Objective, optical imaging device, optical system, and optical system detection method

Abstract

The application discloses an objective lens, an optical imaging device, an optical system and an optical system detection method, relates to the field of optical detection, and aims to optimize the structure of the objective lens.The objective lens comprises a shell and an optical focusing assembly.The shell has an inner cavity, and the inner cavity has a first opening and a second opening.The optical focusing assembly is installed in the inner cavity, the focal point of the optical focusing assembly is located at the second opening, and the optical focusing assembly is configured to focus light entering the shell through the first opening at the focal point.The objective lens provided by the above technical scheme has the shell and the optical focusing assembly, the optical focusing assembly focuses light based on one of reflection principles and refraction principles, and the range of excitation angles can be large to meet the excitation requirements of different required samples.

Description

Technical Field

[0001] This invention relates to the field of optical spectroscopy, specifically to an objective lens, an optical imaging device, an optical system, and a method for detecting optical systems. Background Technology

[0002] Optical spectroscopy techniques, such as vibrational spectroscopy and fluorescence / photoluminescence spectroscopy, use optical systems to focus an excitation beam onto a sample region. By analyzing the changes in the frequency and intensity of scattered light (reflected or transmitted light) relative to the excitation light, the physicochemical properties of the sample can be determined. Optical spectroscopy detection techniques have advantages such as being non-destructive to samples, having low environmental requirements, high sensitivity, and being easy to integrate into existing analytical devices to achieve correlation functions, making them widely applicable in production and daily life.

[0003] Linear polarization-directed excitation of samples is the most common method in optical spectroscopy. For example, in food hygiene and public safety testing, the sample, after pretreatment, lies on a flat substrate surface. The microscopically numerous, randomly arranged sample molecules appear macroscopically uniformly distributed. This averaging effect reduces the sample's sensitivity to the incident angle and polarization state of the excitation light. However, when the sample exhibits a periodic arrangement or the sample quantity decreases, the polarization state and excitation angle of the excitation light gradually and significantly affect the spectrum, adversely impacting detection.

[0004] In related technologies, the polarization state and polarization angle of optical detection equipment are fixed. When the polarization state and polarization angle of the optical detection equipment exactly match the required polarization state and polarization angle of the sample, sample detection can be achieved. However, different samples have different characteristics, and therefore require different polarization states and polarization angles for the excitation light. Optical detection equipment in related technologies can only detect specific samples.

[0005] The inventors discovered that there is an urgent need in the industry to develop an optical spectrometer that can be used to detect a variety of samples with different characteristics. Summary of the Invention

[0006] This invention proposes an objective lens, an optical imaging device, an optical system, and a method for detecting the optical system, in order to optimize the structure of the objective lens.

[0007] Some embodiments of the present invention provide an objective lens, comprising:

[0008] A housing having an inner cavity having a first opening and a second opening; and

[0009] An optical focusing assembly is installed in the cavity, the focal point of the optical focusing assembly is located at the second opening, and the optical focusing assembly is configured such that light entering the housing through the first opening is focused at the focal point.

[0010] In some embodiments, the optical focusing component includes:

[0011] The lens group includes at least two lenses, wherein the excitation light is focused on the same point on the outside of the housing after passing through the lenses; or, the excitation light is focused on the same point on the plane where the second opening is located after passing through each of the lenses.

[0012] In some embodiments, the lenses of the lens group are arranged in a row and the concave surface of each lens faces the side where the focal point is located, and the refractive index of each lens gradually increases along the direction toward the focal point.

[0013] In some embodiments, the lens group includes at least one of the lenses, wherein at least one of the concave and convex surfaces is a quadratic surface.

[0014] In some embodiments, the optical focusing component includes:

[0015] The metal plate includes an arc surface; the metal plate is integral with the housing.

[0016] In some embodiments, the curve function of the arc surface satisfies the parabolic equation.

[0017] In some embodiments, the objective lens further includes:

[0018] A total internal reflection lens is mounted on the housing, and the center of the total internal reflection lens is located at the focal point of the optical focusing assembly.

[0019] In some embodiments, the total internal reflection lens includes a hemispherical prism, the convex surface of which is away from the focal point, the plane of which faces the focal point, and the plane of the total internal reflection lens is provided with an enhancement layer for exciting surface electromagnetic wave modes.

[0020] In some embodiments, the enhancement layer includes a first metal layer deposited on the plane of the total reflection lens or a two-dimensional material film layer prepared on the plane of the total reflection lens.

[0021] In some embodiments, the material of the first metal layer is selected from one or more of the following: gold, silver, copper, platinum, palladium; or, the material of the two-dimensional material film layer is selected from one or more of the following: graphene, boron nitride, transition metal chalcogenides, and heterojunctions composed of transition metal chalcogenides.

[0022] In some embodiments, the total internal reflection lens includes a hemispherical prism with its convex surface away from the focal point and its plane facing the focal point. The plane of the total internal reflection lens is deposited with a semi-reflective and semi-transparent film layer, which is configured such that some light is reflected and the rest is transmitted, to form surface total internal reflection on the surface of the semi-reflective and semi-transparent film layer away from the housing.

[0023] In some embodiments, the material of the semi-reflective and semi-transparent film layer is selected from one or more of the following: gold, silver, copper, aluminum, iron, platinum, palladium, and rhodium.

[0024] In some embodiments, the thickness of the semi-reflective and semi-transparent film layer is 5 nanometers to 50 nanometers.

[0025] In some embodiments, the total internal reflection lens is a hemispherical prism, the convex surface of the hemispherical prism is away from the side where the focal point is located, the plane of the hemispherical prism faces the side where the focal point is located, and a waveguide material layer is deposited on the plane of the total internal reflection lens.

[0026] In some embodiments, the waveguide material layer includes:

[0027] A second metal layer is deposited on the plane of the hemispherical prism; and

[0028] A waveguide dielectric layer is deposited on the surface of the second metal layer away from the hemispherical prism.

[0029] In some embodiments, the objective lens further includes:

[0030] A bracket is fixedly connected to the housing, and the total internal reflection lens is mounted on the housing via the bracket.

[0031] In some embodiments, the total internal reflection lens includes:

[0032] A first lens portion is fixedly or detachably connected to the housing; and

[0033] The second lens portion is detachably connected to the first lens portion, and the surface of the second lens portion away from the first lens portion is used to support the sample.

[0034] In some embodiments, the excitation angle of the optical focusing component is 0° to 85°.

[0035] In some embodiments, the coverage angle adjustment range of the optical focusing component is 0.5° to 5°.

[0036] In some embodiments, the aperture of the objective lens is 1.2 to 10 times that of the microscope objective lens.

[0037] Other embodiments of the present invention provide an optical imaging device, including the objective lens provided by any of the technical solutions of the present invention.

[0038] In some embodiments, the optical imaging device further includes:

[0039] A substrate, disposed outside the housing, is configured to hold the sample to be tested.

[0040] The substrate is constructed to be metallic, or a third metal layer or a two-dimensional material film layer is disposed on the side of the substrate facing the housing.

[0041] The material of the third metal layer is selected from one or more of the following: gold, silver, copper, platinum, palladium.

[0042] The material of the two-dimensional material film is selected from one or more of the following: graphene, boron nitride, transition metal chalcogenides, and heterostructures composed of transition metal chalcogenides.

[0043] In some embodiments, the focal point of the optical focusing component is located on the surface of the substrate.

[0044] In some embodiments, the substrate is located outside the focal point of the optical focusing assembly.

[0045] In some embodiments, the substrate is located outside the focal point of the optical focusing assembly, and micro / nanospheres for adjusting the spacing are sandwiched between the substrate and the total internal reflection lens of the optical focusing assembly.

[0046] In some embodiments, the optical imaging device further includes:

[0047] Nanoparticles are deposited on the substrate, and the nanoparticles are located in the focal region of the optical focusing component.

[0048] In some embodiments, the optical imaging device further includes:

[0049] A laser is constructed to emit laser light.

[0050] A beam expander is located upstream of the optical focusing assembly and downstream of the laser to expand the beam of light emitted by the laser.

[0051] In some embodiments, the optical imaging device further includes:

[0052] A beam converter includes a first conical lens and a second conical lens, the distance between the first conical lens and the second conical lens being adjustable; the first conical lens is located between the beam converter and the second conical lens, the first conical lens includes a concave conical surface, and the second conical lens includes a convex conical surface, the concave conical surface and the convex conical surface being disposed opposite to each other; wherein, the beam converter is configured to change the radius of light rays exiting through the beam expander.

[0053] In some embodiments, the optical imaging device further includes:

[0054] A polarizer includes a linear polarizer, a half-wave plate, and a vortex wave plate; the half-wave plate is located between the linear polarizer and the vortex wave plate; the polarizer is located between the beam converter and the housing, and the polarizer is configured to adjust the polarization state of light exiting the beam converter to one of the following: linear polarization, radial polarization, or angular polarization.

[0055] In some embodiments, the polarizer further includes:

[0056] The linear polarizer, the half-wave plate, and the vortex wave plate are all rotatably mounted on the support.

[0057] In some embodiments, the optical imaging device further includes:

[0058] The third reflecting mirror includes a dichroic mirror, which is located between the polarizer and the objective lens.

[0059] In some embodiments, the polarization direction of the light emitted from the half-wave plate coincides with the fast axis of the vortex wave plate, and the polarizer outputs radially polarized light.

[0060] In some embodiments, the polarization direction of the light emitted from the half-wave plate is perpendicular to the fast axis of the vortex wave plate, and the polarizer outputs angularly polarized light.

[0061] In some embodiments, the optical system includes one of the following: an optical slice microscope, a two-photon microscope.

[0062] Some embodiments of the present invention provide an optical system, including the optical imaging device provided by any of the technical solutions of the present invention.

[0063] In some embodiments, the optical system further includes:

[0064] Lighting equipment, configured to provide visible illumination; and / or

[0065] Spectroscopic detection equipment is configured to collect and analyze the scattered light from a sample under laser excitation.

[0066] In some embodiments, the lighting device includes:

[0067] Visible light sources are constructed to emit visible light;

[0068] A lens is disposed between the visible light source and the objective lens; and

[0069] An annular baffle is arranged between the lens and the objective lens.

[0070] In some embodiments, the lighting device further includes:

[0071] A first reflecting mirror is arranged between the annular baffle and the objective lens;

[0072] A semi-reflective, semi-transparent lens is arranged parallel to the reflecting surface of the first reflecting mirror;

[0073] The second mirror is movably disposed between the third mirror and the objective lens of the optical imaging device, and the second mirror is configured to switch between two positions: located in the optical path between the third mirror and the objective lens to reflect light from the visible light source into the objective lens, and located outside the optical path between the third mirror and the objective lens to avoid obstructing the propagation of light between the third mirror and the objective lens;

[0074] The first focusing lens is located on the side of the semi-reflective and semi-transparent lens away from the second reflecting mirror;

[0075] An imaging sensor is located on the side of the first focusing lens away from the semi-reflective, semi-transparent lens.

[0076] In some embodiments, the optical system further includes:

[0077] The microscope objective is configured to acquire the excitation image of the optical imaging device;

[0078] The illumination device includes two parts: a first illumination device and a second illumination device; the first illumination device is configured to provide illumination to the optical imaging device to enable the objective lens of the optical imaging device to focus, and the second illumination device is configured to provide illumination to the microscope objective lens to enable the microscope objective lens to focus.

[0079] In some embodiments, the optical system further includes an illumination device configured to provide visible illumination light; wherein the illumination device includes:

[0080] Visible light sources are constructed to emit visible light;

[0081] A lens is arranged between the visible light source and the objective lens;

[0082] An annular baffle is arranged between the lens and the objective lens;

[0083] A first reflecting mirror is arranged between the annular baffle and the objective lens;

[0084] A second reflecting mirror is movably disposed between the first reflecting mirror and the objective lens, and the second reflecting mirror is configured to switch between two positions: a third reflecting mirror located in the optical path between the first reflecting mirror and the objective lens to reflect light to the optical imaging device, and an external reflecting mirror located outside the optical path between the polarizer and the objective lens of the optical imaging device to avoid blocking the light output from the polarizer from reaching the third reflecting mirror;

[0085] A fluorescence microscope is positioned on the side of the third reflecting mirror away from the objective lens;

[0086] The first focusing lens is located on the side of the fluorescence microscope furthest from the third reflecting mirror; and

[0087] An imaging sensor is located on the side of the first focusing lens away from the fluorescence microscope.

[0088] In some embodiments, two sets of optical imaging devices are included, with the focal points of the two sets of optical imaging devices overlapping; and at least one set of optical imaging devices is mounted on a delay line so that the optical path difference of the laser emitted by the two sets of optical imaging devices is adjustable.

[0089] In some embodiments, the optical system further includes:

[0090] A beam combiner is configured to couple two excitation beams emitted from two sets of optical imaging devices into one beam.

[0091] Some embodiments of the present invention provide an optical system detection method, implemented using an optical system provided by any technical solution of the present invention, the optical system detection method comprising the following steps:

[0092] Turn on the illumination device and adjust the objective lens of the optical imaging device to achieve focus;

[0093] Adjust the polarization state, excitation angle, and coverage angle adjustment range of the laser path of the optical imaging device so that the characteristics of the excitation light meet the excitation requirements of the sample;

[0094] The sample was imaged and analyzed under laser excitation.

[0095] In some embodiments, the step of making the characteristics of the excitation light meet the excitation requirements of the sample includes the following steps:

[0096] Based on the excitation requirements of the sample, one of the following excitation modes is selected: Annular Vector Polarization Excitation Mode, Annular Vector Polarization Excitation Total Internal Reflection Mode, Annular Vector Polarization Excitation KR-SPP Mode, Annular Vector Polarization Excitation Otto-SPP Mode, Annular Vector Polarization Excitation Planar Waveguide Mode, Annular Vector Polarization Excitation Optical Slice Microscopy, and Annular Vector Polarization Excitation Slice Two-Photon Microscopy Mode.

[0097] In some embodiments, under the annular vector polarization excitation mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization, angular polarization, or linear polarization.

[0098] In some embodiments, in the annular vector polarization excitation total internal reflection mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization, angular polarization.

[0099] In some embodiments, in the ring vector polarization excitation KR-SPP mode, the polarization state of the excitation light is adjusted to radial polarization.

[0100] In some embodiments, in the Otto-SPP mode of annular vector polarization excitation, the polarization state of the excitation light is adjusted to radial polarization.

[0101] In some embodiments, under the annular vector polarization excitation planar waveguide mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization, angular polarization, or linear polarization.

[0102] In some embodiments, under an annular vector polarization excitation optical sectioning microscope, the excitation light state is adjusted to one of the following: radial polarization or angular polarization.

[0103] In some embodiments, in the annular vector polarization excitation slice two-photon microscope mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization, angular polarization.

[0104] The objective lens provided by the above technical solution has a housing and an optical focusing component. The optical focusing component achieves light focusing based on either the principle of reflection or the principle of refraction. The optical focusing component can achieve focusing within the range of 0° to 85° of the sample excitation angle, so it can be applied to different optical detection requirements and has a very wide range of applications. Attached Figure Description

[0105] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0106] Figure 1This is a schematic diagram of a refractive objective lens structure provided in some embodiments of the present invention;

[0107] Figure 2 This is a schematic diagram of a refractive objective lens structure provided in some other embodiments of the present invention;

[0108] Figure 3 A schematic diagram of a refractive objective lens with a total internal reflection lens provided for some embodiments of the present invention;

[0109] Figure 4a A schematic diagram of a total internal reflection lens with a first metal layer for a refractive objective lens with a reinforcing layer provided in some embodiments of the present invention;

[0110] Figure 4b for Figure 4a A magnified schematic diagram of the total internal reflection lens;

[0111] Figure 5a This is a schematic diagram illustrating the fixing of the total internal reflection lens of the objective lens provided in some embodiments of the present invention;

[0112] Figure 5b This is a schematic diagram illustrating the fixing of the total internal reflection lens of the objective lens provided in other embodiments of the present invention;

[0113] Figure 6a This is a schematic diagram of the structure of a refractive objective lens provided in some embodiments of the present invention;

[0114] Figure 6b for Figure 6a A magnified schematic diagram of the total internal reflection lens;

[0115] Figure 7a A schematic diagram of a refractive objective lens with a semi-transparent and semi-reflective layer provided in some embodiments of the present invention;

[0116] Figure 7b for Figure 7a A magnified schematic diagram of the total internal reflection lens;

[0117] Figure 8a A schematic diagram of a refractive objective lens structure with a waveguide layer provided for some embodiments of the present invention;

[0118] Figure 8b for Figure 8a A magnified schematic diagram of the total internal reflection lens;

[0119] Figure 9 This is a schematic diagram of a reflective objective lens structure provided in some embodiments of the present invention;

[0120] Figure 10 A schematic diagram of a reflective objective lens structure with a total internal reflection lens provided in some embodiments of the present invention;

[0121] Figure 11a This is a schematic diagram of an optical imaging device structure with a substrate, nanoparticles, and a reflective objective lens provided in some embodiments of the present invention;

[0122] Figure 11b This is a schematic diagram of an optical imaging device structure with a substrate, nanoparticles, and a refractive objective lens provided in some embodiments of the present invention;

[0123] Figure 12a This is a schematic diagram of an optical imaging device structure with a substrate, a probe, and a reflective objective lens, provided for some embodiments of the present invention.

[0124] Figure 12b This is a schematic diagram of an optical imaging device structure with a substrate, a probe, and a refractive objective lens provided in some embodiments of the present invention;

[0125] Figure 13a This is a schematic diagram of an optical imaging device structure in which a substrate and a total internal reflection lens are spaced apart, according to some embodiments of the present invention.

[0126] Figure 13b This is a schematic diagram of an optical imaging device structure in which a substrate and a total internal reflection lens are spaced apart, according to some embodiments of the present invention.

[0127] Figure 14a This is a schematic diagram of an optical imaging device structure in which a micro-nanosphere is sandwiched between a substrate and a total internal reflection lens, according to some embodiments of the present invention.

[0128] Figure 14b A schematic diagram of an optical imaging device with a refractive objective lens having micro-nanospheres sandwiched between a substrate and a total internal reflection lens, provided in some embodiments of the present invention;

[0129] Figure 15a A schematic diagram of an inverted optical imaging device with a reflective objective lens provided in some embodiments of the present invention;

[0130] Figure 15b A schematic diagram of an inverted optical imaging device with a refractive objective lens provided in some embodiments of the present invention;

[0131] Figure 16a A schematic diagram of an optical imaging device with a reflective objective lens having an enhancement layer on the substrate surface, provided in some embodiments of the present invention;

[0132] Figure 16b A schematic diagram of an optical imaging device with a refractive objective lens having a reinforcement layer on the substrate surface, provided in some embodiments of the present invention;

[0133] Figure 17This is a schematic diagram of the structure of an optical imaging device provided in some other embodiments of the present invention;

[0134] Figure 18 A schematic diagram illustrating the principle of a beam expander in an optical imaging device provided in some embodiments of the present invention;

[0135] Figure 19 A schematic diagram of the beam converter principle of an optical imaging device provided in some embodiments of the present invention;

[0136] Figure 20a A schematic diagram of the polarizer principle of an optical imaging device provided for some embodiments of the present invention;

[0137] Figure 20b Schematic diagrams of various waveplate structures of a polarizer in an optical imaging device provided in some embodiments of the present invention;

[0138] Figure 21a Schematic diagrams of optical system principles provided for some embodiments of the present invention;

[0139] Figure 21b To adopt Figure 21a The diagram shows a schematic of the optical detection process performed by the optical system in either annular vector polarization excitation particle or annular excitation enhanced probe mode.

[0140] Figure 22 A schematic diagram of the principle of the dichroic mirror in an optical imaging device provided in some embodiments of the present invention;

[0141] Figure 23 A flowchart illustrating the detection method under the annular vector polarization excitation total internal reflection mode provided in other embodiments of the present invention;

[0142] Figure 24 This is a flowchart illustrating the detection method in the ring vector polarization excitation KR-SPP mode provided in other embodiments of the present invention;

[0143] Figure 25 This is a flowchart illustrating the detection method in the Otto-SPP mode under the ring vector polarization excitation provided in other embodiments of the present invention;

[0144] Figure 26a This is a schematic diagram of the optical system principle for realizing the annular vector polarization excited planar waveguide mode according to other embodiments of the present invention;

[0145] Figure 26b This is a flowchart illustrating an optical detection method for annular vector polarization-excited planar waveguide modes provided in other embodiments of the present invention.

[0146] Figure 27aThis is a schematic diagram of the optical system principle for realizing the annular vector polarization excitation optical sectioning microscope mode, provided in some other embodiments of the present invention;

[0147] Figure 27b This is a flowchart illustrating the optical detection method for annular vector polarization-excited optical sectioning microscope mode provided in other embodiments of the present invention;

[0148] Figure 28a This is a schematic diagram of the optical system principle for realizing the annular vector polarization excitation optical sectioning microscope mode, provided in some other embodiments of the present invention;

[0149] Figure 28b This is a flowchart illustrating the optical detection method for annular vector polarization-excited optical section microscope mode provided in other embodiments of the present invention. Detailed Implementation

[0150] The following is combined Figures 1 to 28b The technical solution provided by this invention will be described in more detail below.

[0151] Explanation of nouns and terms used in this article.

[0152] Optical spectroscopy techniques, such as vibrational spectroscopy and fluorescence / photoluminescence spectroscopy, involve using an optical system to focus an excitation beam onto a sample region. By analyzing changes in the frequency and intensity of scattered light (reflected or transmitted light) relative to the excitation light, the physicochemical properties of the sample can be determined. Optical spectroscopy offers advantages such as non-destructive testing, low environmental requirements, high sensitivity, and ease of integration into existing analytical devices for correlation functions, making it widely applicable in production and daily life.

[0153] Polarization states include linear polarization, elliptic polarization, circular polarization, and vector polarization. Vector polarization includes radial polarization and angular polarization. In the field of optical spectroscopy, the main polarization states used are linear polarization, radial polarization, and angular polarization. The inventors discovered that the polarization state and excitation angle directly affect optical spectral properties. For example, in surface-enhanced Raman spectroscopy (SERS), optimizing the polarization state and excitation angle can achieve single-molecule level detection.

[0154] See Figure 1This invention provides an objective lens 100 suitable for optical spectral detection. The objective lens 100 includes a housing 1 and an optical focusing assembly 2. The housing 1 has an inner cavity 11, with a first opening 11a and a second opening 11b. The optical focusing assembly 2 is installed in the inner cavity 11, and its focal point is located at the second opening 11b. The focal point of the optical focusing assembly 2 can be located outside, inside, or on the plane containing the outermost part of the second opening 11b; all of these configurations can meet subsequent detection requirements. The optical focusing assembly 2 is configured such that light entering the housing 1 through the first opening 11a is focused at the focal point.

[0155] The inner diameters of the first opening 11a and the second opening 11b of the inner cavity 11 can be set according to the required adjustment of the excitation angle θ and the angle coverage range Δθ. The excitation angle θ refers to the angle between the beam centerline and the optical axis of the objective lens 100 after the beam passes through the optical focusing assembly 2. (See [reference]). Figure 1 , Figure 9 , Figure 14a As shown in the diagram. The so-called coverage angle adjustment range Δθ refers to the difference between the angle between the inner edge of the light ray and the optical axis M of the objective lens 100 and the angle between the outer edge of the light ray and the optical axis M of the objective lens 100 after the light ray passes through the optical focusing component 2. The inner diameter of the first opening 11a of the inner cavity 11 can be set much larger than that of commonly used microscope imaging objectives, i.e., microscope objectives 800. For example, the inner diameter of the inner cavity 11 is 1.2 to 10 times the inner diameter of the light aperture of the microscope objective lens 800, specifically 1.2 times, 1.4 times, 1.6 times, 3 times, 5 times, 6 times, 7 times, 8 times, 9 times, and 10 times.

[0156] The optical focusing assembly 2 can use the principles of reflection (the objective lens 100 has a parabolic reflective structure) and refraction (the objective lens 100 has a refractive structure) to focus light onto a set position outside the housing 1. These will be described in detail later.

[0157] In some embodiments, the excitation angle of the optical focusing component 2 is 0° to 85°. The excitation angle range of the optical focusing component 2 is particularly large, which can adapt to excitation light of various excitation angles and greatly improves the applicability of the objective lens 100.

[0158] In some embodiments, the coverage angle adjustment range Δθ of the optical focusing component 2 is 0.5° to 5°, see [link to documentation]. Figure 1 and Figure 9 As shown. Figure 9The positions of the excitation angle θ and the coverage angle adjustment range Δθ are displayed more clearly. The coverage angle range Δθ can be adjusted to a very small size, which allows for high precision adjustment of the excitation beam, even stepless adjustment. This enables precise adjustment of the excitation beam for various coverage angle adjustment ranges.

[0159] The optical focusing component 2 has multiple implementation methods, which will be categorized and described in detail later.

[0160] See Figure 1 In some embodiments, the optical focusing assembly 2 includes a lens group 21, which comprises at least two lenses. Multiple steps are provided inside the housing 1, and each lens is fixed to one of the steps. The focal point of the lens group 21 is focused at a point outside the housing 1. In these embodiments, the optical focusing assembly 2 focuses light using the principle of light refraction, and is therefore also referred to as a refractive objective lens 100. See also Figure 1 In embodiments where the optical focusing assembly 2 employs lens group 21, the aperture radius r' of the refractive objective 100 is greater than 20 mm, specifically, for example, 30 mm. In these embodiments without the total internal reflection lens 3 described later, the focal point of the optical focusing assembly 2 of the refractive objective 100 is located at the center of the concave surface of the fifth lens 215 described later. In the embodiments with the total internal reflection lens 3 described later, the refractive objective 100, in total internal reflection mode, can place the hemispherical prism within the space enclosed by the fifth lens 215 described later.

[0161] At this point, the excitation angle θ of the incident light exiting from the last lens (such as the fifth lens 215 in the five lens groups 21 described later, or the fourth lens 214 in the four lens groups 21) can reach a maximum of 80° through the lens group 21. The wall thickness d of the ring beam can be controlled to a minimum of 0.4 mm by the beam expander 300 and beam converter 400 described later. At this point, the excitation angle coverage Δθ of the outermost light rays focused on the sample does not exceed 2°, and the adjustment accuracy is very high.

[0162] See Figure 1 The lenses in lens group 21 are arranged in a row, and the concave surface of each lens faces the side where the focal point is located. Furthermore, along the direction towards the focal point, the refractive index of each lens gradually increases, and the Abbe numbers of each lens are complementary. Figure 1In the illustrated embodiment, the lens group 21 includes five lenses, which, along the direction of light incidence, are: a first lens 211, a second lens 212, a third lens 213, a fourth lens 214, and a fifth lens 215. The distance between the five lenses along the optical axis is set as needed. The first lens 211 has the lowest refractive index and the highest Abbe number. The fifth lens 215 has the highest refractive index and a lower Abbe number. In some embodiments, from the first lens 211 to the fifth lens 215, the refractive index increases from 1.4 to 1.9, and the Abbe number decreases from 70 to 25. By controlling the radii of curvature of the five lenses, the lens group 21 can possess excellent achromatic aberration capability. The above arrangement enables light to be effectively focused at a set focal point for subsequent optical detection.

[0163] See Figure 1 In some embodiments, the lens group 21 includes at least one lens, where at least one of its concave and convex surfaces is a quadratic surface. Specifically, all convex and concave surfaces can be quadratic surfaces to effectively reduce spherical aberration of the refractive objective lens 100. The quadratic surface satisfies the following formula:

[0164]

[0165] In the above formula (1), c is the reciprocal of the radius of curvature of the lens surface, h is the distance from a point on the lens surface to the vertex of the lens surface (i.e., the vertex of the surface on which the lens surface is located), and k is the quadratic surface constant.

[0166] See Figure 2 The following describes how lens group 21 uses four lenses.

[0167] exist Figure 2 In the illustrated configuration, lens group 21 comprises four lenses, which, along the direction of light incidence, are: first lens 211, second lens 212, third lens 213, and fourth lens 214. First lens 211 has the lowest refractive index, and fourth lens 214 has the highest refractive index. The refractive indices of first lens 211, second lens 212, third lens 213, and fourth lens 214 are 1.5–2, their Abbe numbers are 20–60, and their radii of curvature are 2–50. Lens group 21 uses four lenses, reducing the incident aperture and simplifying manufacturing. This arrangement effectively focuses light at a predetermined focal point for subsequent optical inspection.

[0168] The formula for the quadratic surface of lens group 21, which consists of four lenses, is as follows:

[0169]

[0170]

[0171] h 2 =x 2 +y 2 Formula (4)

[0172] In the above formulas (2) to (4), c is the reciprocal of the radius of curvature of the lens surface; k is the quadratic surface constant; h is the distance from a point on the surface to the vertex of the lens surface; x and y are the coordinates of a point on the surface relative to the vertex of the lens surface.

[0173] See Figures 3 to 4b In some embodiments, the objective lens 100 further includes a total internal reflection lens 3, which is mounted on the housing 1. The center of the total internal reflection lens 3 is located at the focal point of the optical focusing assembly 2. At the total internal reflection lens 3, light undergoes total internal reflection. In various embodiments with the total internal reflection lens 3, the planar distance between the surface of the sample 900 and the total internal reflection lens 3 is less than 20 micrometers.

[0174] See Figure 3 In some embodiments, the total internal reflection lens 3 includes a hemispherical prism, which may be an integral structure or a modular structure. The planar side of the hemispherical prism is located on the focal plane of the objective lens 100. The refractive index of the hemispherical prism ranges from 1.40 to 1.99. The above technical solution adds a total internal reflection lens 3, within which light undergoes total internal reflection, making it particularly suitable for products requiring optical inspection in total internal reflection mode.

[0175] The objective lens 100 provided in the various embodiments of the present invention can realize a ring vector polarization excited total internal reflection mode, which is particularly suitable for molecular-level optical detection where the size of the object to be detected is too small to be observed with the naked eye. The sample 900 to be detected is directly deposited or adsorbed onto the plane of the total internal reflection lens 3. When different samples need to be detected, the total internal reflection lens 3 is simply replaced. The optical detection method will be described in detail below in conjunction with the optical path in which the objective lens 100 is located.

[0176] See Figure 4a and Figure 4b In other embodiments, the total internal reflection lens 3 includes a first lens portion 31 and a second lens portion 32. The first lens portion 31 is fixedly or detachably connected to the housing 1. The second lens portion 32 is detachably connected to the first lens portion 31, and the surface of the second lens portion 32 away from the first lens portion 31 is used to mount the sample. After installation, the gap between the second lens portion 32 and the first lens portion 31 is filled with a refractive index coupling solution. The plane of the total internal reflection lens 3 is the surface of the second lens portion 32 away from the first lens portion 31. The arcuate surface of the total internal reflection lens 3 is the arcuate surface of the first lens portion 31 away from the second lens portion 32.

[0177] The objective lens 100 provided in the various embodiments of the present invention can realize the annular vector polarization excited total internal reflection mode, which is particularly suitable for molecular-level optical detection where the size of the object to be detected is too small to be observed with the naked eye. The sample 900 to be detected is directly deposited or adsorbed on the plane of the second lens section 32. When different samples need to be detected, the second lens section 32 can be directly replaced, which simplifies the detection operation. The optical detection method will be described in detail below in conjunction with the optical path in which the objective lens 100 is located.

[0178] See Figure 5a and Figure 5b In the embodiments described above, to facilitate the installation of the total internal reflection lens 3, the objective lens 100 also includes a bracket 7, which is fixedly connected to the housing 1. Specifically, this connection can be welded, glued, integrated, or detachable. Detachable connections include, for example, snap-fit ​​connections or threaded connections. The total internal reflection lens 3 is mounted on the bracket 7. Depending on the usage state, the position of the total internal reflection lens 3 varies... Figure 4b In the illustrated configuration, the total internal reflection lens 3 is located below the optical focusing assembly 2. In this case, the support 7 has a step, and the total internal reflection lens 3 is placed on this step, see [reference needed]. Figure 5a As shown below. Figure 15a and Figure 15b In the illustrated configuration, the total internal reflection lens 3 is positioned above the optical focusing assembly 2. At this time, the bracket 7 is provided with a step and a retaining part; the total internal reflection lens 3 is placed on the step and held in place by the retaining part, as shown. Figure 5b As shown.

[0179] During spectral detection, placing the sample at the focal point of objective lens 100 effectively excites the sample and generates the desired spectral signal. In total internal reflection mode, the sample is directly attached to the center of the hemispherical prism, with the center of the hemispherical prism coinciding with the focal point of objective lens 100. Alternatively, in total internal reflection mode, the sample can also be placed at a certain distance from the center of the total internal reflection lens 3, achieving relatively high excitation efficiency. The distance between the sample and the surface of the total internal reflection lens 3 is generally no more than 20 micrometers.

[0180] The technical solutions provided in the embodiments of this invention employ a total internal reflection lens 3 to improve the excitation efficiency of the excitation light, concentrating the energy of the excitation beam in a ring beam with extremely narrow walls. By controlling the beam polarization, the excitation angle and the excitation angle coverage range can be flexibly controlled according to the characteristics of the sample. This is particularly suitable for applications with special requirements for excitation angle and polarization, such as shell-isolated nanoparticle-enhanced spectroscopy, single-particle-enhanced spectroscopy, and probe-enhanced spectroscopy, and effectively improves the sensitivity of spectral detection. In addition, the above technical solutions reduce the angle control capability achieved by traditional large and complex angle-rotating devices to a highly integrated optical device, greatly simplifying the device structure and allowing direct application to existing microscopic spectroscopy systems.

[0181] See Figure 6a and Figure 6b The following describes some other embodiments of the objective lens 100, in which the objective lens 100 not only has a total reflection lens 3, but also an enhancement layer 4 to improve excitation efficiency.

[0182] See Figure 6a and Figure 6b In some embodiments, the total internal reflection lens 3 includes a hemispherical prism with its curved surface facing the housing 1, and an enhancement layer 4 is disposed on the plane of the total internal reflection lens 3. The enhancement layer 4 is used to excite surface electromagnetic wave modes.

[0183] The reinforcing layer 4 may be, for example, a first metal layer deposited on the plane of the total reflection lens 3 or a planar two-dimensional material film layer prepared on the total reflection lens 3.

[0184] In some embodiments, the material of the first metal layer is selected from one or more of the following: gold, silver, copper, platinum, and palladium. The first metal layer provides a support metal layer for the propagation of the surface electromagnetic field.

[0185] In other embodiments, the material of the two-dimensional material film is selected from one or more of the following: graphene, boron nitride, transition metal chalcogenides, and heterojunctions composed of transition metal chalcogenides. The thickness of the heterojunction is 0.2 nanometers to 50 nanometers. The two-dimensional material film provides a support material layer for the propagation of surface electromagnetic fields.

[0186] See Figure 7a and Figure 7b Depending on the different requirements of various optical inspections, in some embodiments, the total internal reflection lens 3 is a hemispherical prism. The convex surface of the hemispherical prism is away from the focal point, and the flat surface of the hemispherical prism faces the focal point. A semi-reflective and semi-transparent film layer 5 is deposited on the flat surface of the total internal reflection lens 3. The semi-reflective and semi-transparent film layer 5 is configured such that some light is reflected and the rest is transmitted, so as to form surface total internal reflection on the surface of the semi-reflective and semi-transparent film layer 5 away from the housing 1.

[0187] Referring to Figure 7, specifically, the material of the semi-reflective and semi-transparent film layer 5 is selected from one or more of the following: gold, silver, copper, aluminum, iron, platinum, palladium, and rhodium.

[0188] Referring to Figure 7, specifically, the thickness of the semi-reflective and semi-transparent film layer 5 is 5 nanometers to 50 nanometers.

[0189] See Figure 8a and Figure 8bIn other embodiments, objective lens 100 can implement a waveguide mode. Total internal reflection lens 3 employs a hemispherical prism, with the convex surface of the hemispherical prism away from the focal point and the flat surface of the hemispherical prism facing the focal point. A waveguide material layer 6 is deposited on the flat surface of total internal reflection lens 3.

[0190] See Figure 8a and Figure 8b The waveguide material layer 6 includes a second metal layer 61 and a waveguide dielectric layer 62. The second metal layer 61 is deposited on the plane of the hemispherical prism; the waveguide dielectric layer 62 is deposited on the side of the second metal layer 61 away from the hemispherical prism.

[0191] In waveguide mode, the second metal layer 61 is made of metals such as gold, silver, copper, aluminum, iron, platinum, palladium, and rhodium, with a thickness of 5 nanometers to 50 nanometers. The waveguide dielectric layer 62 is made of transparent dielectric materials in the visible and infrared wavelength ranges, such as silicon dioxide and its doped materials, alumina and its doped materials, zinc selenide and its doped materials, and cadmium sulfide and its doped materials. The thickness of the waveguide dielectric layer 62 is 50 nanometers to 30 micrometers.

[0192] See Figure 9 The following section introduces other implementation methods of the optical focusing component 2.

[0193] In some embodiments, the optical focusing component 2 includes a metal plate with an arc surface, and the metal plate is integral with the housing 1.

[0194] The metal plate is a sheet material with sufficiently low surface roughness, specifically a metallic mirror. Light is directly reflected by the metal plate and then focused at the focal point.

[0195] See Figure 9 In some embodiments, the curve function of the arc surface satisfies the parabolic equation. The focal point of objective lens 100 is located at the focal point of the parabolic surface of the metal plate.

[0196] The equation of the parabola is:

[0197] x 2 =2×p×y Formula (5)

[0198] Where the x-axis is the optical axis of objective lens 100, and the y-axis is perpendicular to the x-axis. p represents the distance from the focal point to the directrix, 2mm ≤ p ≤ 100mm. The focal position of the parabolic surface is... The focal plane is at position 160. The parabolic surface is the part where y>p / 2, and the beam of light incident along the axis is focused at the focal point after being reflected by the parabolic surface, with the incident angle ranging from 30° to 90°.

[0199] exist Figure 9In this system, the excitation angle θ is related to the radius r of the ring beam and is adjusted by the beam converter 400, which will be described later. The coverage range Δθ of the excitation angle is related to the wall thickness d of the ring beam and is adjusted by the beam expander 300. The polarization state of the ring beam can be adjusted by the polarizer 500 to one of the following: linear polarization, angular polarization, or radial polarization. For details on the adjustment methods of each component, please refer to the description in the optical system section below.

[0200] The relationships between p, r, d, θ and Δθ satisfy the following formulas (6) and (7):

[0201]

[0202]

[0203] In the above formulas (6) and (7), r is the radius of the ring beam and d is the wall thickness of the ring beam.

[0204] The relationships between p, r, d, θ and Δθ satisfy formulas (6) and (7), which are applicable to various embodiments of the optical focusing component 2 that achieve focusing using the principle of reflection or the principle of refraction.

[0205] The total internal reflection lens 3 and the various coatings disposed on the total internal reflection lens 3, as described above, also apply to the reflective objective lens 100. Examples are given below; for any points not explained, please refer to the section above regarding the refractive objective lens 100.

[0206] See Figure 10 The reflective objective lens 100 also includes a total internal reflection lens 3, which is at least partially located outside the housing 1, and the center of the total internal reflection lens 3 is located at the focal point of the optical focusing assembly 2. The center of the hemispherical prism coincides with the focal point of the parabolic surface.

[0207] The total internal reflection lens 3 can be a hemispherical prism, which can be a monolithic structure or a modular structure. With the total internal reflection lens 3 in place, light undergoes total internal reflection on one side of the plane of the lens 3, making it particularly suitable for scenarios requiring optical inspection in total internal reflection mode.

[0208] See Figure 10 The total internal reflection lens 3 is fixedly connected to the housing 1 via a bracket 7. The bracket 7 is annular, and the inner wall of the bracket 7 is provided with a boss 71 for supporting the total internal reflection lens 3, on which the total internal reflection lens 3 is placed.

[0209] See Figure 11a and Figure 11bOther embodiments of the present invention provide an optical imaging device 750, including an objective lens 100 provided by any of the technical solutions of the present invention. This optical imaging device 750 allows for independent setting of the excitation angle and polarization state for samples with different characteristics, and appropriate excitation angles and excitation polarization states can significantly improve the sensitivity of the optical spectrum.

[0210] The optical imaging device 750 can be any optical imaging device that requires the use of the objective lens 100, such as a spectrometer, microscope, etc.

[0211] See Figure 11a and Figure 11b In some embodiments, the optical imaging device 750 further includes a substrate 8 disposed outside the housing 1, the substrate 8 being configured to hold the sample 900 to be tested.

[0212] Regardless of whether the objective lens 100 is equipped with a total internal reflection lens 3, the substrate 8 can be provided. For example... Figure 11a As shown, without the total internal reflection lens 3, the substrate 8 is placed directly at the focal point of the objective lens 100, meaning the focal point of the light rays from the objective lens 100 is located on the upper surface of the substrate 8. The objective lens 100 can be a reflective type as described above. Figure 11a As shown, the transmission-type objective lens 100 Figure 11b As shown. The substrate 8 facilitates the placement, deposition, and preparation of the sample 900 to be tested.

[0213] See Figure 11a and Figure 11b In some embodiments, the substrate 8 carries nanoparticles 9 located in the focal region of the optical focusing assembly 2. The focal region refers to a small area centered on the focal point. The inclusion of nanoparticles effectively enhances excitation efficiency and improves optical detection performance.

[0214] The nanoparticles 9 located in the focal region are made of precious metals such as gold, silver, and copper, and their size ranges from 20 nanometers to 500 nanometers.

[0215] See Figure 12a and Figure 12b In some other embodiments, the objective lens 100 of the optical imaging device 750 does not have a total reflection lens 3, and the substrate 8 does not have nanoparticles 9. In this case, detection can be achieved by means of the excitation-enhanced spectral probe 12.

[0216] Figure 12aThe diagram shows a parabolic reflective objective lens 100. A schematic diagram of the relative positions of the focusing plane, substrate 8, and excitation enhancement spectral probe 12 of objective lens 100 is shown. The upper surface of substrate 8 coincides with the focusing plane. Sample 900 is a molecule, and the molecule to be measured is located on this plane. Excitation enhancement spectral probe 12 is placed at the focal point. The tip material of the excitation enhancement spectral probe 12 used in probe enhancement spectroscopy is a metal such as gold, silver, copper, aluminum, iron, platinum, palladium, or rhodium, with a tip radius of 5 nm to 1500 nm. After the excitation light passes through substrate 8, it excites the excitation enhancement spectral probe 12 at an angle θ. The sample scattered light signal originating from the focusing region is then collected by objective lens 100 and subsequently acquired and detected by a detection and analysis instrument. The detection and analysis instrument is, for example, a spectrometer 701. The excitation angle θ is controlled and adjusted by beam expander 300, which will be described later.

[0217] Figure 12b The diagram shows a refractive objective lens 100. A schematic diagram of the relative positions of the focusing plane, substrate 8, and excitation-enhanced spectroscopy probe 12 of objective lens 100 is shown. The upper surface of substrate 8 coincides with the focusing plane, the analyte molecule is located on this plane, and excitation-enhanced spectroscopy probe 12 is positioned at the focal point. Excitation light, after passing through the fifth lens 215, passes through substrate 8 and excites the excitation-enhanced spectroscopy probe 12 at an excitation angle θ. The specific excitation angle θ is controlled and adjusted by the beam expander 300, which will be described later.

[0218] See Figure 13a and Figure 13b , Figure 13a Objective 100 is a reflective objective 100. Figure 13b The objective lens 100 is a transmission type objective lens 100. The following describes an embodiment in which the substrate 8 and the total reflection lens 3 are spaced apart.

[0219] Specifically, the objective lens 100 of the optical imaging device 750 is provided with a total internal reflection lens 3, and the substrate 8 is disposed at a distance from the total internal reflection lens 3, with the substrate 8 located outside the focal point of the objective lens 100. The sample 900 to be tested is disposed on the surface of the substrate 8 facing the total internal reflection lens 3.

[0220] See Figure 14a and Figure 14b , Figure 14a Objective 100 is a reflective objective 100. Figure 14b The objective lens 100 is a transmission type objective lens 100. The following describes an embodiment in which the substrate 8 and the total reflection lens 3 are spaced apart, and micro / nanospheres 10 are sandwiched between them.

[0221] In other embodiments, the objective lens 100 of the optical imaging device 750 is provided with a total internal reflection lens 3, and a substrate 8 is spaced apart from the total internal reflection lens 3, with the substrate 8 located outside the focal point of the objective lens 100. Micro-nanospheres 10 are sandwiched between the substrate 8 and the total internal reflection lens 3. A sample is disposed on the surface of the substrate 8 facing the total internal reflection lens 3. The micro-nanospheres 10 are used to control the spacing between the substrate 8 and the total internal reflection lens 3.

[0222] See Figure 15a and Figure 15b , Figure 15a Objective 100 is a reflective objective 100. Figure 15b Objective 100 is a transmission objective 100. The following describes how to achieve an inverted objective.

[0223] Figure 15a The reflective objective lens structure described above is similar to the one in the previous text. Figure 10 The reflective objective lens in the same way has the same structure. Figure 15b The refractive objective lens structure in the text is the same as that described above. Figure 3 The refractive objective lenses have the same structure. The difference lies in the orientation of objective lens 100. Figure 3 and Figure 10 In the middle, the total internal reflection lens 3 is located below the housing 1. And... Figure 15a and Figure 15b In the middle, the total internal reflection lens 3 is located above the housing 1.

[0224] Figure 15a and Figure 15b In the diagram, the total internal reflection lens 3 is located above the housing 1. To clearly illustrate the waveguide material layer 6 disposed on the surface of the total internal reflection lens 3, a simplified drawing is used for the support 7.

[0225] See above for other places. Figure 3 and Figure 10 The details of that will not be repeated here.

[0226] See Figure 16a and Figure 16b In other embodiments, the substrate 8 is located outside the focal point of the optical focusing assembly 2. The sample 900 to be tested is located on the side of the substrate 8 facing the total internal reflection lens 3.

[0227] The substrate 8 can be made of metal or non-metal. If the substrate 8 is made of metal, the metal layer and the two-dimensional material film layer do not need to be formed on the surface of the substrate 8. If the substrate 8 is made of non-metal, optionally, a third metal layer 13 or a two-dimensional material film layer 14 is formed on the side of the substrate 8 facing the housing 1.

[0228] The material of the third metal layer 13 is selected from one or more of the following: gold, silver, copper, platinum, palladium.

[0229] The material of the two-dimensional material film 14 is selected from one or more of the following: graphene, boron nitride, transition metal chalcogenides, and heterostructures composed of transition metal chalcogenides.

[0230] The optical imaging device 750 provided by the above technical solution can be used in the optical slide microscope described later.

[0231] See Figure 17 In some embodiments, the optical imaging device 750 further includes a laser 200 and a beam expander 300. The laser 200 is configured to emit laser light. The beam expander 300 is located upstream of the optical focusing assembly 2 and downstream of the laser 200 to expand the beam of light emitted by the laser 200.

[0232] Laser 200 emits an excitation beam to excite the sample. The laser emitted by laser 200 is single-wavelength light, with a wavelength, for example, 325 nm to 1064 nm. The beam is single-mode TEM00, and the beam energy distribution satisfies the Gaussian equation. The beam is linearly polarized, with a polarization ratio of not less than 30:1. The beam diameter ranges from 1 mm to 3 mm.

[0233] See Figure 18 The beam expander 300 is used to increase the radius of the laser beam. The magnification of the beam expander 300 is determined by the performance of the objective lens 100, and the beam diameter magnification of the beam expander 300 is 1.5 to 10 times. The beam expander 300 includes a front lens 301 and a rear lens 302.

[0234] The beam expansion ratio of beam expander 300 satisfies the following formula (8):

[0235]

[0236] Where d is the beam radius after beam expansion, d' is the initial beam diameter, f is the focal length of the front lens 301, and f' is the focal length of the rear lens 302.

[0237] The laser emitted by laser 200, after passing through beam expander 300, becomes a solid laser. The radius of the solid laser is expanded to radius d by beam expander 300. The expanded excitation beam is then converted into a ring beam with radius r by beam converter 400. A ring beam is defined as a beam with a baffle or detector placed in front of it, resulting in a ring-shaped spot. The ring beam is converted into a ring-shaped vector-polarized beam by polarizer 500. The ring-shaped vector-polarized beam is then incident on objective lens 100 via third reflecting mirror 550. After passing through objective lens 100, the vector beam is focused in a cone shape at the focal plane (160°) onto the sample area. Beam converter 400 adjusts r, thereby adjusting the incident cone angle θ, and beam expander 300 adjusts d, thereby adjusting the coverage range Δθ of the incident cone angle, i.e., the coverage angle adjustment range Δθ. Depending on the sample characteristics, polarizer 500 is adjusted to select a suitable excitation light polarization state, and beam expander 300 and beam converter 400 are adjusted to adjust the excitation angle θ and the excitation angle coverage range Δθ. The excitation angle θ is adjustable within the range of 0–85°, offering a very wide range of adjustment and thus greatly expanding the applicable scenarios. The coverage angle adjustment range Δθ is 0.5°–5°, with a minimum adjustment amount of less than 1°, demonstrating very high adjustment precision. This technical solution has significant application value in optical spectroscopy fields related to excitation angle and polarization state, such as plasmon-enhanced spectroscopy and nano-infrared spectroscopy.

[0238] See Figure 17 and Figure 19 In some embodiments, the optical system further includes a beam converter 400, which includes a first conical lens 401 and a second conical lens 402, the distance between the first conical lens 401 and the second conical lens 402 being adjustable. For example, at least one of the first conical lens 401 and the second conical lens 402 can be made movable to facilitate adjustment of the distance between them. Figure 19 In the illustrated configuration, the second conical mirror 402 is movable along its own axial direction, i.e., movable in the optical path direction. The second conical mirror 402 is moved by a stepper motor 403 to adjust the distance between the first conical mirror 401 and the second conical mirror 402. The first conical mirror 401 is located between the beam converter 400 and the second conical mirror 402. The first conical mirror 401 includes a concave conical surface, and the second conical mirror 402 includes a convex conical surface. The concave and convex conical surfaces are arranged opposite to each other. The beam converter 400 is configured to change the radius of the light rays exiting through the beam expander 300.

[0239] The first conical mirror 401 and the second conical mirror 402 have the same refractive index, n. The cone angles of the first conical mirror 401 and the second conical mirror 402 are equal, α. A solid beam with radius d is converted into an annular beam with radius r after passing through beam converter 400. The edge thickness of the annular beam is d″. r and d″ satisfy the following formulas (9) and (10):

[0240]

[0241] d″=d formula (10)

[0242] Where L is the minimum axial distance between the first conical mirror 401 and the second conical mirror 402 along the optical axis of each conical mirror; by driving the second conical mirror 402 along the electric slide rail 404 via the stepper motor 403, the position of the second conical mirror 402 can be adjusted, thereby adjusting the size of the distance L between the first conical mirror 401 and the second conical mirror 402, and finally adjusting the radius r of the annular beam.

[0243] See Figure 17 , Figure 20a and Figure 20b In some embodiments, the optical imaging device 750 further includes a polarizer 500, which includes a linear polarizer 501, a half-wave plate 502, and a vortex wave plate 503. The half-wave plate 502 is located between the linear polarizer 501 and the vortex wave plate 503; the polarizer 500 is located between the beam converter 400 and the housing 1, and the polarizer 500 is configured such that light passing through the beam converter 400 becomes one of the following: linearly polarized light, radially polarized light, or angularly polarized light.

[0244] A waveplate has two principal axes: a fast axis and a slow axis. The refractive indices on these two axes are different, therefore the speeds of light on them are also different. When linearly polarized light is incident on a half-wave plate 502, and its polarization direction does not coincide with either the fast or slow axis, the outgoing light is still linearly polarized, but its polarization direction has rotated relative to the incident light. When circularly polarized light is incident on a half-wave plate 502, clockwise (counterclockwise) circularly polarized light will be converted into counterclockwise (clockwise) circularly polarized light.

[0245] A half-wave (λ / 2) plate is used to rotate the linear polarization direction of an incident beam. When mounted on a rotary mount, the half-wave plate 502 can be used as a continuously adjustable polarization rotator. Furthermore, when used in conjunction with a polarization beam splitter, it can be used as a variable-ratio beam splitter. The angle between the polarization direction of the outgoing light and the polarization direction of the incident light is twice the angle between the polarization direction of the incident light and the principal axis of the waveplate. The polarization direction remains unchanged when the polarization direction of the incident light coincides with the fast or slow axis.

[0246] The distance between the linear polarizer 501, the half-wave plate 502, and the vortex wave plate 503 is set as needed. The polarization state of the annular excitation light is adjusted by regulating the rotation angle between the linear polarizer 501, the half-wave plate 502, and the vortex wave plate 503.

[0247] Polarizer 500 converts a linearly polarized ring beam into a radially or angularly polarized beam. For example... Figure 20a and Figure 20bThe polarizer 500 structure is shown. A ring-shaped linearly polarized beam emitted from the laser 200 passes sequentially through a linear polarizer 501, a half-wave plate 502, and a vortex waveplate 503. The transmission polarization direction of the linear polarizer 501 is consistent with the polarization direction of the excitation light. By rotating the direction of the half-wave plate 502, the polarization direction of the excitation light can be adjusted. With a suitable polarization direction selected, the ring beam becomes a ring-shaped radially or angularly polarized beam after passing through the vortex waveplate 503.

[0248] To obtain linearly polarized light, polarizer 500 must satisfy the following relationship: when the fast axis of the half-wave plate is perpendicular to the fast axis of the vortex wave plate 503, and the angle between the fast axis of the half-wave plate 502 and the polarization direction of the linear polarizer 501 is β, the angle between the polarization direction of the outgoing light and the linear polarization direction is 2β.

[0249] To obtain radially polarized light, polarizer 500 satisfies the following relationship: the polarization direction of the linearly polarized beam after passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0250] To obtain angularly polarized light, the polarizer 500 satisfies the following relationship: when the polarization direction of the linearly polarized beam after passing through the half-wave plate (i.e., half-wave plate 502) is perpendicular to the fast axis of the vortex wave plate 503, the outgoing light is angularly polarized light.

[0251] See also Figure 17 , Figure 20a and Figure 20b The polarizer 500 also includes a support member 504. The linear polarizer 501, the half-wave plate 502, and the vortex wave plate 503 are all supported by the support member 504, and the half-wave plate 502 is rotatably mounted on the support member 504. Specifically, each wave plate can be rotatably mounted on a rotating cylinder 505, and the rotating cylinder 505 is rotatably mounted to the support member 504 by means of hinges or the like.

[0252] In some embodiments, the polarization direction of the light output from the half-wave plate 502 coincides with the fast axis of the vortex wave plate 503, and the polarizer 500 outputs radially polarized light.

[0253] In some embodiments, the polarization direction of the light output from the half-wave plate 502 is perpendicular to the fast axis of the vortex wave plate 503, and the polarizer 500 outputs angularly polarized light.

[0254] See Figures 21a to 22 Other embodiments of the present invention provide an optical system including the optical imaging device 750 provided by any of the technical solutions of the present invention. The sample 900 detected by this optical system can be in a gaseous environment or a liquid environment. Other embodiments of the detection method describe a sample 900 that can be in a gaseous environment or a liquid environment.

[0255] See Figure 21a and Figure 21b The optical system described in this embodiment is particularly suitable for annular vector polarization-excited nanoparticles and annular excitation-enhanced probes. Either nanoparticles or annular excitation-enhanced probes can be used. If the optical imaging device 750 uses annular excitation-enhanced probes, then it is annular vector polarization-excited annular excitation-enhanced probe. If nanoparticles 9 are disposed on the surface of the substrate 8 of the optical imaging device 750, then it is annular vector polarization-excited particles. For a detailed description of the objective lens 100 of the optical imaging device 750, please refer to the section above regarding... Figures 11a to 12b Introduction.

[0256] See Figure 21a The optical system includes an illumination device 600, an optical imaging device 750, and a spectral detection device 700.

[0257] See Figure 21a In some embodiments, the lighting device 600 includes a visible light source 601, a lens 602, and an annular baffle 603. If it is necessary to change the direction of light propagation, the lighting device 600 further includes a first reflector 604, a semi-reflective and semi-transparent lens 605, and a movable second reflector 606. The second reflector 606 moves along a direction perpendicular to its own plane to move light into and out of the light path as needed.

[0258] See Figure 21a Specifically, lens 602 is positioned between visible light source 601 and objective lens 100. An annular baffle 603 is positioned between lens 602 and objective lens 100. A first reflecting mirror 604 is positioned between annular baffle 603 and objective lens 100. A semi-reflective, semi-transparent lens 605 is arranged parallel to the reflecting surface of the first reflecting mirror 604. A second reflecting mirror 606 is movably positioned between the third reflecting mirror 550 and objective lens 100 of the optical imaging device 750, and is configured to switch between two positions: located in the optical path between the third reflecting mirror 550 and objective lens 100 to reflect light from visible light source 601 into objective lens 100; and located outside the optical path between the third reflecting mirror 550 and objective lens 100 to avoid obstructing the propagation of light between the third reflecting mirror 550 and objective lens 100. A first focusing mirror 607 is located on the side of the semi-reflective, semi-transparent lens 605 away from the second reflecting mirror 606. The imaging sensor 608 is located on the side of the first focusing lens 607 away from the semi-reflective and semi-transparent lens 605.

[0259] When light from the semi-reflective, semi-transparent lens 605 needs to be reflected into the objective lens 100, the second reflecting mirror 606 is located in the optical path between the third reflecting mirror 550 and the objective lens 100. It is understood that the optical path is reversible; when the optical path needs to be propagated in the reverse direction as described above, the second reflecting mirror 606 also needs to be moved into the optical path. When light from the objective lens 100 needs to be propagated into the spectral detection device 700, the second reflecting mirror 606 is moved out of the optical path between the third reflecting mirror 550 and the objective lens 100. The movement of the second reflecting mirror 606 is a linear reciprocating movement, which can be achieved by setting a linear reciprocating drive device, such as a linear motor. To improve the automation level of the equipment and the accuracy of movement control, displacement sensors, PLCs, and other control devices can also be set to achieve precise control of the displacement of the second reflecting mirror 606.

[0260] The specific optical path of the illumination device 600 during operation is described below: First, the second reflecting mirror 606 is moved into the optical path, and then the illumination device 600 is adjusted to operate. The wide-band visible light emitted by the visible light source 601 is converted into parallel light after passing through the lens 602, then becomes ring light after passing through the annular baffle 603, changes direction after passing through the first reflecting mirror 604, and then shines on the semi-reflective and semi-transparent lens 605. A portion of the light then illuminates the movable second reflecting mirror 606 and then enters the objective lens 100 of the optical imaging device 750. Figure 21a In the illustrated embodiment, the optical imaging device 750 includes a substrate 8, and the focal point of the objective lens 100 is located on the surface of the substrate 8. Therefore, when the visible light emitted by the illumination device 600 enters the objective lens 100, it will form a bright spot on the surface of the substrate 8. Focusing adjustment before detection is achieved by observing the bright spot.

[0261] See also Figure 21a The optical imaging device 750 includes the laser 200, beam expander 300, beam inverter 400, polarizer 500, and objective lens 100 described above. To facilitate the setting of the positional relationships of each component and the adjustment of the optical path direction, the optical imaging device 750 also includes a third reflecting mirror 550. The light emitted from the laser 200 of the optical imaging device 750 sequentially passes through the beam expander 300, beam inverter 400, polarizer 500, third reflecting mirror 550, and objective lens 100, and is focused onto the upper surface of the substrate 8 to excite the sample there. By adjusting the beam expander 300, beam inverter 400, and polarizer 500, the excitation light can be used to excite the sample 900 according to the required excitation angle θ, angle coverage range Δθ, and polarization state.

[0262] The spectroscopic detection device 700 collects the scattered light from the sample formed on the surface of the substrate 8 and uses it for subsequent optical detection and analysis. At this time, the second reflecting mirror 606 is located outside the optical path. The optical path sequence of the spectroscopic detection device 700 is as follows: the scattered light from the surface of the substrate 8 passes through the objective lens 100, then is transmitted to the third reflecting mirror 550. The dichroic mirror 550a of the third reflecting mirror 550 transmits the light to the filter 703, then it is focused by the second focusing mirror 702, and finally enters the spectrometer 701. See also... Figure 22 The third reflecting mirror 550 includes a dichroic mirror 550a, which can reflect the excitation light to the objective lens 100 at 45° with a reflectivity of over 98%, and can completely transmit the scattered light signals emitted from the sample 900 and the objective lens 100 with a transmission efficiency of over 75%.

[0263] It should be noted that, in this embodiment and in the following embodiments, the basic steps of the optical detection method include the following steps: adjusting the objective lens of the optical imaging device using the illumination device 600 to achieve focusing; adjusting the polarization state, excitation angle, and coverage angle adjustment range of the laser light path of the imaging device 750 so that the characteristics of the excitation light meet the excitation requirements of the sample; acquiring and analyzing the image of the sample under laser excitation. Depending on the specific detection requirements, the method of adjusting the excitation light will also differ. The specific details of each embodiment will be described in detail below. Where there is no contradiction, please refer to the detection process described in this paragraph.

[0264] See Figure 21b The following describes the first optical detection method implemented using the optical system provided in this embodiment: an optical detection method in the mode of annular vector polarization excited particles or nanoprobes. In this detection method, the objective lens 100 can be a parabolic reflector or a refractive objective lens 100. The objective lens 100 is applicable to both upright and inverted spectrometers.

[0265] Step S1100: Activate the white light illumination device 600 until a clear image of the nanoparticles or probe is observed on the imaging sensor 608.

[0266] In this step, the second reflecting mirror 606 is located in the optical path. The optical path of the illumination device 600 is as follows: the wide-band visible light emitted by the visible light source 601 of the illumination device 600 is converted into parallel light after passing through the lens 602, then becomes ring light after passing through the annular baffle 603, the first reflecting mirror 604, the semi-reflective and semi-transparent lens 605, and the movable second reflecting mirror 606 before entering the objective lens 100 of the optical imaging device 750. If the nanoparticles 9 are excited, the light is focused near the nanoparticles 9. If the probe is excited, the light is focused near the tip of the probe. The probe-enhanced spectroscopy method commonly uses an inverted spectrometer structure, and the excitation light polarization adopts a radial polarization state. The optical path of the illumination device 600 is also applicable to the various embodiments described below.

[0267] Taking nanoparticle 9 as an example: the light scattered by nanoparticle 9 is collected by objective lens 100, then passes through movable second reflecting mirror 606 and reflecting semi-transparent lens 605, then through first focusing lens 607, and finally imaged onto the surface of imaging sensor 608 by imaging lens. By observing the image, it is determined whether the sample is located at the focal point of objective lens 100.

[0268] In step S1200, the optical imaging device 750 and the spectral detection device 700 are activated, at which point the illumination device 600 is no longer active. The laser emitted by the optical imaging device 750 will illuminate the nanoparticle 9 region or the excitation-enhanced spectral probe 12 region at a high angle in a ring shape.

[0269] Step S1300: Adjust the angle coverage of the excitation light. Calculate the beam expansion ratio based on the required laser beam radius and select a beam expander 300 that meets the beam expansion ratio requirement. For example, if the laser beam radius is 0.25mm, and the beam expander 300 has a beam expansion ratio of 1.6, the output beam radius will be 0.4mm.

[0270] Step S1400: Adjust the excitation angle of the excitation beam. Specifically, by adjusting the position of the electric slide rail of the beam converter 400, the distance between the first conical mirror 401 and the second conical mirror 402 is changed, thereby adjusting the radius of the annular beam and thus the excitation angle.

[0271] Step S1500: Determine the polarization state of the excitation light and adjust the polarizer 500 so that the excitation light satisfies the required polarization state.

[0272] Specifically, based on the characteristics and target features of the sample 900 to be tested, the following settings are made:

[0273] Case 1: If the sample 900 to be tested has the best response to polarization perpendicular to the surface of the substrate 8, then radial polarization is used. In this case, the polarizer 500 is adjusted so that the polarization of the beam passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0274] Scenario 2: If the sample 900 to be tested has the best response to polarization on the surface of the parallel substrate 8, then angular polarization or linear polarization is used. In this case, the polarizer 500 is adjusted so that the polarization of the beam passing through the half-wave plate (i.e., half-wave plate 502) is perpendicular to the fast axis of the vortex wave plate 503.

[0275] The order in which steps S1300, S1400, and S1500 are executed is not limited.

[0276] Step S1600: Focus the collected sample signal from the nanoparticle or probe region into the spectrometer 701.

[0277] After the polarization state, excitation angle, and coverage angle range are determined in steps S1200 to S1600 above, the optical imaging device 750 can operate. The optical path of the optical imaging device 750 during operation is as follows: In this step, the second reflecting mirror 606 is located outside the optical path. The diameter of the excitation beam emitted by the laser 200 is increased to 2d by the beam expander 300. Subsequently, the beam converter 400 converts the beam with increased diameter into a ring beam with a beam wall thickness of d and a beam radius of r. The polarizer 500 can control the conversion of the polarization state of the ring beam between linear polarization and vector polarization, such as converting it to radial polarization. The third reflecting mirror 550 reflects the ring-polarized beam towards the objective lens 100, and then focuses it onto the surface of the substrate 8 with an excitation angle θ. At this time, the single nanoparticle 9 located on the surface of the substrate 8 is located at the center of the focal point. At this time, the single nanoparticle 9 will enhance the local electromagnetic field in the vicinity, improve the excitation efficiency of sample molecules in the local field, and amplify the spectral signal of molecular radiation to the far field in the local field. The spectral signal is converted into a parallel beam after passing through objective lens 100. The parallel beam is transmitted through third reflecting mirror 550 and then filtered out by filter 703, leaving only the signal light. The wavelength of the remaining signal light is focused by second focusing mirror 702 and then recorded in spectrometer 701.

[0278] Step S1700: Analyze the spectrum acquired by the spectrometer 701 to obtain the chemical composition of the sample.

[0279] The detection method provided by the above technical solution controls the excitation angle θ and the excitation angle coverage Δθ by the beam expander 300 and the beam converter 400, respectively, and controls the polarization of the excitation light by the polarizer 500. Therefore, it realizes the control of various vector polarization light fields such as arbitrary direction of linear polarization, angular polarization and radial polarization at the focusing plane.

[0280] See Figure 23 The second optical detection method is introduced below: the detection method in the annular vector polarization excited total internal reflection mode.

[0281] Before introducing the detection method, let's first describe the optical system upon which it is based. The optical system used in this detection method is the same as that described above. Figure 21a The optical systems used are basically the same, the difference being that the objective lens 100 in the optical system targeted by this detection method includes a total internal reflection lens 3. In other words, embodiments where the objective lens 100 includes a total internal reflection lens 3 are all suitable for ring vector polarization-excited total internal reflection mode. For the specific structure of the objective lens 100, please refer to the above section on... Figures 3 to 4b Introduction.

[0282] See Figure 23 The following describes how to use the optical system provided in this embodiment to achieve optical detection.

[0283] Step S2100: Activate the white light illumination device 600: Move the substrate 8 below the objective lens 100. When the substrate 8 is directly below the objective lens 100, a clear image of the sample surface can be observed on the surface of the substrate 8. A detailed description of the illumination device 600 is provided above and will not be repeated here.

[0284] In step S2200, the optical imaging device 750 and the spectral detection device 700 are activated, at which point the illumination device 600 is no longer active. The laser emitted by the optical imaging device 750 illuminates the nanoparticle 9 region or the excitation-enhanced spectral probe 12 region in a high-angle ring pattern.

[0285] Step S2300: Adjust the laser's angle coverage. Calculate the beam expansion ratio based on the required laser beam radius and select a beam expander 300 that meets the beam expansion ratio requirement. For example, if the laser beam radius is 0.25mm, and the beam expander 300 has a beam expansion ratio of 1.6, the output beam radius will be 0.4mm.

[0286] Step S2400: Adjust the excitation angle of the laser. Specifically, by adjusting the position of the electric slide rail of the beam converter 400, the distance between the first conical mirror 401 and the second conical mirror 402 is changed, the radius of the ring beam is adjusted, and thus the excitation angle is adjusted so that the excitation angle θ is greater than the critical angle for total internal reflection.

[0287] The plane of the hemispherical prism coincides with the focal plane of the parabolic reflecting objective 100, and the center of the prism coincides with the focal point of the parabolic mirror. At this point, the excitation angle θ and the excitation angle coverage range Δθ are adjusted to focus the incident light annularly onto the central region of the hemispherical prism. When the excitation angle θ is greater than the critical angle for total internal reflection, total internal reflection occurs in the central region of the hemispherical prism, generating an evanescent wave on the air side of the central region. Nanoparticles 9 and enhanced spectral probes within the evanescent wave range can enhance the local electromagnetic field strength, improving the excitation efficiency of sample molecules located in the local field. Higher excitation efficiency allows more excitation light energy to couple with the sample, improving the instrument's detection sensitivity.

[0288] Furthermore, in the detection method described in this embodiment, a total internal reflection lens 3 (i.e., a lens with a first metal layer and a two-dimensional material film layer on its surface) is selected. Figure 6a and Figure 6b The structure described above, compared to the scheme that only sets the total reflection lens 3, first excites surface electromagnetic waves on the surface of the first metal layer or two-dimensional material film. At this time, the laser energy will be further concentrated on the surface of the noble metal as the first metal layer or the graphene as the two-dimensional material film. Due to the generation of surface electromagnetic waves, a stronger and faster decaying evanescent wave is generated on the surface of the first metal layer or two-dimensional material film. This further increases the intensity of the local electromagnetic field of the nanoparticles 9 and the enhanced spectral probe within the range of the evanescent wave, thereby obtaining a higher excitation efficiency. The excitation efficiency can be increased by several times or even tens of times compared to the scheme that only sets the total reflection lens 3.

[0289] Step S2500: Determine the polarization state of the laser and adjust the polarizer 500 to ensure that the light meets the required polarization state.

[0290] Specifically, based on the characteristics and target features of the sample 900 to be tested, the following settings are made:

[0291] Case 1: If the sample has the best response to polarization perpendicular to the surface of substrate 8, radial polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0292] Scenario 2: If the sample has the best response to polarization on the surface of the parallel substrate 8, then angular polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) is perpendicular to the fast axis of the vortex wave plate 503.

[0293] The order in which steps S2300, S2400, and S2500 are executed is not limited.

[0294] In step S2600, the sample signal from the particle or probe region is collected and focused into the spectrometer 701.

[0295] Step S2700: Analyze the spectrum acquired by the spectrometer 701 to obtain the chemical composition of the sample.

[0296] As can be seen from the detection process described above, the general process of optical detection is the same regardless of whether there is a total internal reflection lens 3, but the excitation angle and polarization state may be different.

[0297] See Figure 24 The embodiments described above, which employ a total internal reflection lens 3 with an enhancement layer 4 on its surface (i.e., a first metal layer or a two-dimensional material film layer), are as follows: Figure 7a and Figure 7b The introduced structure enables a third type of optical detection: optical detection in the KR-SPP mode of annular vector polarization excitation. The KR-SPP mode refers to the detection mode used to realize the optical detection principle of exciting surface plasmons proposed by Kretschmann. The optical system used in this detection mode is a corresponding... Figure 21a The optical system. Please refer to the above introduction for details.

[0298] In this detection method, a thin film of metal or two-dimensional material supporting surface plasmon resonances (SPPs) is prepared on the surface of substrate 8, and the sample is placed on the film. The lower surface of substrate 8 is bonded to a hemispherical prism via a refractive index coupling fluid. At this point, a clear image of the sample on the surface of substrate 8 can be directly observed.

[0299] See Figure 24 The specific testing method is basically the same as the testing method described above, and includes the following steps:

[0300] Step S3100: Activate the white light illumination device 600 until a clear image of the sample surface is observed on the substrate 8. A detailed description of the illumination device 600 is provided above and will not be repeated here.

[0301] Step S3200: The optical imaging device 750 and the spectral detection device 700 are put into operation, at which time the illumination device 600 is no longer in use.

[0302] Step S3300: Adjust the laser excitation angle to achieve the SPP excitation angle. Specifically, by adjusting the position of the electric slide rail of the beam converter 400, the distance between the first conical mirror 401 and the second conical mirror 402 is changed, thereby adjusting the radius of the annular beam and thus adjusting the excitation angle to achieve the SPP excitation angle.

[0303] Step S3400: Determine the polarization state of the laser and adjust the polarizer 500 to make the light meet the required polarization state.

[0304] In this mode, the sample has the best response to polarization perpendicular to the surface of the substrate 8, so radial polarization is used. At this time, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0305] The order in which steps S3300 and S3400 are executed is not limited.

[0306] In step S3500, the scattered light signal from the sample in the particle or probe region is collected and focused into the spectrometer 701.

[0307] Step S3600: Analyze the spectrum acquired by the spectrometer 701 to obtain the chemical composition of sample 900.

[0308] The above detection methods are particularly suitable for the detection of ultrathin samples such as single molecules and single molecular layers.

[0309] See Figure 25 The following describes various embodiments of placing micro / nanospheres 10 between the total internal reflection lens 3 and the substrate 8 to achieve the fourth type of optical detection: optical detection in the ring vector polarization excitation Otto-SPP mode. The optical system used in this detection mode is corresponding to... Figure 21a The optical system. Please refer to the above introduction for details.

[0310] The Otto-SPP mode refers to a detection mode used to realize the optical detection principle of exciting surface plasmons proposed by Otto. The optical system upon which this detection method is based has a substrate 8 with a certain distance from the focal plane; the structure of the objective lens 100 used in this optical system is described above. Figure 7a , Figure 7b , Figure 14a , Figure 14b The structure is described. The excitation efficiency of this mode is also significantly higher than that of the microscope objective 800 in related technologies. In those techniques employing parabolic mirrors, the annular excitation light undergoes total internal reflection at the surface of a hemispherical prism, with the upper surface of the substrate 8 located within the evanescent field. The micro / nanospheres 10 control the spacing between the total internal reflection lens 3 and the substrate 8, placing the analyte molecule within the focusing region of the annular excitation light. The substrate 8 surface is deposited with a reinforcement layer 4, i.e., a first metal layer or a two-dimensional material film, such as... Figure 16a and Figure 16b When the excitation beam angle meets the surface plasmon excitation conditions, the local electromagnetic field intensity in the sample area on the substrate 8 surface can be further increased, resulting in higher excitation efficiency.

[0311] See Figure 25 The optical detection method in the ring vector polarization excitation Otto-SPP mode includes the following steps:

[0312] Step S4100: Activate the white light illumination device 600 until a clear image of the sample surface is observed on the substrate 8. A detailed description of the illumination device 600 is provided above and will not be repeated here.

[0313] In step S4200, the optical imaging device 750 and the spectral detection device 700 are put into operation, at which point the illumination device 600 is no longer in use.

[0314] Step S4300: Adjust the laser's angle coverage. Calculate the beam expansion ratio based on the required laser beam radius and select a beam expander 300 that meets the beam expansion ratio requirement. For example, if the laser beam radius is 0.25mm, and the beam expander 300 has a beam expansion ratio of 1.6, the output beam radius will be 0.4mm.

[0315] Step S4400: Adjust the laser excitation angle. Specifically, by adjusting the position of the electric slide rail of the beam converter 400, the distance between the first conical mirror 401 and the second conical mirror 402 is changed, thereby adjusting the radius of the ring beam and thus adjusting the excitation angle to achieve the SPP excitation angle.

[0316] Step S4500: Determine the polarization state of the laser and adjust the polarizer 500 to ensure that the light meets the required polarization state.

[0317] In this mode, the sample has the best response to polarization perpendicular to the surface of the substrate 8, so radial polarization is used. At this time, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0318] In step S4600, the sample signal from the region of nanoparticle 9 or excitation-enhanced spectral probe 12 is collected and focused into spectrometer 701.

[0319] Step S4700: Analyze the spectrum acquired by the spectrometer 701 to obtain the chemical composition of the sample.

[0320] Optical detection methods using the ring vector polarization excitation Otto-SPP mode are particularly suitable for detecting ultrathin samples such as single molecules and monolayers. Spectroscopic detection offers higher sensitivity, achieving detection sensitivity down to the single molecule level.

[0321] See Figure 26a and Figure 26b The following section describes optical detection in the annular vector polarization excited planar waveguide mode. The objective lens 100 shown in this detection mode is described above. Figure 8a and Figure 8b As introduced.

[0322] First, let's introduce the optical system structure on which this detection mode is based.

[0323] See Figure 26aIts optical system includes two illumination devices 600, one imaging device, and two spectral detection devices 700. The two illumination devices 600 are designated as first illumination device 600a and second illumination device 600b. The two spectral detection devices 700 are designated as first spectral detection device 700a and second spectral detection device 700b. The first illumination device 600a, the first spectral detection device 700a, and the optical imaging device 750 form a unified whole, working in conjunction with each other. The second illumination device 600b, the second spectral detection device 700b, and the microscope objective 800 form a unified whole, working in conjunction with each other. The focal points of the optical imaging device 750 and the microscope objective 800 coincide.

[0324] The first illumination device 600a has the same structure and function as the illumination device 600 described in the previous section on various optical systems. The second illumination device 600b has a structure that is basically the same as the illumination device 600 described above, except that it is used to illuminate the microscope objective 800. For the structure of the first illumination device 600a and the positional relationship between its components, please refer to the previous section; it will not be repeated here. Only the second illumination device 600b will be described.

[0325] See Figure 26a The second lighting device 600b includes a visible light source 601', a lens 602', and an annular baffle 603'. The visible light source 601' is configured to emit visible light; the lens 602' is arranged between the visible light source 601' and the microscope objective 800; the annular baffle 603 is arranged between the lens 602' and the microscope objective 800.

[0326] See Figure 26a The second illumination device 600b further includes a first reflecting mirror 604', a semi-reflective and semi-transparent lens 605', and a second reflecting mirror 606'. The first reflecting mirror 604' is arranged between the annular baffle 603' and the microscope objective 800. The semi-reflective and semi-transparent lens 605' is arranged parallel to the reflecting surface of the first reflecting mirror 604'. The second reflecting mirror 606' is movably arranged between the spectrometer 701 and the microscope objective 800, and the second reflecting mirror 606' is configured to switch between two positions: located in the optical path between the spectrometer 701 and the microscope objective 800 to reflect light from the visible light source 601' into the microscope objective 800, and located outside the optical path between the microscope objective 800 and the spectrometer 701, so as not to obstruct the propagation of light between the microscope objective 800 and the spectrometer 701. The first focusing lens 607' is located on the side of the semi-reflective and semi-transparent lens 605' away from the second reflecting lens 606'; the imaging sensor 608' is located on the side of the first focusing lens 607' away from the semi-reflective and semi-transparent lens 605'.

[0327] See also Figure 26aThe microscope objective 800 is equipped with a fourth reflecting mirror 801 and a fifth reflecting mirror 802 for changing the direction of light. In this detection mode, a waveguide material layer 6 is disposed on the surface of the substrate 8 of the objective 100, and the sample 900 to be detected is placed on the waveguide material layer 6. The lower surface of the substrate 8 is bonded to the hemispherical prism through a refractive index coupling fluid.

[0328] The optical detection method in the annular vector polarization excited planar waveguide mode includes the following steps:

[0329] Step S5100: Activate the first illumination device 600a and the second illumination device 600b until a clear image of the sample on the surface of the substrate 8 is directly observed.

[0330] The specific operating steps are as follows: move the second reflecting mirrors 606 and 606' into the optical path, and adjust the objective lens 100 and the microscope objective lens 800 so that the surface of the substrate 8 can be clearly seen on the imaging sensors 608 and 608'.

[0331] In step S5200, the optical imaging device 750 and the spectral detection device 700 are put into operation, at which point the illumination device 600 is no longer in use.

[0332] Specifically, the second reflectors 606 and 606' are moved out of the optical path. At this time, the laser emitted from the laser 200 is focused on the surface of the substrate 8 at a certain angle after beam expansion and shaping.

[0333] Step S5300: Adjust the laser excitation angle. Specifically, by adjusting the position of the electric slide rail of the beam converter 400, the distance between the first conical mirror 401 and the second conical mirror 402 is changed, the radius of the ring beam is adjusted, and thus the excitation angle is adjusted so that the excitation angle reaches the waveguide mode excitation angle.

[0334] When the excitation angle θ satisfies the excitation condition in the waveguide dielectric layer 62, an evanescent field is generated on the surface of the waveguide dielectric layer 62. The local electromagnetic field of the nanoparticles 9 or the enhanced spectral probe located within the evanescent field is further enhanced, thereby improving the excitation efficiency of the spectrum.

[0335] Step S5400: Determine the polarization state of the laser and adjust the polarizer 500 to make the laser meet the required polarization state.

[0336] Specifically, based on the characteristics and target features of the sample 900 to be tested, the following settings are made:

[0337] Case 1: If the sample has the best response to polarization perpendicular to the surface of substrate 8, radial polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0338] Scenario 2: If the sample has the best response to polarization on the surface of the parallel substrate 8, then angular polarization or linear polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) is perpendicular to the fast axis of the vortex wave plate 503.

[0339] By adjusting steps S5300 and S5400, the excitation angle and polarization state of the laser are made to meet the waveguide excitation conditions.

[0340] In step S5500, the sample signal from the nanoparticle 9 or the region of the excitation-enhanced spectral probe 12 is collected and focused into the spectrometer 701. The spectral signal originating from the substrate 8 is recorded by the spectrometer 701 after passing through the objective lens 100 and subsequent optical path. At the same time, another part of the spectral signal originating from the substrate 8 is recorded by the spectrometer 701' after passing through the microscope objective lens 800 and subsequent optical path.

[0341] Step S5600: Analyze the spectra acquired by spectrometers 701 and 701' to obtain the chemical composition of the sample.

[0342] The optical detection methods described above can be used with very small sample quantities and support a wider range of excitation angles and polarization modes, thus having a wider range of applications.

[0343] See Figure 27a and Figure 27b The following describes optical inspection in the ring vector polarization excitation optical section microscope mode. The objective lens 100 shown in this inspection mode is described above. Figure 8a and Figure 8b The content introduced.

[0344] In this mode, the optical system includes an illumination device 600 and an optical imaging device 750. See also Figure 27aThe illumination device 600 is configured to provide visible illumination light. The illumination device 600 includes a visible light source 601, a lens 602, an annular baffle 603, a first reflecting mirror 604, a second reflecting mirror 606, a first focusing mirror 607, an imaging sensor 608, and a fluorescence microscope 609. The visible light source 601 is configured to emit visible light. The lens 602 is disposed between the visible light source 601 and the objective lens 100. The annular baffle 603 is disposed between the lens 602 and the objective lens 100. The first reflecting mirror 604 is disposed between the annular baffle 603 and the objective lens 100. The second reflecting mirror 606 is movably disposed between the first reflecting mirror 604 and the objective lens 100, and is configured to switch between two positions: located in the optical path between the first reflecting mirror 604 and the objective lens 100 to reflect light to the third reflecting mirror 550 of the optical imaging device 750; and located outside the optical path between the polarizer 500 of the optical imaging device 750 and the objective lens 100 to avoid blocking the light output from the polarizer 500 from reaching the third reflecting mirror 550. A fluorescence microscope 609 is disposed on the side of the third reflecting mirror 550 away from the objective lens 100. A first focusing mirror 607 is located on the side of the fluorescence microscope 609 away from the third reflecting mirror 550. An imaging sensor 608 is located on the side of the first focusing mirror 607 away from the fluorescence microscope 609.

[0345] The following describes how to use the optical system provided in this embodiment to achieve optical detection.

[0346] Step S6100: Activate the white light illumination device 600, i.e., make the illumination device 600 function: Move the substrate 8 below the objective lens 100. When the substrate 8 is directly below the objective lens 100, a clear image of the sample surface can be observed on the substrate 8. The specific operation steps are as follows: Move the second reflecting mirror 606 into the optical path. The visible light source 601 emits broadband white light, which becomes parallel light after passing through the lens 602, then becomes ring light after passing through the annular baffle 603, and after passing through the first reflecting mirror 604, it is reflected by the second reflecting mirror 606 and the third reflecting mirror 550 before entering the objective lens 100, ultimately forming a light spot on the substrate 8. Move the sample or the objective lens 100 until the sample 900 is clearly visible.

[0347] Step S6200: Adjust the optical system so that both the optical imaging device 750 and the spectral detection device 700 are working, at which point the illumination device 600 is no longer functioning. Then, move the second reflecting mirror 606 out of the optical path.

[0348] Step S6300: Adjust the excitation angle. Specifically, by adjusting the position of the electric slide rail of the beam converter 400, the distance between the first conical lens 401 and the second conical lens 402 is changed, the radius of the annular beam is adjusted, and thus the excitation angle is adjusted so that the excitation angle reaches the maximum excitation angle that the objective lens 100 can tolerate.

[0349] Step S6400: Illuminate with optical imaging equipment 750, i.e., laser illumination.

[0350] Step S6500: Adjust the polarization state of the laser to switch between radial polarization and angular polarization to obtain fluorescence imaging of the sample under each polarization state.

[0351] Specifically, based on the characteristics and target features of the sample 900 to be tested, the following settings are made:

[0352] Case 1: If the sample has the best response to polarization perpendicular to the surface of substrate 8, radial polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0353] Scenario 2: If the sample has the best response to polarization on the surface of the parallel substrate 8, then angular polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) is perpendicular to the fast axis of the vortex wave plate 503.

[0354] Step S6600: Compare the imaging of sample 900 under different polarization states and analyze the internal structure of sample 900.

[0355] See Figure 28a and Figure 28b The optical inspection in the annular vector polarization excitation optical section microscope mode is described below. The objective lens 100 shown in this inspection mode is illustrated in Figure 8 above.

[0356] In this mode, the optical system, as described above, is designed for... Figure 27a The optical system includes at least one additional optical imaging device 750. Specifically, the optical system provided in this embodiment includes an illumination device 600, two optical imaging devices 750, and a spectral detection device 700. The two imaging devices converge light into a single path via a beam combiner 1000. The focal points of the two optical imaging devices 750 coincide; and at least one of the optical imaging devices 750 is mounted on a delay line 2000 so that the optical path difference of the laser emitted by the two optical imaging devices 750 is adjustable.

[0357] See Figure 28a and Figure 28b The optical section microscope includes two excitation beams, both of which are focused at the same point. The two excitation beams are combined using a beam combiner 1000. Specifically, the lasers emitted from objective lens 100, laser 200, beam expander 300, beam adjuster 400, and polarizer 500, along with the lasers emitted from objective lens 100', laser 200', beam expander 300', beam adjuster 400', and polarizer 500', are transmitted to objective lens 100 after passing through beam combiner 1000.

[0358] The following describes how to use the optical system provided in this embodiment to achieve optical detection.

[0359] Step S7100: Activate the white light illumination device 600, i.e., make the illumination device 600 function: Move the substrate 8 below the objective lens 100. When the substrate 8 is directly below the objective lens 100, a clear image of the sample surface can be observed on the surface of the substrate 8. The specific operating steps are as follows: Move the second reflecting mirror 606 into the optical path. The visible light source 601 emits broadband white light, which becomes parallel light after passing through the lens 602, then becomes ring light after passing through the annular baffle 603, and after passing through the first reflecting mirror 604, it is reflected by the second reflecting mirror 606 and the third reflecting mirror 550 before entering the objective lens 100. Move the sample or the position of the objective lens 100 until the sample is clearly visible.

[0360] In step S7200, both optical imaging devices 750 and the spectral detection device 700 are activated, at which point the illumination device 600 ceases to function. Then, the second reflecting mirror 606 is moved out of the optical path.

[0361] Step S7300: Adjust the excitation angle of each laser. Specifically, by adjusting the position of the electric slide rail of the beam converter 400, the distance between the first conical mirror 401 and the second conical mirror 402 is changed, the radius of the ring beam is adjusted, and thus the excitation angle is adjusted so that the excitation angle reaches the maximum excitation angle that the objective lens 100 can tolerate.

[0362] Step S7400: Use two-way laser illumination. Adjust the relative positions of the two lasers so that the path difference is 0 when the two beams converge at the beam combiner 1000.

[0363] Step S7500: Adjust the polarization state to switch between radial polarization and angular polarization to obtain fluorescence imaging of the sample under each polarization state.

[0364] Specifically, based on the characteristics and target features of the sample 900 to be tested, the following settings are made:

[0365] Case 1: If the sample has the best response to polarization perpendicular to the surface of substrate 8, radial polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) coincides with the fast axis of the vortex wave plate 503.

[0366] Scenario 2: If the sample has the best response to polarization on the surface of the parallel substrate 8, then angular polarization or linear polarization is used. In this case, the polarizer 500 is adjusted so that the linear polarization direction of the beam passing through the half-wave plate (i.e., half-wave plate 502) is perpendicular to the fast axis of the vortex wave plate 503.

[0367] The specific operations of steps S7300 to S7500 are as follows: At this time, the second reflecting mirror 660 has been moved out of the optical path. The two lasers 200 and 200' emit lasers respectively. After the beam and polarization state of the two lasers are adjusted, they are combined at the beam combiner 100, reflected by the third reflecting mirror 550, and enter the objective lens 100, where they are focused on the substrate 8. The delay device 2000 is adjusted to move the optical path difference between the left and lower optical arms at the beam combiner 100. When the optical path difference is 0, two-photon coupling will occur in the sample at the substrate 8. The fluorescent photons emitted from the sample pass through the objective lens 100, the dichroic mirror 550a, and the fluorescence filter 609, and are then focused by the imaging lens 607 onto the imaging sensor 608. By adjusting steps S7300 to S7500 during the above imaging process, different imaging effects can be obtained.

[0368] Step S7600: Compare the imaging of sample 900 under different polarization states and analyze the internal structure of sample 900.

[0369] Optical inspection in the annular vector polarization excitation optical sectioning microscope mode is mainly for life science samples such as cells and tissues.

[0370] The optical systems provided by the above-mentioned technical solutions limit the energy of the excitation light to within a 1-degree excitation angle range, significantly improving the light energy excitation efficiency; furthermore, the excitation angle is adjustable from 0 to 80 degrees, fully meeting the sample's requirements for the excitation angle; the polarization state is flexibly adjustable, fully meeting the sample's requirements for excitation polarization; and the optical system realizes the angle control capability achieved by traditional large and complex angle-rotating devices, which is reduced to an integrated optical imaging device 750, simplifying the device structure and allowing it to be combined with existing microspectral systems or developed into portable spectroscopic devices.

[0371] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only used to facilitate the description of this invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0372] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An objective lens, characterized in that, include: The housing (1) has an inner cavity (11) having a first opening (11a) and a second opening (11b). as well as An optical focusing assembly (2) is installed in the inner cavity (11), the focal point of the optical focusing assembly (2) is located at the second opening (11b), and the optical focusing assembly (2) is configured such that light entering the housing (1) through the first opening (11a) is focused at the focal point; The optical focusing component (2) includes: A lens group (21) includes at least two lenses, wherein at least one of the lenses has a concave surface and a convex surface that is a quadratic surface; wherein the excitation light is focused at the same point on the outside of the housing (1) after passing through the lens; or, the excitation light is focused at the same point on the plane where the second opening (11b) is located after passing through each of the lenses; or The optical focusing component (2) includes: The metal plate includes an arc surface, the curve function of which satisfies the parabolic equation; the metal plate and the shell (1) are integral; The optical focusing component (2) is configured to focus the sample within the range of 0° to 85°. The coverage angle adjustment range of the optical focusing component (2) is 0.5° to 5° to achieve precise adjustment of the excitation light within different coverage angle adjustment ranges.

2. The objective lens according to claim 1, characterized in that, Also includes: A total reflection lens (3) is mounted on the housing (1), and the center of the total reflection lens (3) is located at the focal point of the optical focusing assembly (2).

3. The objective lens according to claim 2, characterized in that, The total internal reflection lens (3) includes a hemispherical prism, the convex surface of which is away from the side where the focal point is located, and the plane of which is facing the side where the focal point is located. The plane of the total internal reflection lens (3) is provided with an enhancement layer (4) for exciting surface electromagnetic wave modes.

4. The objective lens according to claim 3, characterized in that, The enhancement layer (4) includes a first metal layer deposited on the plane of the total reflection lens (3) or a two-dimensional material film layer prepared on the plane of the total reflection lens (3).

5. The objective lens according to claim 4, characterized in that, The material of the first metal layer is selected from one or more of the following: gold, silver, copper, platinum, palladium; or The material of the two-dimensional material film is selected from one or more of the following: graphene, boron nitride, transition metal chalcogenides, and heterostructures composed of transition metal chalcogenides.

6. The objective lens according to claim 2, characterized in that, The total internal reflection lens (3) includes a hemispherical prism with its convex surface away from the focal point and its plane facing the focal point. A semi-reflective and semi-transparent film (5) is deposited on the plane of the total internal reflection lens (3). The semi-reflective and semi-transparent film (5) is configured such that some light is reflected and the rest is transmitted, so as to form surface total internal reflection on the surface of the semi-reflective and semi-transparent film (5) away from the housing (1).

7. The objective lens according to claim 6, characterized in that, The material of the semi-reflective and semi-transparent film layer (5) is selected from one or more of the following: gold, silver, copper, aluminum, iron, platinum, palladium, and rhodium.

8. The objective lens according to claim 7, characterized in that, The thickness of the semi-reflective and semi-transparent film layer (5) is 5 nanometers to 50 nanometers.

9. The objective lens according to claim 2, characterized in that, The total internal reflection lens (3) is a hemispherical prism, the convex surface of the hemispherical prism is away from the side where the focal point is located, the plane of the hemispherical prism faces the side where the focal point is located, and a waveguide material layer (6) is deposited on the plane of the total internal reflection lens (3).

10. The objective lens according to claim 9, characterized in that, The waveguide material layer (6) includes: A second metal layer (61) is deposited on the plane of the hemispherical prism; and A waveguide dielectric layer (62) is deposited on the surface of the second metal layer (61) away from the hemispherical prism.

11. The objective lens according to claim 2, characterized in that, Also includes: The bracket (7) is fixedly connected to the housing (1), and the total reflection lens (3) is mounted on the housing (1) through the bracket (7).

12. The objective lens according to claim 2, characterized in that, The total internal reflection lens (3) includes: The first lens portion (31) is fixedly or detachably connected to the housing (1); and The second lens portion (32) is detachably connected to the first lens portion (31), and the surface of the second lens portion (32) away from the first lens portion (31) is used to support the sample.

13. The objective lens according to any one of claims 1 to 12, characterized in that, The aperture of the objective lens is 1.2 to 10 times that of the microscope objective lens.

14. An optical imaging device, characterized in that, Includes the objective lens (100) as described in any one of claims 1 to 13.

15. The optical imaging device according to claim 14, characterized in that, Also includes: A substrate (8) is disposed outside the housing (1) and the substrate (8) is configured to hold the sample (900) to be tested.

16. The optical imaging device according to claim 15, characterized in that, The substrate (8) is constructed to be metallic.

17. The optical imaging device according to claim 15, characterized in that, The substrate (8) has a third metal layer or a two-dimensional material film layer on the side facing the housing (1).

18. The optical imaging device according to claim 17, characterized in that, The material of the third metal layer is selected from one or more of the following: gold, silver, copper, platinum, palladium.

19. The optical imaging device according to claim 17, characterized in that, The material of the two-dimensional material film is selected from one or more of the following: graphene, boron nitride, transition metal chalcogenides, and heterostructures composed of transition metal chalcogenides.

20. The optical imaging device according to claim 15, characterized in that, The focal point of the optical focusing component (2) is located on the surface of the substrate (8).

21. The optical imaging device according to claim 15, characterized in that, The substrate (8) is located outside the focal point of the optical focusing component (2).

22. The optical imaging device according to claim 21, characterized in that, The substrate (8) is located outside the focal point of the optical focusing component (2), and micro-nanospheres (10) for adjusting the spacing are sandwiched between the substrate (8) and the total reflection lens (3) of the optical focusing component (2).

23. The optical imaging device according to claim 15, characterized in that, Also includes: Nanoparticles (9) are deposited on the substrate (8) and are located in the focal region of the optical focusing component (2).

24. The optical imaging device according to any one of claims 14 to 23, characterized in that, Also includes: The laser (200) is configured to emit laser light; A beam expander (300) is located upstream of the optical focusing assembly (2) and downstream of the laser (200) to expand the beam of light emitted by the laser (200).

25. The optical imaging device according to claim 24, characterized in that, Also includes: A beam converter (400) includes a first conical lens (401) and a second conical lens (402), the distance between the first conical lens (401) and the second conical lens (402) being adjustable; the first conical lens (401) includes a concave conical surface, and the second conical lens (402) includes a convex conical surface, the concave conical surface and the convex conical surface being disposed opposite to each other; wherein the beam converter (400) is configured to change the radius of the light rays exiting through the beam expander (300).

26. The optical imaging device according to claim 25, characterized in that, Also includes: The polarizer (500) includes a linear polarizer (501), a half-wave plate (502), and a vortex wave plate (503); the half-wave plate (502) is located between the linear polarizer (501) and the vortex wave plate (503); the polarizer (500) is located between the beam converter (400) and the housing (1), and the polarizer (500) is configured to adjust the polarization state of the light emitted through the beam converter (400) to one of the following: linear polarization, radial polarization, or angular polarization.

27. The optical imaging device according to claim 26, characterized in that, The polarizer (500) further includes: The support member (504) is rotatably mounted on the linear polarizer (501), the half-wave plate (502) and the vortex wave plate (503).

28. The optical imaging device according to claim 26, characterized in that, Also includes: The third reflecting mirror (550) includes a dichroic mirror (550a) located between the polarizer (500) and the objective lens (100).

29. The optical imaging device according to claim 26, characterized in that, The polarization direction of the light emitted from the half-wave plate (502) coincides with the fast axis of the vortex wave plate (503), and the polarizer (500) outputs radially polarized light.

30. The optical imaging device according to claim 26, characterized in that, The polarization direction of the light emitted from the half-wave plate (502) is perpendicular to the fast axis of the vortex wave plate (503), and the polarizer (500) outputs angularly polarized light.

31. The optical imaging device according to claim 26, characterized in that, The optical imaging device includes one of the following: an optical slice microscope or a two-photon microscope.

32. An optical system, characterized in that, Includes the optical imaging device according to any one of claims 14 to 31.

33. The optical system according to claim 32, characterized in that, Also includes: The lighting device (600) is configured to provide visible illumination light; and / or The spectral detection device (700) is configured to collect and analyze the scattered light of the sample (900) under laser excitation.

34. The optical system according to claim 33, characterized in that, The lighting device (600) includes: The visible light source (601) is configured to emit visible light; Lens (602), disposed between the visible light source (601) and the objective lens (100); and An annular baffle (603) is arranged between the lens (602) and the objective lens (100).

35. The optical system according to claim 34, characterized in that, The lighting device (600) also includes: A first reflecting mirror (604) is arranged between the annular baffle (603) and the objective lens (100); A semi-reflective and semi-transparent lens (605) is arranged parallel to the reflecting surface of the first reflector (604); The second mirror (606) is movably disposed between the third mirror (550) and the objective lens (100) of the optical imaging device (750), and the second mirror (606) is configured to switch between two positions: located in the optical path between the third mirror (550) and the objective lens (100) to reflect light from the visible light source (601) into the objective lens (100), and located outside the optical path between the third mirror (550) and the objective lens (100) to avoid obstructing the propagation of light between the third mirror (550) and the objective lens (100); The first focusing lens (607) is located on the side of the semi-reflective and semi-transparent lens (605) away from the second reflecting mirror (606); An imaging sensor (608) is located on the side of the first focusing lens (607) away from the semi-reflective and semi-transparent lens (605).

36. The optical system according to claim 33, characterized in that, Also includes: The microscope objective (800) is configured to acquire the excitation image of the optical imaging device (750); The illumination device (600) includes two parts: a first illumination device (600a) and a second illumination device (600b); the first illumination device (600a) is configured to provide illumination to the optical imaging device (750) to enable the objective lens (100) of the optical imaging device (750) to be focused, and the second illumination device (600b) is configured to provide illumination to the microscope objective lens (800) to enable the microscope objective lens (800) to be focused.

37. The optical system according to claim 32, characterized in that, It also includes a lighting device (600) configured to provide visible illumination; wherein the lighting device (600) includes: The visible light source (601) is configured to emit visible light; A lens (602) is arranged between the visible light source (601) and the objective lens (100); An annular baffle (603) is arranged between the lens (602) and the objective lens (100); A first reflecting mirror (604) is arranged between the annular baffle (603) and the objective lens (100); The second mirror (606) is movably disposed between the first mirror (604) and the objective lens (100), and the second mirror (606) is configured to switch between two positions: a third mirror (550) located in the optical path between the first mirror (604) and the objective lens (100) to reflect light to the optical imaging device (750); and an external optical path located between the polarizer (500) of the optical imaging device (750) and the objective lens (100) to avoid blocking the light output from the polarizer (500) from reaching the third mirror (550). A fluorescence microscope (609) is arranged on the side of the third reflecting mirror (550) away from the objective lens (100); The first focusing lens (607) is located on the side of the fluorescence microscope (609) away from the third reflecting mirror (550); and An imaging sensor (608) is located on the side of the first focusing lens (607) away from the fluorescence microscope (609).

38. The optical system according to claim 37, characterized in that, It includes two sets of optical imaging devices (750) with their focal points overlapping; and at least one set of optical imaging devices (750) is mounted on a delay line (2000) so that the optical path difference of the lasers emitted by the two sets of optical imaging devices (750) is adjustable.

39. The optical system according to claim 38, characterized in that, Also includes: The beam coupler (1000) is configured to couple two excitation beams emitted by the two optical imaging devices (750) into one beam.

40. A detection method for an optical system, characterized in that, The optical system described in any one of claims 32 to 39 is used to implement the detection method of the optical system, which includes the following steps: Turn on the illumination device and adjust the objective lens of the optical imaging device to achieve focus; Adjust the polarization state, excitation angle, and coverage angle adjustment range of the laser path of the optical imaging device so that the characteristics of the excitation light meet the excitation requirements of the sample; The sample was imaged and analyzed under laser excitation.

41. The optical system detection method according to claim 40, characterized in that, The process of ensuring that the characteristics of the excitation light meet the excitation requirements of the sample includes the following steps: Based on the excitation requirements of the sample, one of the following excitation modes is selected: Annular Vector Polarization Excitation Mode, Annular Vector Polarization Excitation Total Internal Reflection Mode, Annular Vector Polarization Excitation KR-SPP Mode, Annular Vector Polarization Excitation Otto-SPP Mode, Annular Vector Polarization Excitation Planar Waveguide Mode, Annular Vector Polarization Excitation Optical Slice Microscopy, and Annular Vector Polarization Excitation Slice Two-Photon Microscopy Mode.

42. The optical system detection method according to claim 41, characterized in that, In the annular vector polarization excitation mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization, angular polarization, or linear polarization.

43. The optical system detection method according to claim 41, characterized in that, In the annular vector polarization excitation total internal reflection mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization or angular polarization.

44. The optical system detection method according to claim 41, characterized in that, In the KR-SPP mode of annular vector polarization excitation, the polarization state of the excitation light is adjusted to radial polarization.

45. The optical system detection method according to claim 41, characterized in that, In the Otto-SPP mode of annular vector polarization excitation, the polarization state of the excitation light is adjusted to radial polarization.

46. ​​The optical system detection method according to claim 41, characterized in that, In the annular vector polarization excitation planar waveguide mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization, angular polarization, or linear polarization.

47. The optical system detection method according to claim 41, characterized in that, Under an annular vector polarization excitation optical section microscope, the excitation light state is adjusted to one of the following: radial polarization or angular polarization.

48. The optical system detection method according to claim 41, characterized in that, In the annular vector polarization excitation section two-photon microscope mode, the polarization state of the excitation light is adjusted to one of the following: radial polarization or angular polarization.

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