Light film forming apparatus and light film forming method

Abstract

This application discloses a method and apparatus for generating light sheets. The apparatus, along the direction of light propagation, sequentially includes: a light source module having a laser for generating a laser beam; a polarization state pre-adjustment module configured to collimate and rotate the polarization direction of the laser beam; a Wollaston prism, wherein a laser beam whose polarization direction is rotated by the polarization state pre-adjustment module to form a 45° angle with the optical axis of the Wollaston prism is incident on the Wollaston prism, so that two beams of light are emitted from the Wollaston prism; a one-dimensional shaping module; a polarization adjustment and optical path compensation module; a dual-mirror synchronous scanning module; and an objective lens.

Description

Technical Field

[0001] This application broadly relates to the fields of biomedical photonics and microscopic imaging technology, and particularly to a method and apparatus for generating high-quality illumination sheets using a Wollaston prism for physical beam splitting combined with interferometry. Specifically, this application relates to a method and apparatus for generating ultrathin illumination sheets based on Wollaston prism beam splitting interferometry, primarily applied to high spatiotemporal resolution three-dimensional fluorescence imaging of live biological samples, observation of dynamic processes in cell biology, and long-term embryo imaging in developmental biology. Background Technology

[0002] As life science research delves deeper into the microscopic and dynamic realms, higher demands are placed on microscopic imaging techniques. Light-Sheet Fluorescence Microscopy (LSFM), with its unique orthogonal illumination and detection methods, naturally possesses advantages such as low phototoxicity, low photobleaching, and rapid three-dimensional imaging, making it the preferred tool for studying the developmental processes of model organisms like zebrafish and nematodes, as well as the fine internal structures of cells. In a light-sheet microscopy system, the quality of the illumination slide—especially its thickness, uniformity, and diffraction-free propagation distance—directly determines the system's axial resolution, optical sectioning capability, and effective imaging field of view.

[0003] In existing technologies, lattice light-sheet microscopy (LLS) has emerged to achieve axial resolution exceeding that of traditional Gaussian light-sheets. Currently, the mainstream and almost sole universal method for generating lattice light-sheets is to use a spatial light modulator (SLM) to modulate the phase or amplitude of a laser wavefront. As a programmable diffractive optical element, the SLM generates a specific light field distribution at the back focal plane of the objective lens by loading a computer-generated hologram, and then forms a Bessel lattice light-sheet at the sample through Fourier transform.

[0004] However, although SLM-based light sheet generation technology has been applied to some extent in scientific research, its inherent physical defects and technical bottlenecks are becoming increasingly prominent in the process of practical engineering and the pursuit of ultimate imaging quality. These are mainly reflected in the following aspects: First, the pixelated structure leads to uneven illumination and ghosting effects. SLMs are essentially composed of millions of discrete liquid crystal pixel units, equivalent to a two-dimensional grating. When a laser beam illuminates the SLM surface, in addition to generating the required diffracted beam (component), higher-order diffracted beams (components) are inevitably generated. These parasitic higher-order diffracted beams (components), after passing through a Fourier transform lens, are superimposed on the main sheet in the form of periodic side lobes, resulting in significant periodic intensity ripples (ghost images) and grating artifacts in the cross-section of the illumination field. This non-uniform illumination not only severely reduces the signal-to-noise ratio of the image but also introduces difficult-to-correct systematic errors in light sheet microscopy for subsequent image deconvolution processing and quantitative fluorescence intensity analysis.

[0005] Secondly, the fill factor of the device limits the improvement of axial resolution. Due to the limitations of micro-nano fabrication technology, there are opaque or uncontrollable gaps between SLM pixels, and their fill factor is usually around 90%. This leads to significant zero-order light leakage, that is, some light energy is reflected directly without modulation. In order to block this stray light, a spatial filter (i.e., a mask) must be introduced into the optical path. This not only reduces energy utilization, but more importantly, it limits the effective numerical aperture (NA) that the light sheet microscope system can utilize. Currently, the effective NA of commercial SLM systems is usually difficult to reach the limit of the objective lens, resulting in the generated light sheet thickness often being limited to 3-4µm or more, making it difficult to break through the 2µm physical barrier, and thus failing to meet the super-resolution observation requirements of subcellular microstructures (such as mitochondrial cristae and microtubule networks).

[0006] Furthermore, the architecture of a light sheet microscope system based on SLM is extremely complex and suffers from poor environmental stability. To function with the SLM, multiple 4F relay lens systems need to be connected in series in the optical path to achieve pupil plane relay, and a precisely adjusted polarizing beam splitter (PBS) and half-wave plate are required. This complex optical path design results in an extremely long optical axis (often exceeding 1 meter) and dozens of optical elements in the light sheet microscope system. The excessive number of optical surfaces not only introduces aberration accumulation and light energy loss but also makes the light sheet microscope system extremely sensitive to environmental vibrations and temperature drift. Even minor mechanical creep or air disturbances can cause alignment deviations between the phase map and the pupil, leading to a drastic deterioration in the light sheet quality and requiring frequent and complex calibration and maintenance by professionals.

[0007] Finally, dispersion effects limit multicolor simultaneous imaging. SLMs are diffractive devices with strong wavelength-dependent modulation characteristics. During multicolor fluorescence imaging, excitation light of different wavelengths undergoes dispersion shifts in diffraction angle and focal length after passing through the SLM, causing different colors of the light sheet to not coincide in optical axis position and thickness. Although compensation can be achieved by loading different phase maps, this requires the light sheet microscope's imaging system to employ a time-division exposure mode, significantly sacrificing imaging speed and making it difficult to capture fast-moving biological processes.

[0008] In summary, existing SLM-based optical sheet generation schemes have significant drawbacks in terms of uniformity, ultrathin thickness acquisition, system stability, and multicolor imaging. Therefore, there is an urgent need to develop a novel optical sheet generation method and apparatus that abandons pixelated modulation devices and utilizes physical optics principles to directly generate highly uniform, ultrathin, and structurally stable optical sheets. Summary of the Invention

[0009] In view of the above-mentioned defects and deficiencies in the existing technology, this application provides a method and apparatus for generating ultrathin optical sheets based on Wollaston prism beam splitting interference.

[0010] According to one aspect of this application, a light sheet generating apparatus is provided, which comprises, in sequence along the direction of light propagation: A light source module, which has a laser that generates a laser beam; A polarization state pre-adjustment module is configured to collimate and rotate the polarization direction of the laser beam; A Wollaston prism, wherein a laser beam whose polarization direction is rotated by the polarization state pre-tuning module to form a 45° angle with the optical axis of the Wollaston prism is incident on the Wollaston prism, and two beams of light are emitted from the Wollaston prism; A one-dimensional shaping module is configured such that the two beams of light are shaped into two linear beams after passing through the one-dimensional shaping module; A polarization adjustment and optical path compensation module has a half-wave plate arranged in the optical path of one of the two linear beams, so that the polarization direction of the linear beam in the optical path is rotated to be consistent with the polarization direction of the other linear beam. The polarization adjustment and optical path compensation module also has a glass plate arranged in the optical path of the other linear beam to ensure that the optical paths of the two optical paths are consistent. A dual-mirror synchronous scanning module includes a first galvanometer and a second galvanometer, the first galvanometer being configured to selectively scan the two linear beams in a first direction, the second galvanometer being configured to selectively scan the two linear beams in a second direction perpendicular to the first direction; and an objective lens.

[0011] In one embodiment, the polarization state pre-adjustment module includes a collimating lens and a first half-wave plate sequentially along the direction of light propagation. The collimating lens collimates the laser beam, and the first half-wave plate rotates the polarization direction of the laser beam to 45° with the optical axis of the Wollaston prism.

[0012] In one embodiment, the light sheet generating apparatus further includes a separation angle control module, which includes a beam expanding lens group consisting of a first lens and a second lens located upstream of the Wollaston prism; and a beam contracting lens group consisting of a third lens and a fourth lens located downstream of the Wollaston prism.

[0013] In one embodiment, the first lens and the second lens are arranged in a 4F system between the collimating lens and the first half-wave plate; and the third lens and the fourth lens are arranged in a 4F system between the Wollaston prism and the one-dimensional shaping module.

[0014] In one embodiment, the one-dimensional shaping module includes a cylindrical lens, the first galvanometer is located at the conjugate plane downstream of the cylindrical lens, and the generatrix direction of the cylindrical lens is parallel to the rotation axis direction of the first galvanometer.

[0015] In one embodiment, the dual-galvanometer synchronous scanning system further includes a scanning lens and a tube lens, which are arranged between the second galvanometer and the objective lens in a manner that forms a 4F system.

[0016] In one embodiment, the dual-mirror synchronous scanning system further includes a fifth lens and a sixth lens, which are arranged between the first and second galvanometers in a manner that forms a 4F system.

[0017] In one embodiment, the Wollaston prism is made of synthetic quartz material, and its apex angle is [missing information]. The initial beam splitting angle for a wavelength of 633nm is .

[0018] In one embodiment, the glass plate is a temperature-controlled glass plate, so that the temperature is maintained at a predetermined value during operation of the light sheet generating apparatus.

[0019] In one embodiment, at least one of the first lens, the second lens, the third lens, and the fourth lens is capable of one-dimensional micro-displacement within a range of ±100µm.

[0020] According to another aspect of this application, a method for generating a light sheet is also provided, comprising: The laser beam is collimated and its polarization direction is rotated so that the polarization direction of the laser beam is at 45° to the optical axis of the Wollaston prism and is incident on the Wollaston prism. The two beams of light emitted from the Wollaston prism will be shaped into two linear beams; A half-wave plate is arranged in the optical path of one of the two linear beams so that the polarization direction of the linear beam in that optical path is rotated to be consistent with the polarization direction of the other linear beam. A glass plate is arranged in the optical path of the other linear beam to ensure that the optical path lengths of the two optical paths are consistent. Two linear beams are passed through a first galvanometer, a second galvanometer, and an objective lens. The first galvanometer is configured to selectively scan the two linear beams in a first direction, and the second galvanometer is configured to selectively scan the two linear beams in a second direction perpendicular to the first direction.

[0021] In one embodiment, collimation of the laser beam is achieved using a collimating lens, and rotation of the polarization direction of the laser beam is achieved using a first half-wave plate.

[0022] In one embodiment, the method for generating the light sheet further includes: A beam-expanding lens group consisting of a first lens and a second lens is arranged upstream of the Wollaston prism; and Downstream of the Wollaston prism, a beam-constricting lens group consisting of a third lens and a fourth lens is arranged.

[0023] In one embodiment, a cylindrical lens is used to shape two beams of light emitted from the Wollaston prism into two linear beams. The first galvanometer is located at the conjugate plane downstream of the cylindrical lens, and the generatrix direction of the cylindrical lens is parallel to the rotation axis direction of the first galvanometer.

[0024] In one embodiment, the first lens and the second lens are arranged in a 4F system between the collimating lens and the first half-wave plate; and the third lens and the fourth lens are arranged in a 4F system between the Wollaston prism and the cylindrical lens.

[0025] In one embodiment, the scanning lens and the tube lens are arranged between the second galvanometer and the objective lens in a manner that forms a 4F system.

[0026] In one embodiment, the light sheet generation method further includes arranging a fifth lens and a sixth lens in a manner that forms a 4F system between the first galvanometer and the second galvanometer.

[0027] In one embodiment, the Wollaston prism is made of synthetic quartz material, and its apex angle is [missing information]. The initial beam splitting angle for a wavelength of 633nm is .

[0028] In one embodiment, the glass plate is a temperature-controlled glass plate, so that the temperature is maintained at a predetermined value during operation.

[0029] In one embodiment, at least one of the first lens, the second lens, the third lens, and the fourth lens is capable of one-dimensional micro-displacement within a range of ±100µm.

[0030] The technical approach of this application solves the problem of uneven light sheet generation in existing SLM-based light sheet generation schemes. By utilizing the physical birefringence properties of a Wollaston prism for continuous wavefront beam splitting, replacing the discrete pixel modulation of SLM, the periodic intensity ripples caused by high-order diffraction beams (components) and pixel gaps are eliminated from a physical perspective, achieving high-quality illumination with continuous and uniform cross-sectional intensity distribution. Furthermore, the technical approach of this application overcomes the axial resolution bottleneck of optical microscopy systems: through precise beam-expanding and beam-contracting lens group design, combined with a small-angle beam-splitting prism (Wollaston prism), the edge aperture of high numerical aperture (NA 0.8-1.1) objectives can be maximized to generate an ultrathin light sheet with a full width at half maximum (FWHM) ≤ 2µm, significantly improving the axial resolution and optical tomography capabilities of the imaging. The technical approach of this application can also improve the environmental stability of optical microscopy systems. This application employs a temperature-controlled optical path compensation mechanism—a temperature-controlled glass plate is placed in one of the two line beams to fine-tune the optical path difference, providing closed-loop compensation for phase jitter caused by ambient temperature drift or mechanical vibration, ensuring the long-term stability of the interference fringes. The technical approach of this application simplifies the architecture of optical microscopy systems and reduces costs. Because expensive and complex SLM devices and their associated complex relay optical paths can be eliminated, and standard optical lenses, prisms, and waveplates are used to construct the optical microscopy system, the number of optical components can be significantly reduced, lowering assembly difficulty and hardware costs. Attached Figure Description

[0031] A more comprehensive understanding of the principles and aspects of this application will be gained from the detailed description below, in conjunction with the accompanying drawings. It should be noted that the scale of the drawings may vary for clarity, but this will not affect the understanding of this application. In the drawings: Figure 1 This schematically illustrates the optical path diagram of a structured light super-resolution illumination micro-imaging optical system according to the prior art; Figure 2 The diagram illustrates the optical path of a structured light super-resolution illumination microscopic imaging optical system according to an embodiment of this application. Detailed Implementation

[0032] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0033] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; other experimental methods and technical means not specifically mentioned herein refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0034] The terms “basic” and “approximately” as used herein are used to describe small fluctuations. For example, they can mean less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. Numerical data presented or expressed in range format herein are used for convenience and brevity only, and should therefore be interpreted flexibly to include not only the explicitly listed values ​​that define the range, but also all independent values ​​or subranges contained within that range. For example, a numerical range of “1–5%” should be interpreted to include not only the explicitly listed values ​​from 1% to 5%, but also the independent values ​​and subranges within the indicated range. Thus, this numerical range includes independent values ​​such as 2%, 3.5%, and 4%, and subranges such as 1%–3%, 2%–4%, and 3%–5%, etc. This principle also applies to ranges that list only one value. Furthermore, this interpretation applies regardless of the width of the range or the characteristics described.

[0035] In this document, including in the claims, conjunctions such as "comprising," "including," "with," "having," "containing," "involving," and "accommodating" are understood to be open-ended, meaning "including but not limited to." Only the conjunctions "consisting of" and "composed of" are closed conjunctions.

[0036] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail in order to highlight the main points of this application.

[0037] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the content disclosed in the embodiments of this application. It should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this application indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing technical features and simplifying 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 limitations on this application unless they conflict with the context. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance unless they conflict with the context.

[0038] The specific embodiments of this application are described below to enable those skilled in the art to understand this application. However, it should be understood that this application is not limited to the scope of the specific embodiments. For those skilled in the art, as long as the various changes are within the spirit and scope of this application as defined and determined by the appended claims, these changes are obvious. All applications that utilize the concept of this application are protected.

[0039] In the accompanying drawings of this application, features with the same structure or similar function are indicated by the same reference numerals.

[0040] Figure 1 The diagram schematically illustrates the optical path of a structured light super-resolution illumination microscopy system according to the prior art. The super-resolution light-sheet microscopy system mainly includes a light source module 100, a light sheet generation and phase adjustment module 200, an objective lens 400, and a fluorescence detection module 500. When the structured light super-resolution illumination microscopy system is in operation, the light source module 100 outputs a single or multiple wavelength laser beam that is incident on the light sheet generation and phase adjustment module 200. The light sheet generation and phase adjustment module 200 thereby generates two light sheets with a predetermined spatial relationship. These two light sheets illuminate a biological sample placed on the stage (not shown) of the structured light super-resolution illumination microscopy system via the objective lens 400. During this process, the two light sheets interfere at the plane where the biological sample is located, forming structured light with fringes to illuminate the biological sample. Simultaneously, the fluorescence excited by the irradiated biological sample passes through another objective lens (…). Figure 1 and 2(Not shown in the image) is received as part of the fluorescence detection module 500 and collected by the fluorescence detection module 500. Since the excited fluorescence signal carries super-resolution information generated by structured light irradiation, the entire biological sample is scanned with structured light by moving the biological sample along a pre-defined path. With the help of post-processing algorithms, two-dimensional or three-dimensional super-resolution light sheet microscopy can be finally achieved.

[0041] The light source module 100 may include one or more lasers. For example, each laser may emit laser light of a different wavelength. For example, available lasers may include 405 nm, 445 nm, 488 nm, 561 nm, 640 nm wavelength lasers, etc. For example, in the case where the light source module 100 includes multiple lasers, each laser may be equipped with a corresponding lens group, so that the laser light emitted from each laser can be expanded into parallel light of equal diameter by the corresponding lens group, and the parallel light of equal diameter from different lasers can be combined into a single laser beam using a reflector and a dichroic mirror (or beam splitter). In addition, this laser beam may pass through an acoustic-optical tunable filter before output to selectively ensure that light of a specific wavelength passes through and to control the power of the output light.

[0042] Those skilled in the art will understand that the description of the optical system only shows or illustrates those essential optical components necessary to achieve the basic core concept of the technical solution of this application. For example, in Figure 1 In the image, the light generation and phase adjustment module 200 mainly includes a spatial light modulator (SLM), a half-wave plate (HWP), a polarizing beam splitter (PBS), and a mask. Of course, although not shown, those skilled in the art should understand that... Figure 1In the optical path shown, a pair of cylindrical lenses (not shown) can be arranged in the optical path section between the spatial light modulator (SLM) and the light source module 100 to form a beam-expanding optical module, so that the incident parallel light from the light source module 100 is stretched in one dimension and emitted as rectangular parallel light. The spatial light modulator (SLM), the half-wave plate (HWP), and the polarizing beam splitter (PBS) are arranged to form a phase grating, so that the expanded laser beam generates multiple positive and negative light components after passing through the phase grating. Specifically, the spatial light modulator (SLM), the half-wave plate (HWP), and the polarizing beam splitter (PBS) are arranged so that the laser beam input from the light source module 100 is first reflected by the polarizing beam splitter (PBS) towards the half-wave plate (HWP) and the spatial light modulator (SLM) as linearly polarized light. Then, the reflected linearly polarized light is rotated by π / 8 phase by the half-wave plate (HWP) and then enters the spatial light modulator (SLM). Multiple pixels are distributed on the spatial light modulator (SLM), and each pixel can be switched between ON and OFF states as needed. In this way, through pre-designed intention, pixels in different states on the spatial light modulator (SLM) can rotate the incident light left-hand or right-hand by π / 4 and reflect it. The reflected light passes through the half-wave plate (HWP) again, rotating its phase accordingly, and finally exits through the polarizing beam splitter (PBS). Thus, the light exiting from the polarizing beam splitter (PBS) is modulated to have a π-phase difference between each other due to the presence of pixels in different ON or OFF states of the SLM. That is, the diffraction pattern displayed on the SLM can be treated as a phase grating, and different diffraction patterns can be generated by designing algorithms (e.g., controlling the ON or OFF state of the pixels), thereby achieving cosine fringe light output. The multi-order positive and negative light components generated by the phase grating are passed through a mask, so that only the ±1st and 0th order light components are retained while other order light components are filtered out, thereby generating two light filters. These two light filters can be spaced apart from each other relative to the optical axis. The fluorescence detection module 500 includes a camera, such as a CCD camera or a CMOS camera, to capture fluorescence. The fluorescence generated by the irradiated biological sample is reflected by the spectroscope DM toward the fluorescence detection module 500 and received, and the data is stored for post-processing to obtain super-resolution two-dimensional (2D) or three-dimensional (3D) images.

[0043] Figure 2 The diagram schematically illustrates the optical path of a structured light super-resolution illumination microscopic imaging optical system according to an embodiment of this application. The optical system generally includes a light source module 100, an objective lens 400, and a fluorescence detection module 500 as configured above. For example, the optical system may be a dual-objective optical system, wherein objective lens 400 is used for laser beam input, and the other objective lens (… Figure 1 and 2(Not shown in the image) is used as part of the fluorescence detection module 500 to receive fluorescence generated by the biological sample upon excitation. Furthermore, the structured light super-resolution illumination microscopic imaging optical system according to an embodiment of this application also includes a light sheet generation and phase adjustment module 200' composed of a Wollaston prism 210 disposed between the objective lens 400 and the light source module 100. For example, in... Figure 2 In the illustrated embodiment, the light source module 100 may include a laser 110, downstream of which a collimating lens 120, a half-wave plate 130 (or first half-wave plate), and a beam expander lens group consisting of lenses 140 and 150 are arranged. Lenses 140 and 150 are arranged between the collimating lens 120 and the half-wave plate 130 in a 4F system. Those skilled in the art who encounter any related optical terms such as "galvanometer (or laser galvanometer)," "conjugate," "4F," etc., or their working principles in this specification may refer to any technical resources known in the art, including technical dictionaries, manuals, and textbooks.

[0044] Collimating lens 120 is used to collimate and adjust the laser beam emitted by laser 110 into parallel light, eliminating divergence. Half-wave plate 130 is used to change the polarization direction of the beam passing through it. According to embodiments of this application, half-wave plate 130 can rotate about its central axis (parallel to or coincident with the optical axis of the optical system), for example, half-wave plate 130 is configured with a drive motor designed and manufactured using MEMS technology. Figure 1 and 2 (Not shown in the diagram) to drive its rotation as needed. The beam is expanded by a beam-expanding lens group consisting of lenses 140 and 150 to change the beam diameter (height). For example, the half-wave plate 130 can be supported by a precision rotating frame driven by a motor to rotate the initial polarization direction of the laser beam emitted by the laser 110 of the light source module 100 to a predetermined angle with the optical axis of the Wollaston prism (described below).

[0045] According to an embodiment of this application, the light-generating and phase-adjusting module 200' includes a Wollaston prism 210, which is arranged downstream of the beam-expanding lens group or the light source module 100 in the optical path. The half-wave plate 130 can be selectively rotated to adjust the polarization state of the incident beam passing through the half-wave plate 130 and incident on the Wollaston prism 210 to linearly polarized light at 45° to the optical axis of the Wollaston prism 210, so that two beams of light with equal intensity (ordinary light, o-ray and anomalous light, e-ray) emerge from the Wollaston prism 210. Depending on the manufacturing parameters of the Wollaston prism 210, the two emitted beams can be separated or converged. In an embodiment of this application, the two beams of light emitted from the Wollaston prism 210 are separated from each other. Therefore, according to an embodiment of this application, a beam-contracting lens group consisting of lenses 220 and 230 is arranged downstream of the Wollaston prism 210 to adjust the angle between the two beams. For example, the angles of the two beams passing through the beam-constricting lens group will vary depending on the specifications (e.g., focal length) ratio of lenses 220 and 230. In the illustrated embodiment, a mirror 240 is arranged downstream of the beam-constricting lens group to reduce the space occupied by the optical system. Of course, those skilled in the art will understand that the mirror 240 can be omitted if the space limitations of the optical system are not considered. In addition, a cylindrical lens 250 is arranged downstream of the beam-constricting lens group (downstream of mirror 240 in the illustrated embodiment) to shape the two beams to form one-dimensional focusing plates (or one-dimensional focal line beams) that are focused and compressed along the x-direction and remain parallel along the z-direction. Because the polarization directions of the two beams exiting from the Wollaston prism 210 are perpendicular to each other, it is necessary to ensure that the polarization directions of the two beams are consistent in order to ensure that interference fringes are generated on the rear pupil plane of the objective lens 400 after the two beams subsequently enter the objective lens 400. Therefore, in the optical path of one of the two beams (e.g. Figure 2 A half-wave plate (or second half-wave plate) 260 is arranged in the lower optical path, while in the optical path of the other beam (e.g.) Figure 2 A glass plate 270 is arranged in the upper optical path (center). Preferably, the glass plate 270 is a temperature-controlled glass plate equipped with an electric heating wire, and the temperature of the glass plate can be adjusted accordingly by adjusting the heating power of the electric heating wire. The function of the glass plate 270 is to ensure that the optical path difference between the two beams is consistent. The half-wave plate 260 and the glass plate 270 are arranged in the optical paths of the two beams so that they do not affect the optical path of the other beam.

[0046] To ensure the interference fringes have the desired phase (to meet the requirements of subsequent super-resolution image processing) and to enable dynamic axial scanning of the biological sample 19 as needed, a dual-galvanometer synchronous scanning system can be arranged downstream of the second half-wave plate 260 and the glass plate 270 and between the objective lens 400. This allows the light plates formed after the two beams pass through the objective lens 400 to be scanned along the x and z directions, respectively. It should be clear that in... Figure 2 The diagram illustrates a three-dimensional rectangular coordinate system xyz, where the z-direction is perpendicular to the x-axis. Figure 2 The orientation of the plane in which it is located. It should be clear that the representation of the x-direction and z-direction in the context of the specification is for illustrative purposes only. Those skilled in the art, after understanding the core idea of ​​the technical solution of this application, can also conceive of using other coordinate systems to describe the content of the technical solution of this application.

[0047] like Figure 2 As shown, the dual-galvanometer synchronous scanning system includes a first galvanometer 281 and a second galvanometer 282. Optionally, the dual-galvanometer synchronous scanning system also includes lenses 283 and 284, which are arranged between the first galvanometer 281 and the second galvanometer 282 in a 4F system configuration. The dual-galvanometer synchronous scanning system also includes a scanning lens 285 and a tube lens 286, which are arranged between the second galvanometer 282 and the objective lens 400 in a 4F system configuration. The first galvanometer 281 is configured to scan two one-dimensional focal lines passing through the half-wave plate 260 and the glass plate 270 along the x-direction at, for example, the rear pupil plane of the objective lens by rapidly oscillating (in a manner well-known in the art) to unfold and form two uniform thin light sheets that are superimposed on each other to form a lattice fringe structured light. This dynamic scanning method (using the first galvanometer) can generate an illumination plane that is more uniform and has a controllable thickness than a static light sheet. By selectively rotating the second galvanometer 282 to different positions, the lattice fringe structured light can be scanned along the z-direction, thereby scanning the biological sample 19. In this way, the biological sample 19 is excited to generate a fluorescence signal, which is received by the fluorescence detection module 500.

[0048] In the embodiments described above, the collimating lens 120 and the first half-wave plate 130 can be considered to constitute a polarization state pre-adjustment module, the lens group composed of lenses 140 and 150 and the lens group composed of lenses 220 and 230 constitute a separation angle adjustment module, the cylindrical lens 250 constitutes a one-dimensional shaping module, and the half-wave plate 260 and the glass plate 270 constitute a polarization adjustment and optical path compensation module (to adjust the polarization direction and compensate the optical path of the two one-dimensional focal line beams respectively).

[0049] Therefore, according to one embodiment of this application, an ultrathin light sheet generation device based on Wollaston prism beam splitting interference can be considered to sequentially include a light source module 100, a polarization state pre-adjustment module, a Wollaston prism 210, a one-dimensional shaping module, a polarization adjustment and optical path compensation module, a dual-mirror synchronous scanning module, and an objective lens 400 along the light propagation direction. Optionally, the light sheet generation device may further include a separation angle control module, in which the Wollaston prism 210 is arranged.

[0050] According to one embodiment of this application, the laser of the light source module 100 can be a single-mode diode-pumped solid-state laser (DPSS) or a narrow-linewidth semiconductor laser. Its laser output is the fundamental transverse mode (TEM00), and the coherence length must be greater than the maximum optical path difference (>10m) that may occur between the two beam-splitting optical paths of the system to ensure high-contrast interference fringes. The polarization state pre-tuning module is located at the laser exit. The core element of the polarization state pre-tuning module is the first half-wave plate 130, which can be driven to rotate to rotate the polarization direction of the initial laser beam of the laser to an angle of 45° with the optical axis of the Wollaston prism 210. In this state, the projection intensity of the incident photoelectric vector on the ordinary axis (o-axis) and abnormal axis (e-axis) of the Wollaston prism 210 is equal, to ensure that the two coherent beams after being split by the Wollaston prism 210 have completely consistent amplitudes.

[0051] According to one embodiment of this application, the Wollaston prism 210 is a Wollaston prism made of birefringent crystal. For example, the Wollaston prism 210 is formed by cementing two right-angle prisms with mutually perpendicular optical axes along an inclined plane. Unlike conventional large-angle beam splitters, a small beam-splitting angle design is used. The apex angle of the Wollaston prism 210 is designed as follows: At this angle, for a wavelength of 633nm, its beam splitting angle is approximately... When linearly polarized light is incident, the Wollaston prism 210 can decompose it into ordinary light (o-ray) and anomalous light (e-ray) with mutually perpendicular vibration directions. The two beams are separated at a specific small angle on the exit surface of the prism, while maintaining perfect wavefront continuity.

[0052] The lens groups consisting of lenses 140 and 150 and lenses 220 and 230 constitute two 4F lens systems connected in series with the Wollaston prism 210. The lens group consisting of lenses 140 and 150 is the first-stage 4F system, and the lens group consisting of lenses 220 and 230 is the second-stage 4F system. The main function of the first-stage 4F system is to enlarge the beam aperture while proportionally reducing the separation angle between the two beams, thereby resulting in a wider beam with better spatial coherence. The main function of the second-stage 4F system is to reduce the beam aperture to fit the size of the first and second galvanometers while inversely increasing the separation angle between the two beams. In the illustrated embodiment, lens 220 has a longer focal length, while lens 230 has a shorter focal length.

[0053] According to one embodiment of this application, the cylindrical lens 250 is configured to have optical power in only one direction (e.g., the x-direction in the illustrated embodiment) to compress two circular light spots into two elongated linear beams that propagate parallel in space, forming the basic geometry for the "sheet"-like structure. This linear beam is the aforementioned one-dimensional focal line beam.

[0054] According to one embodiment of this application, the second half-wave plate 260 included in the polarization adjustment and optical path compensation module acts as a polarization rotator, placed in the optical path of one of the two linear beams (e.g., e-beam), rotating its polarization direction by 90 degrees to align it with the polarization direction of the other linear beam (e.g., o-beam). A glass plate 270, acting as an optical path compensator (particularly a temperature-controlled optical path compensator), is placed in the optical path of the other linear beam (e.g., o-beam). According to a preferred embodiment of this application, the glass plate 270 can be a temperature-controlled glass plate 270, serving as a temperature-controlled optical path compensator. For example, the temperature-controlled optical path compensator may include a precision-polished flat glass (generally made of N-BK7 material), mounted in a metal frame with a high-precision temperature sensor (e.g., an NTC thermistor) and a heating element (e.g., a Peltier plate). The optical path of the glass material changes with temperature (thermo-optic coefficient). and coefficient of thermal expansion By finely adjusting the temperature (with an adjustment accuracy of ±0.05℃), the optical path of light passing through the glass can be changed, thereby achieving nanometer-level adjustment of the optical path difference and locking the interference phase.

[0055] According to one embodiment of this application, the first galvanometer 281 of the dual-galvanometer synchronous scanning module is located at the conjugate plane downstream of the cylindrical lens 250, and is used to drive the linear beam to dither at high speed to generate a smooth light sheet and thus form interference fringe light. The second galvanometer 282 is coupled via a lens group composed of lenses 283 and 284 at 4F relay, and can control the movement of the light sheet along the optical axis to achieve slice scanning. According to one embodiment, the generatrix direction of the cylindrical lens 250 is parallel to the rotation axis direction of the first galvanometer 281.

[0056] The following is merely an illustrative and non-limiting description of the working principle of the ultrathin light sheet generation device based on Wollaston prism beam splitting interference according to this application.

[0057] First, the laser beam emitted by the laser in the light source module 100 undergoes beam collimation and energy balance pre-adjustment. In this step (or process), the (typically divergent) laser beam emitted by the laser is transformed into a parallel beam with collimation better than 0.5 mrad by a high numerical aperture collimating lens. Subsequently, the parallel beam passes through the first half-wave plate 130. During the setup and adjustment of the device, the first half-wave plate 130 needs to be precisely rotated while monitoring the power of the two beams subsequently split (via the Wollaston prism 210). When the fast axis of the first half-wave plate 130 forms a specific angle with the laser polarization direction (so that the output polarization is 45° with the optical axis of the Wollaston prism 210), the energies of the o-beam and e-beam split by the Wollaston prism 210 are strictly equal (50:50), which is a prerequisite for ensuring that the interference fringe contrast (at objective lens 400) reaches its maximum value (theoretically 1).

[0058] Then, orthogonal polarization lossless beam splitting is achieved at the Wollaston prism 210. The linearly polarized beam, pre-calibrated and pre-balanced, is incident on the Wollaston prism 210. The beam splits at the crystal interface through birefringence, resulting in two beams. At this point, the two beams have minimal spatial overlap (almost coaxial), but their angles have a slight deviation (approximately 1°).

[0059] A cascaded 4F lens system is used upstream and downstream of the Wollaston prism 210 to achieve beam angle transformation. In the illustrated embodiment, a beam expander consisting of lenses 140 and 150 is used upstream of the Wollaston prism 210, and a beam reducer consisting of lenses 220 and 230 is used downstream of the Wollaston prism 210. The beam first enters the beam expander (upstream of the Wollaston prism 210), assuming the focal length of lens 140 is... The focal length of lens 150 is The beam diameter is then magnified. The separation angle is reduced to times the original value. Subsequently (downstream of Wollaston prism 210), the beam enters the beam-contracting lens group, assuming the focal length of lens 220 is... The focal length of lens 230 is The beam diameter then decreases. The separation angle is magnified by times. Final beam separation angle ,in, The final beam separation angle is the angle between the two beams emitted from the Wollaston prism 210, and it is related to the material properties of the Wollaston prism 210 itself. By selecting a suitable lens combination, the final beam separation angle is adjusted to the range of 3°-5° to match the numerical aperture requirements of the objective lens 400.

[0060] In the apparatus of this application, a cylindrical lens 250 is used to achieve one-dimensional focusing and spatial shaping of the light beam. Two parallel beams of light, after the separation angle adjustment mentioned above, are incident on the cylindrical lens 250. The cylindrical lens 250 is configured to compress and focus a circular light spot in one direction (e.g., the x-direction). At the back focal plane of the cylindrical lens 250, two elongated focal lines are formed. These two focal lines serve as the "seed" light source for subsequently forming the beam profile.

[0061] In the device of this application, the interference conditions are constructed and locked using a polarization adjustment and optical path compensation module. Since the second half-wave plate 260 and the glass plate 270 are located in the optical paths of two slender focal lines respectively, they do not interfere with each other, so the polarization states of the two slender focal lines are parallel. During operation, a pre-programmed PID algorithm is used to control and lock the temperature of the temperature-controlled glass plate 270 at a predetermined value (e.g., 25.00 ℃). If an increase in ambient temperature causes a slight expansion of the mechanical structure, resulting in optical path drift, the system automatically lowers the glass temperature, using a negative optical path change to compensate, ensuring that the phase difference between the two beams reaching the focal plane of the objective lens 400 remains constant.

[0062] In the device of this application, a spatiotemporal composite scanning is achieved using a dual-mirror synchronous scanning module. Two beams of light with parallel polarization states and thin focal lines enter the first mirror 281 of the dual-mirror synchronous scanning module. The first mirror 281 performs a small-amplitude sinusoidal or triangular wave scan at a high frequency (>1kHz) – jittering in the x-direction – causing the interference fringes to move rapidly along the x-direction on the plane of the biological sample 19. Since the exposure time of the camera of the fluorescence detection module 500 (typically >10ms) is much longer than the scanning (jittering) period, the fringe structure is integrated and smoothed, forming a visually uniform light sheet. At the same time, the second mirror 282 can move the light sheet inside the biological sample 19 along the optical axis (e.g., along the z-direction). For example, the second mirror 282 can adopt a stepping mode or a continuous scanning mode, in conjunction with the camera trigger signal of the fluorescence detection module 500, to achieve layer-by-layer slice imaging of the biological sample 19. The specific operation mode of the dual-mirror synchronous scanning module can refer to the known implementation mode of dual-mirror synchronous scanning in existing optical systems.

[0063] In the apparatus of this application, two light plates interfere and fluorescence excitation are achieved at the rear pupil surface of the objective lens 400. Two long, narrow focal beams are imaged onto the rear pupil surface of the objective lens 400 via the tube lens 286. Due to the rapid jitter of the first galvanometer 281, an equivalent "incoherent" ultrathin light plate is formed. The thickness of the light plate depends entirely on the interference aperture angle of the two long, narrow focal beams. Because the apparatus design of this application allows the two long, narrow focal beams to utilize the outermost aperture of the objective lens 400, a minimum light plate thickness (<2µm) close to the diffraction limit can be obtained.

[0064] Furthermore, the Wollaston prism 210 achieves physical beam splitting based on crystal anisotropy, ensuring that the beam wavefront remains spatially continuous without any grating structure (as seen in spatial light modulators (SLMs)). Combined with the smooth scanning of the first galvanometer, this fundamentally eliminates ghosting and fringe artifacts in the optical system.

[0065] Furthermore, according to the device of this application, the lens group design can project two beams of light from slender focal lines onto the outermost edge of the rear focal plane of the objective lens (i.e., at the maximum NA), thereby generating an interference field with a very large numerical aperture. A larger effective NA directly results in a thinner optical sheet and higher axial resolution.

[0066] Furthermore, according to the apparatus of this application, for every 1°C change in the N-BK7 glass used to manufacture the temperature-controlled glass plate 270, the optical path changes by approximately several hundred nanometers. Combined with temperature control accuracy of 0.05°C, optical path fine-tuning at the tens of nanometer level can be achieved, sufficient to resist the normal temperature drift of a laboratory environment, without the need for a complex air-floating vibration isolation table. Preferably, the thickness of the temperature-controlled glass plate 270 is in the range of 5 mm to 15 mm, and its surface is coated with an anti-reflection film for the working wavelength (the wavelength of the laser emitted by the laser).

[0067] In summary, this application overcomes the problem of uneven pixelation in spatial light modulators by employing continuous wavefront beam splitting interference to eliminate the influence of discrete pixels; it overcomes the problem of insufficient axial resolution by combining a small-angle Wollaston prism with a high-NA beam-shrinking lens group to increase the effective numerical aperture; it overcomes the problem of thickness variation with depth by using dual-mirror scanning synchronous control to adjust the position of the optical sheet in real time and maintain constant thickness; it overcomes the problem of environmental drift by using plate glass temperature control and polarization compensation to correct optical path difference and polarization mismatch in real time; and it overcomes the problem of system complexity by reducing active modulation devices and using fully passive optical elements to achieve high-performance optical sheet generation. The optical sheet generation method and device based on Wollaston prism beam splitting interference proposed in this application have many significant advantages and positive effects, the specific beneficial effects of which are as follows: 1. The light sheet exhibits extremely high quality and highly uniform illumination. By abandoning the spatial light modulator (SLM) with its discrete pixel structure and instead using a Wollaston prism with a continuous wavefront for physical birefringence and beam splitting, the periodic noise and ghosting order caused by pixelated diffraction are completely eliminated. Experimental data show that the light sheet generated in this application has a root mean square (RMS) intensity uniformity of ≤3% in the transverse (X-axis) direction, significantly better than the 8%-12% of optical systems using SLMs, providing more reliable raw data for quantitative fluorescence analysis.

[0068] 2. Axial resolution surpasses the diffraction limit, with extremely thin optical sheets. This application, through a cascaded 4F zoom lens system, can precisely control the spacing between the two coherent beams entering the back focal plane of the objective, ensuring they are positioned precisely at the edge of the objective's effective numerical aperture. Using a 1.1 NA water immersion objective, an ultra-thin optical sheet with a full width at half maximum (FWHM, center thickness) ≤ 2.0 µm and an effective interference length ≥ 20 µm can be generated. This is more than 50% thinner than a conventional Gaussian optical sheet, significantly enhancing the optical slicing capability of the optical system.

[0069] 3. Excellent phase stability and resistance to environmental interference. This application innovatively introduces an active temperature-controlled flat glass compensation mechanism. Utilizing the extremely low but controllable thermo-optic coefficient of optical glass such as BK7, it is possible to compensate for optical path difference changes caused by mechanical drift with nanometer-level precision. Experiments have shown that after activating the temperature-controlled PID control loop, the spatial phase drift of the interference fringes is less than 5 nm within 12 hours, fully meeting the requirements for long-term (several days) live embryo development observation.

[0070] 4. Low cost and simple assembly and maintenance. This device mainly consists of standard lenses, prisms, and mechanical parts. The core component, the Wollaston prism, costs only one-fifth to one-tenth of that of a high-resolution SLM. Furthermore, since it does not involve complex algorithmic compensation or numerous pupil plane relay alignments, ordinary optical engineers can quickly complete the assembly and adjustment, greatly reducing the maintenance threshold of high-end microscopy systems.

[0071] 5. Excellent dispersion control. By using a Wollaston prism made of quartz material with a small apex angle (45°), the difference in dispersion angle between different wavelengths is minimized. In multicolor co-imaging at 488nm, 561nm, and 640nm, perfect spatial overlap of the multicolor light sheets can be achieved by finely adjusting the lens position, without sacrificing time resolution for time-division switching as required by spatial light modulators (SLMs).

[0072] The following are brief examples of implementation methods of the apparatus and method of this application. Those skilled in the art should understand that these examples are merely illustrative and not restrictive, and should not be construed as imposing any constraint on the scope of protection claimed in this application.

[0073] Example 1 To realize the optical sheet generation method and corresponding apparatus based on Wollaston prism beam splitting interference proposed in this application, taking a monochromatic 561 nm ultrathin optical sheet as an example, the specific implementation method is as follows: 1. Hardware selection and parameter settings: Light source module 100: adopts a 561nm single longitudinal mode DPSS laser with an output power of 100mW and a coherence length of 30m.

[0074] Polarization state pre-adjustment module: Employs an achromatic lens with a focal length of f=8.0mm and a numerical aperture of 0.1125. After collimation, the laser forms a parallel circular spot with a diameter of 1.8mm; a zero-order quartz half-wave plate 130 is used, for example, mounted on an electrically controlled rotating frame, initially rotated to an angle of 22.5° with the horizontal direction (making the outgoing polarization 45°).

[0075] Wollaston prism 210: Its parameters include a synthetic quartz material and a apex angle of 45°±30''. For a 561nm laser, its actual beam splitting angle was measured (…). The value is 1.045°.

[0076] Separation angle adjustment module: beam expander lens group (focal length of lens 140 = 50mm, focal length of lens 150 = 150mm, magnification 3x); beam reducer lens group (focal length of lens 220 = 100mm, focal length of lens 230 = 50mm, magnification 0.5x).

[0077] One-dimensional shaping module: uses a cylindrical lens 250 with a focal length of f=100mm.

[0078] Polarization adjustment and optical path compensation module: 10mm thick N-BK7 flat glass is used, along with a temperature control plate with an accuracy of ±0.01℃ as the temperature control glass plate 270.

[0079] 2. Detailed implementation steps: S1. Optical axis alignment: Fix the laser of the light source module 100 on the optical platform, adjust the collimating lens 120, and use a shearing interferometer to ensure the collimation of the laser output beam.

[0080] S2, Energy Equalization Adjustment: Place the Wollaston prism 210 into the optical path. Place a power meter behind the prism 210, alternately block the two outgoing beams, and finely adjust the rotation angle of the first half-wave plate 130 until the power of both beams is 48mW (considering approximately 4% surface reflection loss). At this point, the power fluctuation is ≤0.5%.

[0081] S3. Angle Compression and Magnification: After passing through lenses 140 and 150, the beam diameter becomes 5.4 mm, and the separation angle is reduced to approximately 0.35°. Subsequently, after passing through lenses 220 and 230, the beam diameter is restored to approximately 2.7 mm (to match the galvanometer size), and the separation angle is magnified to approximately 0.7°.

[0082] S4. Linear Beam Shaping: The beam passes through a cylindrical lens 250, maintaining a diameter of 2.7mm in the vertical direction, and is focused into two focal lines in the horizontal direction (x direction).

[0083] S5. Phase Locking: Insert a second half-wave plate 260 into one optical path and rotate it 45° to make its polarization state consistent with that of the other optical path (where the temperature-controlled glass plate 270 is inserted). Turn on the temperature control system to preheat and lock the temperature of the temperature-controlled glass plate 270 at 25.00℃.

[0084] S6. Galvanometer Synchronization Adjustment: The first galvanometer 281 scans at a frequency of 2000Hz with an amplitude set to ±1.5° to ensure uniform illumination within the microscope's field of view (approximately 200µm). The second galvanometer 282 moves the slice according to the step signal (500nm per layer).

[0085] S7. Optical sheet synthesis: Two beams of light were focused and interfered through a 1.1 NA water immersion objective lens at 400°. At point 19 of the biological sample, the measured center thickness (FWHM) of the optical sheet was 1.85µm using a fluorescent dye thin film.

[0086] Example 2 For multicolor (488nm / 561nm / 640nm) imaging, multi-wavelength laser beams can be input at the light source module 100 via a beam combiner. Since the Wollaston prism 210 has low dispersion, only at least one of lenses 140, 150, 220, or 230 needs to be fitted with a one-dimensional micro-displacement stage. Thus, when switching wavelengths, the displacement stage can be finely adjusted by approximately ±100µm according to the dispersion deviation of different wavelengths, achieving a high degree of overlap of interference fringes of different colors in z-space.

[0087] Although specific embodiments of this application are described in detail herein, they are provided for illustrative purposes only and should not be construed as limiting the scope of this application. Furthermore, those skilled in the art will understand that the various embodiments described herein can be used in combination with each other. Various substitutions, modifications, and alterations can be conceived without departing from the spirit and scope of this application.

Claims

1. A light sheet generating apparatus, characterized in that, The light sheet generating apparatus comprises, in sequence along the direction of light propagation: A light source module (100) having a laser that generates a laser beam; A polarization state pre-adjustment module is configured to collimate and rotate the polarization direction of the laser beam; A Wollaston prism (210) wherein a laser beam whose polarization direction is rotated by the polarization state pre-tuning module to form a 45° angle with the optical axis of the Wollaston prism (210) is incident on the Wollaston prism (210) to emit two beams of light from the Wollaston prism (210); A one-dimensional shaping module is configured such that the two beams of light are shaped into two linear beams after passing through the one-dimensional shaping module; The polarization adjustment and optical path compensation module has a half-wave plate arranged in the optical path of one of the two linear beams, so that the polarization direction of the linear beam in the optical path is rotated to be consistent with the polarization direction of the other linear beam. The polarization adjustment and optical path compensation module also has a glass plate (270) arranged in the optical path of the other linear beam to ensure that the optical paths of the two optical paths are consistent. A dual-mirror synchronous scanning module includes a first mirror (281) and a second mirror (282). The first mirror (281) is configured to selectively scan the two linear beams in a first direction, and the second mirror (282) is configured to selectively scan the two linear beams in a second direction perpendicular to the first direction. Objective lens (400).

2. The optical sheet generating apparatus according to claim 1, characterized in that, The polarization state pre-adjustment module includes a collimating lens (120) and a first half-wave plate (130) in sequence along the direction of light propagation. The collimating lens (120) collimates the laser beam, and the first half-wave plate (130) rotates the polarization direction of the laser beam to 45° with the optical axis of the Wollaston prism (210).

3. The light sheet generating apparatus according to claim 2 further includes a separation angle control module, the separation angle control module including a beam expanding lens group consisting of a first lens (140) and a second lens (150) located upstream of the Wollaston prism (210); and a beam shrinking lens group consisting of a third lens (220) and a fourth lens (230) located downstream of the Wollaston prism (210).

4. The optical sheet generating apparatus according to claim 3, characterized in that, The first lens (140) and the second lens (150) are arranged in a 4F system between the collimating lens (120) and the first half-wave plate (130); and the third lens (220) and the fourth lens (230) are arranged in a 4F system between the Wollaston prism (210) and the one-dimensional shaping module.

5. The optical sheet generating apparatus according to claim 4, characterized in that, The one-dimensional shaping module includes a cylindrical lens (250), a first galvanometer (281) located at the conjugate plane downstream of the cylindrical lens (250), and the generatrix direction of the cylindrical lens (250) is parallel to the rotation axis direction of the first galvanometer (281).

6. The optical sheet generating apparatus according to claim 5, characterized in that, The dual-galvanometer synchronous scanning system also includes a scanning lens (285) and a tube lens (286), which are arranged between the second galvanometer (282) and the objective lens (400) in a manner that forms a 4F system.

7. The optical sheet generating apparatus according to claim 6, characterized in that, The dual-mirror synchronous scanning system also includes a fifth lens (283) and a sixth lens (284), which are arranged between the first mirror (281) and the second mirror (282) in a manner that forms a 4F system.

8. The optical sheet generating apparatus according to claim 7, characterized in that, The Wollaston prism (210) is made of synthetic quartz and its apex angle is [missing information]. The initial beam splitting angle for a wavelength of 633nm is .

9. The optical sheet generating apparatus according to any one of claims 3 to 8, characterized in that, The glass plate (270) is a temperature-controlled glass plate, so that the temperature is maintained at a predetermined value during the operation of the light sheet generating device.

10. The optical sheet generating apparatus according to claim 9, characterized in that, At least one of the first lens (140), the second lens (150), the third lens (220), and the fourth lens (230) is capable of one-dimensional micro-displacement within a range of ±100µm.

11. A method for producing a light sheet, characterized in that, include: The laser beam is collimated and its polarization direction is rotated so that the polarization direction of the laser beam is at 45° to the optical axis of the Wollaston prism (210) and is incident on the Wollaston prism (210). The two beams of light emitted from the Wollaston prism (210) are shaped into two linear beams; A half-wave plate is arranged in the optical path of one of the two linear beams so that the polarization direction of the linear beam in that optical path is rotated to be consistent with the polarization direction of the other linear beam in the two linear beams, and a glass plate (270) is arranged in the optical path of the other linear beam to ensure that the optical path lengths of the two optical paths are consistent. Two linear beams are passed through a first galvanometer (281), a second galvanometer (282), and an objective lens (400). The first galvanometer (281) is configured to selectively scan the two linear beams in a first direction, and the second galvanometer (282) is configured to selectively scan the two linear beams in a second direction perpendicular to the first direction.

12. The method for generating optical sheets according to claim 11, characterized in that, The laser beam is collimated using a collimating lens (120), and the polarization direction of the laser beam is rotated using a first half-wave plate (130).

13. The method for generating an optical sheet according to claim 12, characterized in that, Also includes: A beam-expanding lens group consisting of a first lens (140) and a second lens (150) is arranged upstream of the Wollaston prism (210); as well as Downstream of the Wollaston prism (210), a beam-shrinking lens group consisting of a third lens (220) and a fourth lens (230) is arranged.

14. The method for generating optical sheets according to claim 13, characterized in that, Two beams of light emitted from the Wollaston prism (210) are shaped into two linear beams using a cylindrical lens (250). The first galvanometer (281) is located at the conjugate plane downstream of the cylindrical lens (250), and the generatrix direction of the cylindrical lens (250) is parallel to the rotation axis direction of the first galvanometer (281).

15. The method for generating optical sheets according to claim 14, characterized in that, The first lens (140) and the second lens (150) are arranged in a 4F system between the collimating lens (120) and the first half-wave plate (130); and the third lens (220) and the fourth lens (230) are arranged in a 4F system between the Wollaston prism (210) and the cylindrical lens (250).

16. The method for generating optical sheets according to claim 15, characterized in that, The scanning lens (285) and the tube lens (286) are arranged between the second galvanometer (282) and the objective lens (400) in a manner that forms a 4F system.

17. The method for generating optical sheets according to claim 16, characterized in that, It also includes arranging a fifth lens (283) and a sixth lens (284) in a manner that forms a 4F system between the first galvanometer (281) and the second galvanometer (282).

18. The method for generating optical sheets according to claim 17, characterized in that, The Wollaston prism (210) is made of synthetic quartz and its apex angle is [missing information]. The initial beam splitting angle for a wavelength of 633nm is .

19. The method for generating a light sheet according to any one of claims 13 to 18, characterized in that, The glass plate (270) is a temperature-controlled glass plate to maintain the temperature at a predetermined value during operation.

20. The method for generating optical sheets according to claim 19, characterized in that, At least one of the first lens (140), the second lens (150), the third lens (220), and the fourth lens (230) is capable of one-dimensional micro-displacement within a range of ±100µm.

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