after the Goos-Hanchen shift of a sample at multiple wavelengths is detected using the method in the embodiment of the present invention, the result obtained by the embodiment of the present invention can also be verified using the Fresnel multi-layer reflection formula. The specific verification process is as follows.

[0075] The wavelength is obtained by the Fresnel multilayer reflection formula: The incident light at the incident angle Fresnel reflection coefficient under , and according to The first-order approximation of the lateral Goos-Hanchen shift and the first-order approximation of the angular Goos-Hanchen shift are calculated.

[0076] (3)

[0077] (4)

[0078] in, Indicates wavelength The first-order approximation for the lower transverse Goos–Hanchen shift is, Indicates wavelength First-order approximation of the Goos–Hanchen shift at lower angles. is the divergence of the reflected light spot, The radius of the reflected light spot can be and the distance the reflected light travels It is obtained, which is specifically expressed as formula (5).

[0079] (5)

[0080] Finally, based on the distance the reflected light travels in the experiment , the theoretical value of the composite multi-wavelength Goos-Hanchen shift can be obtained .

[0081] (6)

[0082] The Fresnel reflection coefficient Obtained by Fresnel multi-layer reflection formula. The following is an example of a sample with five layers of interface reflection. The reflection coefficients of more layers can be obtained by nesting in this way. Among them, the sample stage is a coupling prism, and the sample is tightly attached to the bottom surface of the coupling prism through the coupling liquid. The incident light is irradiated onto the sample through the coupling prism, and is totally reflected on the sample to generate reflected light.

[0083] When the light is incident at an angle θ i When medium 1 (for example, air) is incident on different interfaces of a sample (for example, the sample may include stacked medium 2, medium 3, medium 4 and medium 5), the reflection coefficient of the structure composed of the five layers of media can be obtained by the following formula:

[0084] (7)

[0085] (8)

[0086] (9)

[0087] (10)

[0088] For s-polarized incident light, r ij Obtained by the following formula

[0089] (11)

[0090] For p-polarized incident light, r ij Obtained by the following formula

[0091] (12)

[0092] For other polarized light, it can be decomposed into p-polarization component and S-polarization component, which can be calculated separately and then synthesized.

[0093] Where θ1 is the incident angle of light at the interface between the coupling prism and medium 1, θ i and θ j They represent the incident angle and refraction angle of the incident light from medium i to medium j respectively; λ is the wavelength of the incident light. i is the refractive index of medium i; D i is the thickness of medium i; k i and k j Respectively represent the vertical components of the propagation constants of incident light in medium i and medium j; r 12345 is the total reflection coefficient of the five-layer structure, r 2345 represents the reflection coefficient of light in the four-layer structure consisting of stacked medium 2 to medium 5, r 345 represents the reflection coefficient of light in the three-layer film structure composed of medium 3 to medium 5, r ij Represents the reflection coefficient of light at the interface between layer i and layer j.

[0094] As a second aspect of the present invention, a biochemical sensing method based on Goos-Hanchen shift measurement is also provided, including operation S100 to operation S400.

[0095] Operation S100, placing the sample 5 on the sample stage, and then placing the biochemical substance to be tested on the surface of the sample 5; wherein the sample stage 3 for placing the sample is selected as a coupling prism;

[0096] Operation S200, using the above detection method, the Goos-Hanchen shift at each wavelength before and after the biochemical substance to be tested is set on the surface of the sample 5 is tested to obtain the Goos-Hanchen shift change at each wavelength caused by the biochemical substance to be tested;

[0097] Operation S300, determining an optimal wavelength by comparing the Goos-Hanchen shift changes measured at various wavelengths, so that the Goos-Hanchen shift change corresponding to the optimal wavelength is the largest;

[0098] Operation S400, obtaining information of the biochemical substance to be tested by testing the Goos-Hanchen potential change at the optimal wavelength;

[0099] Among them, the information of biochemical substances includes concentration, thickness, refractive index, etc.

[0100] According to an embodiment of the present invention, when detecting biochemical substances, the biochemical substances to be tested are placed on the surface of the sample. The biochemical substances to be tested interact with the light field on the surface of the sample, thereby affecting the Goos-Hanchen shift of the sample. Therefore, by detecting the movement amount of the Goos-Hanchen shift caused by the biochemical substances to be tested before and after being set on the surface of the sample 5, the information of the biochemical substances to be tested can be obtained.

[0101] According to the embodiments of the present invention, a target wavelength with the best effect (the most obvious Goos-Hanchen shift) can be selected at any wavelength to detect biochemical substances, which can effectively improve the measurement accuracy.

[0102] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the following is a detailed description of the present invention in conjunction with the accompanying drawings. Figure 1 In these examples, an SPR chip with a 50 nm gold film is selected as a sample, and the sample is placed on a prism and a Kretschmann prism coupling structure is adopted.

[0103] Example 1

[0104] This example measures the multi-wavelength Goos-Hanchen shift generated by an SPR chip placed on a sample stage. The SPR chip is prepared by sputtering a 3 nm thick chromium film and a 50 nm thick gold film on a glass sheet.

[0105] In this example, the Goos-Hanchen shift of a sample placed on the sample stage at various wavelengths is measured as follows:

[0106] Step A: attach the SPR chip to be tested to the Kretschmann prism coupling structure, and fit the glass side of the SPR chip to be tested to the prism through the coupling liquid. Adjust the incident light to the p-polarization state through the polarizer to produce the SPR phenomenon. Then adjust the lens assembly so that the reflected light spot can be clearly imaged on the hyperspectral imaging module. Measure the distance that the reflected light propagates. .

[0107] Figure 3 The central area of ​​the hyperspectral image formed by the reflected light spot on the hyperspectral imaging module in Example 1 is shown.

[0108] like Figure 3The figure shows the central area of ​​the hyperspectral image of the surface plasmon resonance (SPR) chip measured at an incident angle of 45°. It can be found that there is an obvious color difference along the y direction, while the color difference in the x direction is not obvious, which indicates that the SPR chip has a wavelength-related Goos-Hanchen shift in the y direction. Among them, points A, B, and C are three pixel points in the hyperspectral image formed by the reflected light spot on the hyperspectral imaging module. Select points A, B, and C along the y direction to draw their spectral curves.

[0109] Figure 4 Shows Figure 3 Spectral curves of three pixel points.

[0110] like Figure 4 As shown, these are the spectral curves of the three pixels A, B, and C (the curve of light intensity changing with wavelength). Figure 4 It can be seen that the resonant wavelength of the SPR chip is 582.67nm.

[0111] Figure 5 Grayscale images of several specific wavelengths in Example 1 and the Goos-Hanchen shift corresponding to each grayscale image are shown.

[0112] like Figure 5 As shown, the Goos-Hanchen shifts obtained at three wavelengths in Example 1 are shown.

[0113] Select the resonance peak and one wavelength on each side of it, and the three wavelengths obtained are: 547.83nm, 582.67nm, 600.23nm, and then extract the corresponding three grayscale images from the measured hyperspectral image. Among them, part (a) is the grayscale image corresponding to the wavelength of 547.83nm, part (b) is the grayscale image corresponding to the wavelength of 547.83nm, and part (c) is the grayscale image corresponding to the wavelength of 547.83nm. Figure 5 It can be seen from part (a) that the light intensity of each pixel in the grayscale image at a wavelength of 547.83nm increases as y increases, so that the centroid of the light intensity is in the upper part of the grayscale image; Figure 5 In part (b), it can be seen that the light intensity of each pixel in the grayscale image at a wavelength of 600.23nm decreases as y increases, making the centroid of the light intensity in the lower part of the grayscale image; Figure 5 It can be seen from part (c) that the light intensity distribution of each pixel in the grayscale image at a wavelength of 582.67nm is relatively uniform, so that the centroid of the light intensity is in the middle of the grayscale image. Figure 5 It shows that there are opposite Goos-Hanchen shifts on both sides of the resonant wavelength of the sample.

[0114] Figure 6 A comparison between the simulation results and experimental results of the SPR chip is given.

[0115] like Figure 6 As shown, Figure 6 (a) is the comparison between the experimental spectrum and the simulated spectrum of pixel B in Example 1; Figure 6 (b) is the simulation result of the relationship between the phase and wavelength of the reflected light; Figure 6 (c) is the first-order approximation of the lateral Goos-Hanchen shift and the first-order approximation of the angular Goos-Hanchen shift obtained according to the Fresnel simulation formula; Figure 6 (d) is the simulation and experimental results of Goos-Hanchen shift.

[0116] from Figure 6 (a) It can be seen that the experimental spectrum and the simulated spectrum of pixel B in Example 1 are relatively close. The size of each pixel in the grayscale image in Example 1 The spot radius of the reflected light is equal to 150 pixels. The experimental and simulation results of the Goos-Hanchen shift in Example 1 are shown in Figure 6 As shown in (d), through Figure 6 (d) It can be seen that the experimental measurement results of the Goos-Hanchen shift are in high agreement with the simulation results.

[0117] The wavelength-resolved Goos-Hanchen shift measurement method provided in the embodiment of the present invention replaces the single-wavelength light source module and imaging device in the traditional Goos-Hanchen shift measurement with a white light source module suitable for multi-wavelengths and a hyperspectral microscope, so that a higher-throughput signal can be obtained, and the need for signal reference is reduced at the same time. At the same time, the method has low equipment cost, simple operation, and the theory involved in the simulation fitting is not complicated, which has very important practical significance for further research on Goos-Hanchen shift and sensing and characterization based on Goos-Hanchen shift.

[0118] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific 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 in the scope of protection of the present invention.

Claims

1. A wavelength-resolved Goos-Hanchen shift measurement method, the measurement method is implemented based on a hyperspectral imaging device, the hyperspectral imaging device includes a light source module, a hyperspectral imaging module, and a sample stage, the measurement method includes: The incident light from the light source module is irradiated onto the sample placed on the sample stage, and the incident light is reflected on the sample to obtain reflected light, wherein the incident light is a visible-near infrared polarized parallel light beam; wherein the sample is configured to enable the reflected light to produce a phase difference on the surface of the sample with respect to the incident light; The reflected light is received by the hyperspectral imaging module to obtain a hyperspectral image of the reflected light spot, and grayscale images of the reflected light spot at various wavelengths are extracted from the hyperspectral image, wherein each wavelength is in the visible-near infrared band; wherein each wavelength corresponds to a grayscale image; The Goos-Hanchen shift of the sample at each wavelength is obtained according to the distribution of light intensity with pixel position in the grayscale image at each wavelength.

2. The assay method according to claim 1, wherein The Goos-Hanchen shift of the sample at each wavelength is obtained according to the distribution of light intensity with pixel position in the grayscale image at each wavelength, including: According to the distribution of light intensity with pixel position in the grayscale image at each wavelength, the light intensity centroid of the reflected light spot corresponding to each wavelength is obtained; According to the displacement of the light intensity centroid relative to the target pixel in the grayscale image, the Goos-Hanchen shift of the sample at each wavelength is obtained.

3. The assay method according to claim 2, wherein The target pixel is the central pixel of the grayscale image of the reflected light spot.

4. The assay method according to claim 3, wherein The Goos-Hanchen shift is expressed as follows: in, Indicates wavelength The Goos-Hanchen shift under Indicates wavelength The coordinates of the center of mass of the light intensity under The wavelength The coordinates of any pixel in the grayscale image below, for The light intensity of the pixel, The direction is the direction of the component of the wave vector of the incident light on the surface of the sample, axis is perpendicular to the wave vector component, direction, direction and the normal direction of the sample surface ( direction) satisfies the right-hand screw rule, is the size of the pixel.

5. The assay method according to claim 1, wherein The sample stage includes: a displacement platform or a coupling prism.

6. The assay method according to claim 5, wherein When the sample stage is a coupled prism, the sample is a chip composed of a transparent substrate and one or more thin films deposited on the transparent substrate, and the sample includes an SPR chip, a PWR chip, a resonant mirror chip, a metasurface chip, and a photonic crystal chip; The sample is closely attached to the bottom surface of the coupling prism through the coupling liquid, and the incident light is irradiated onto the sample through the coupling prism and is totally reflected on the sample to generate the reflected light.

7. The measuring method according to claim 1, wherein The visible-near infrared linearly polarized parallel light beam is s-polarized light or p-polarized light or other linearly polarized light that can be decomposed into s-polarized components and p-polarized components.

8. The assay method according to claim 1, wherein The hyperspectral imaging device further comprises a lens assembly, The lens assembly is arranged between the sample and the hyperspectral imaging module. The reflected light passes through the lens assembly and is received by the hyperspectral imaging module to obtain a hyperspectral image of the reflected light spot magnified by the lens assembly.

9. A biochemical sensing method based on Goos-Hanchen shift assay, comprising: Placing the sample on the sample stage, and then placing the biochemical substance to be tested on the surface of the sample, wherein the sample stage for placing the sample is selected as a coupling prism; Using the detection method described in any one of claims 1 to 8, the Goos-Hanchen shift at each wavelength before and after the biochemical substance to be detected is placed on the surface of the sample is tested to obtain the Goos-Hanchen shift change at each wavelength caused by the biochemical substance to be detected; By comparing the Goos-Hanchen shift changes measured at various wavelengths, an optimal wavelength is determined so that the Goos-Hanchen shift change corresponding to the optimal wavelength is the largest; By testing the Goos-Hanchen potential change at the optimal wavelength, the information of the biochemical substance to be tested is obtained; The information of the biochemical substance to be tested includes concentration, thickness and refractive index.

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