Transverse cutting self-reference digital holographic microscope based on wedge prism

Abstract

The invention discloses a transverse cutting self-reference digital holographic microscope based on a wedge-shaped prism, and belongs to the field of digital holographic microscopes, the transverse cutting self-reference digital holographic microscope comprises a laser, a sample piece, an objective lens, the wedge-shaped prism and a camera, the laser is used for emitting laser, the sample piece is used for placing a sample, and the objective lens comprises a plurality of lenses arranged in sequence; the sample sheet is arranged between the laser and the objective lens, the objective lens is used for amplifying light beams emitted by the sample sheet, the wedge-shaped prism comprises a first surface and a second surface, an included angle is formed between the first surface and the second surface and is an acute angle, and the wedge-shaped prism is arranged on the side, away from the sample sheet, of the objective lens; wherein laser emitted by the laser irradiates the sample piece, is transmitted to the objective lens through the sample piece, is transmitted to the first surface and the second surface of the wedge-shaped prism through the objective lens, is reflected into a first light beam through the first surface and is reflected into a second light beam through the second surface, and the first light beam and the second light beam are both propagated to the camera, so that the imaging quality can be improved.

Description

Technical Field

[0001] The invention belongs to the technical field of digital holographic microscopes, and in particular relates to a cross-section self-reference digital holographic microscope based on a wedge prism. Background Art

[0002] The cross-section self-referenced digital holographic microscope is a microscope that combines digital holography and self-referenced interferometry, and is mainly used for high-resolution three-dimensional imaging. The cross-section self-referenced digital holographic microscope can reconstruct the three-dimensional information of an object by recording the interference pattern of the scattered light and the reference light of the object. It has the advantages of high resolution, non-invasiveness, and real-time imaging, and is widely used in biomedicine, materials science, and industrial testing.

[0003] The traditional cross-section self-referenced digital holographic microscope uses a thin glass sheet as the core element, and uses the front and rear surfaces of the thin glass sheet to reflect the incident light respectively, so as to form two beams of outgoing light from the sample. Both beams of outgoing light propagate to the detection plane of the camera and interfere with each other to form a hologram. However, when the above structure is adopted, since the lateral displacement of the two beams of light after being reflected by the front and rear surfaces of the thin glass sheet is small, when the size of the sample to be photographed is large, the interference effect of the two beams of light is poor, resulting in that only a shearing image can be formed on the camera, and a hologram cannot be formed, or the image quality of the formed hologram is poor, which in turn causes the digital holographic microscope to be unable to digitally reconstruct and restore the three-dimensional morphology of the sample. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a cross-section self-reference digital holographic microscope based on a wedge prism. The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0005] In a first aspect, the present invention provides a cross-section self-referencing digital holographic microscope based on a wedge prism, comprising:

[0006] Laser, for emitting laser light;

[0007] A sample sheet, used for placing samples;

[0008] An objective lens, comprising a plurality of lenses arranged in sequence, wherein the sample sheet is arranged between the laser and the objective lens, and the objective lens is used to amplify the light beam emitted from the sample sheet;

[0009] A wedge-shaped prism comprises a first surface and a second surface, wherein an angle is formed between the first surface and the second surface, and the angle is an acute angle, and the wedge-shaped prism is arranged at a side of the objective lens away from the sample sheet;

[0010] A camera is arranged opposite to the wedge prism;

[0011] The laser light emitted by the laser is irradiated onto the sample sheet, transmitted through the sample sheet to the objective lens, transmitted through the objective lens to the first surface and the second surface of the wedge-shaped prism, and reflected by the first surface as a first light beam, and reflected by the second surface as a second light beam. Both the first light beam and the second light beam are transmitted to the camera, and the first light beam and the second light beam interfere with each other to form a hologram.

[0012] In one embodiment of the present invention, the angle between the first surface and the second surface is 3°.

[0013] In one embodiment of the present invention, a focusing lens is further included. The focusing lens is disposed between the laser and the sample sheet and is used to converge the laser light emitted by the laser.

[0014] In one embodiment of the present invention, a polarizing plate is further included, and the polarizing plate is arranged between the focusing lens and the sample plate.

[0015] In one embodiment of the present invention, the sample piece is arranged at a focal position of a focusing lens.

[0016] In one embodiment of the present invention, an optical fiber is further included, one end of the optical fiber is connected to the laser, and the other end is directed toward the focusing lens. The laser light emitted by the laser is transmitted to the focusing lens through the optical fiber.

[0017] In one embodiment of the present invention, it further comprises a housing, on which a laser slot, an optical fiber slot, a focusing lens slot, a polarizing plate slot, a sample plate slot, an objective lens slot, a wedge prism slot, and a camera slot are provided;

[0018] The laser is installed in the laser slot, the optical fiber is installed in the optical fiber slot, the focusing lens is installed in the focusing lens slot, the polarizer is installed in the polarizer slot, the sample sheet is installed in the sample sheet slot, the objective lens is installed in the objective lens slot, the wedge prism is installed in the wedge prism slot, and the camera is installed in the camera slot.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] In the above scheme of the present application, a cross-cutting self-referenced digital holographic microscope includes a laser, a sample sheet, an objective lens, a wedge prism and a camera, wherein the laser is used to emit laser light, the sample sheet is used to place the sample, the objective lens includes a plurality of lenses arranged in sequence, the sample sheet is arranged between the laser and the objective lens, the objective lens is used to amplify the light beam emitted from the sample sheet, the wedge prism includes a first surface and a second surface, there is an angle between the first surface and the second surface, and the angle is an acute angle, the wedge prism is arranged on a side of the objective lens away from the sample sheet, and the camera and the wedge prism are arranged opposite to each other; wherein the laser light emitted by the laser is irradiated onto the sample sheet, transmitted to the objective lens through the sample sheet, transmitted to the first surface and the second surface of the wedge prism through the objective lens, and reflected as a first light beam through the first surface, and reflected as a second light beam through the second surface, the first light beam and the second light beam are both propagated to the camera, and the first light beam and the second light beam interfere with each other to form a hologram. With this structure, since there is an angle between the first surface and the second surface of the wedge-shaped prism, and the angle is an acute angle, compared with the traditional digital holographic microscope, the lateral displacement between the first light beam and the second light beam formed by reflection from the first surface and the second surface of the wedge-shaped prism in the present application is larger, and the interference effect between the first light beam and the second light beam is better. Therefore, when the size of the photographed sample is large, the first light beam and the second light beam formed by reflection from the first surface and the second surface of the wedge-shaped prism can interfere with each other and form a hologram, thereby ensuring that the digital holographic microscope can digitally reconstruct and restore the three-dimensional morphology of the sample.

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram of a digital holographic microscope in an embodiment of the present invention;

[0023] Figure 2 is a schematic diagram of the optical path of a light beam reflected by a wedge-shaped prism in an embodiment of the present invention;

[0024] Figure 3 is a schematic diagram of a wedge prism in an embodiment of the present invention;

[0025] Figure 4 Schematic diagram of a housing in an embodiment of the present invention.

[0026] Figure numerals: 1-laser, 2-sample plate, 3-objective lens, 4-wedge prism, 41-first surface, 42-second surface, 5-camera, 6-focusing lens, 7-polarizer, 8-optical fiber, 9-laser slot, 10-optical fiber slot, 11-focusing lens slot, 12-polarizer slot, 13-sample plate slot, 14-objective lens slot, 15-wedge prism slot, 16-camera slot, 17-housing. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0028] The cross-section self-referenced digital holographic microscope is a microscope that combines digital holography and self-referenced interferometry, and is mainly used for high-resolution three-dimensional imaging. The cross-section self-referenced digital holographic microscope can reconstruct the three-dimensional information of an object by recording the interference pattern of the scattered light and the reference light of the object. It has the advantages of high resolution, non-invasiveness, and real-time imaging, and is widely used in biomedicine, materials science, and industrial testing.

[0029] The traditional cross-section self-referenced digital holographic microscope uses a thin glass sheet as the core element, and uses the front and rear surfaces of the thin glass sheet to reflect the incident light respectively, so as to form two beams of outgoing light from the sample. Both beams of outgoing light propagate to the detection plane of the camera and interfere with each other to form a hologram. However, when the above structure is adopted, since the lateral displacement of the two beams of light after being reflected by the front and rear surfaces of the thin glass sheet is small, when the size of the sample to be photographed is large, the interference effect of the two beams of light is poor, and overlap will occur on the detection plane of the camera, resulting in only a shearing image being formed on the camera, and no hologram being formed, or the image quality of the formed hologram is poor, which in turn causes the digital holographic microscope to be unable to digitally reconstruct and restore the three-dimensional morphology of the sample.

[0030] In addition, another traditional cross-section self-referenced digital holographic microscope introduces an electrically adjustable function, which replaces the thin glass plate with a combined polarization beam splitter prism and a reflector with an electrically driven displacement function. The structure can solve the problem of the size of the sample being limited due to the small amount of cutting by controlling the electrically driven displacement of the reflector. However, the light source used in this structure needs to be uniform and stable polarized light, and only when polarized light passes through a polarization beam splitter prism can it be stably split. Therefore, this structure has special requirements for the light source, which limits the use of digital holographic microscopes.

[0031] Based on this, see Figure 1 , Figure 2 , Figure 3 and Figure 4The embodiment of the present invention provides a cross-section self-reference digital holographic microscope based on a wedge prism 4, comprising a laser 1, a sample sheet 2, an objective lens 3, a wedge prism 4 and a camera 5, wherein the laser 1 is used to emit laser light, the sample sheet 2 is used to place a sample, the objective lens 3 comprises a plurality of lenses arranged in sequence, the sample sheet 2 is arranged between the laser 1 and the objective lens 3, the objective lens 3 is used to amplify the light beam emitted from the sample sheet 2, the wedge prism 4 comprises a first surface 41 and a second surface 42, there is an angle between the first surface 41 and the second surface 42, and the angle is an acute angle, the wedge prism 4 is arranged on a side of the objective lens 3 away from the sample sheet 2, and the camera 5 and the wedge prism 4 are arranged opposite to each other; wherein the laser light emitted by the laser 1 is irradiated onto the sample sheet 2, transmitted to the objective lens 3 through the sample sheet 2, transmitted to the first surface 41 and the second surface 42 of the wedge prism 4 through the objective lens 3, and reflected as a first light beam through the first surface 41, and reflected as a second light beam through the second surface 42, the first light beam and the second light beam are both propagated to the camera 5, and the first light beam and the second light beam interfere with each other to form a hologram.

[0032] In some embodiments of the present application, a wedge prism is an optical prism whose two faces are not parallel and are wedge-shaped, and is mainly used to change the optical path or the direction of a light beam.

[0033] In some embodiments of the present application, the wedge-shaped prism 4 is a hexahedral structure, wherein the first surface 41 and the second surface 42 are arranged opposite to each other, and the wedge-shaped prism 4 is arranged at an inclination of 45°.

[0034] In some embodiments of the present application, a lateral misalignment may occur between the first light beam and the second light beam generated by reflection from the first surface 41 and the second surface 42 of the wedge-shaped prism 4 , and the misalignment phenomenon is obvious.

[0035] In some embodiments of the present application, the sample sheet 2 is a transparent sheet.

[0036] In some embodiments of the present application, the objective lens 3 includes a lens barrel, a lens group is arranged in the lens barrel, and the lens group includes convex lenses arranged in sequence along the optical axis. In this way, after the laser enters the objective lens 3 through the sample sheet 2, the objective lens 3 can amplify the light beam to improve the quality of imaging.

[0037] In some embodiments of the present application, Figure 3 As shown, the camera 5 can transmit the hologram formed by the interference of the first light beam and the second light beam to the host computer, and the host computer reconstructs the three-dimensional morphology of the photographed sample based on the hologram through existing known digital means such as background subtraction, Fourier domain filtering, digital refocusing, etc.

[0038] In some embodiments of the present application, the above-mentioned cross-cutting self-referencing digital holographic microscope can be used in the fields of biomedicine, micro-nano technology, optical communications, materials science, optical sensing, photon computing and quantum information. In the biomedical field, the cross-cutting self-referencing digital holographic microscope can be used to study micro-nano biological particles such as viruses and cells. The digital holographic microscope has good time stability, so it can realize real-time observation of biological particles, obtain information such as their particle size, concentration, and motion trajectory, and provide important data support for virus research, vaccine development, drug delivery and other fields. In the field of optical communications, in industrial production, the digital holographic microscope can be used to monitor the micro-nano surface structure of products in the production process, help optimize the production process, and improve product quality and output.

[0039] In the above scheme of the present application, the cross-cutting self-reference digital holographic microscope includes a laser 1, a sample sheet 2, an objective lens 3, a wedge prism 4 and a camera 5, wherein the laser 1 is used to emit laser light, the sample sheet 2 is used to place a sample, the objective lens 3 includes a plurality of lenses arranged in sequence, the sample sheet 2 is arranged between the laser 1 and the objective lens 3, the objective lens 3 is used to amplify the light beam emitted from the sample sheet 2, the wedge prism 4 includes a first surface 41 and a second surface 42, there is an angle between the first surface 41 and the second surface 42, and the angle is an acute angle, the wedge prism 4 is arranged on a side of the objective lens 3 away from the sample sheet 2, and the camera 5 and the wedge prism 4 are arranged opposite to each other; wherein the laser light emitted by the laser 1 is irradiated onto the sample sheet 2, transmitted to the objective lens 3 through the sample sheet 2, transmitted to the first surface 41 and the second surface 42 of the wedge prism 4 through the objective lens 3, and reflected as a first light beam through the first surface 41, and reflected as a second light beam through the second surface 42, the first light beam and the second light beam are both propagated to the camera 5, and the first light beam and the second light beam interfere with each other to form a hologram. With this structure, since there is an angle between the first surface 41 and the second surface 42 of the wedge prism 4, and the angle is an acute angle, compared with the traditional digital holographic microscope, the lateral displacement between the first light beam and the second light beam formed by the reflection of the first surface 41 and the second surface 42 of the wedge prism 4 in the present application is larger, and the interference effect between the first light beam and the second light beam is better, so when the size of the sample photographed is large, the first light beam and the second light beam formed by the reflection of the first surface 41 and the second surface 42 of the wedge prism 4 can interfere with each other and form a hologram, thereby ensuring that the digital holographic microscope can digitally reconstruct and restore the three-dimensional morphology of the sample. In addition, when the wedge prism 4 is used, since the wedge prism 4 has a small light intensity loss, it can be ensured that the first light beam and the second light beam that interfere with each other have a small light intensity difference, thereby improving the high contrast of the image. In addition, the digital holographic microscope of the present application is smaller in size, lighter, and easier to carry and operate. At the same time, it has higher imaging contrast, time and space stability, and the ability to shoot large-size samples, so that the digital holographic microscope has higher versatility and continuous shooting capabilities.

[0040] In some embodiments of the present application, Figure 1 and Figure 3 As shown, the angle between the first surface 41 and the second surface 42 is 3°. With this structure, it is possible to ensure that the first light beam and the second light beam have a good interference effect. This design can select wedge mirrors with different angles for imaging according to different test samples or test purposes.

[0041] In some embodiments of the present application, the cross-section self-reference digital holographic microscope further includes a focusing lens 6, which is disposed between the laser 1 and the sample sheet 2, and is used to converge the laser light emitted by the laser 1. With this structure, the laser light beam is converged by the focusing lens 6, and the imaging quality can be further improved.

[0042] In some embodiments of the present application, Figure 1 As shown, the cross-section self-reference digital holographic microscope further includes a polarizer 7, which is disposed between the focusing lens 6 and the sample sheet 2. With this structure, the polarizer 7 can convert the random polarization state of light into uniform linear polarized light. By unifying the polarization state of the light source through the polarizer 7, the image contrast can be enhanced, the imaging quality can be improved, and the selection criteria of the laser 1 can be relaxed.

[0043] In some embodiments of the present application, Figure 1 As shown, the sample sheet 2 is set at the focal position of the focusing lens 6. With this structure, since the spot size at the focal position is the smallest, the light intensity is the largest and the aberration is small, the image brightness and contrast can be improved, the image aberration can be reduced, and the image quality can be further improved.

[0044] In some embodiments of the present application, Figure 1 As shown, the cross-section self-reference digital holographic microscope also includes an optical fiber 8, one end of which is connected to the laser 1, and the other end is directed toward the focusing lens 6. The laser light emitted by the laser 1 is transmitted to the focusing lens 6 through the optical fiber 8. With this structure, the emission direction of the laser light can be changed through the optical fiber 8, thereby ensuring that the laser light can be transmitted to the focusing lens 6 along the optical axis direction of the focusing lens 6. At the same time, the setting direction of the laser 1 is optimized, the lateral size of the cross-section self-reference digital holographic microscope is reduced, and the integration of the cross-section self-reference digital holographic microscope is improved.

[0045] In some embodiments of the present application, the laser 1 is arranged in a vertical direction, and the optical fiber 8 includes a vertical section, an arc-shaped transition section, and a horizontal section connected in sequence, the vertical section is connected to the laser 1, and the horizontal section faces the focusing lens 6.

[0046] In some embodiments of the present application, Figure 1 and Figure 4As shown, the cross-cutting self-reference digital holographic microscope also includes a shell 17, on which are provided a laser slot 9, an optical fiber slot 10, a focusing lens slot 11, a polarizer slot 12, a sample plate slot 13, an objective lens slot 14, a wedge prism slot 15 and a camera slot 16; the laser 1 is installed in the laser slot 9, the optical fiber 8 is installed in the optical fiber slot 10, the focusing lens 6 is installed in the focusing lens slot 11, the polarizer 7 is installed in the polarizer slot 12, the sample plate 2 is installed in the sample plate slot 13, the objective lens 3 is installed in the objective lens slot 14, the wedge prism 4 is installed in the wedge prism slot 15, and the camera 5 is installed in the camera slot 16. By adopting this structure, the laser 1, optical fiber 8, focusing lens 6, polarizer 7, sample film 2, objective lens 3, wedge prism 4 and camera 5 are positioned respectively through the laser groove 9, optical fiber groove 10, focusing lens groove 11, polarizer groove 12, sample film groove 13, objective lens groove 14, wedge prism groove 15 and camera groove 16, which can improve the installation accuracy and stability of each component, thereby improving the overall stability of the cross-cutting self-reference digital holographic microscope.

[0047] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0049] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0050] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A cross-section self-referencing digital holographic microscope based on a wedge prism, characterized in that: include: Laser, for emitting laser light; A sample sheet, used for placing samples; An objective lens, comprising a plurality of lenses arranged in sequence, wherein the sample sheet is arranged between the laser and the objective lens, and the objective lens is used to amplify the light beam emitted from the sample sheet; A wedge-shaped prism, comprising a first surface and a second surface, wherein an angle is formed between the first surface and the second surface, and the angle is an acute angle, and the wedge-shaped prism is arranged on a side of the objective lens away from the sample sheet; A camera, arranged opposite to the wedge-shaped prism; The laser light emitted by the laser irradiates the sample sheet, is transmitted to the objective lens through the sample sheet, is transmitted to the first surface and the second surface of the wedge prism through the objective lens, and is reflected as a first light beam through the first surface and as a second light beam through the second surface. Both the first light beam and the second light beam are transmitted to the camera, and the first light beam and the second light beam interfere with each other to form a hologram.

2. The wedge-prism-based cross-section self-referencing digital holographic microscope according to claim 1, characterized in that: The angle between the first surface and the second surface is 3°.

3. The wedge-prism-based cross-section self-referencing digital holographic microscope according to claim 1, characterized in that: The invention also comprises a focusing lens, which is arranged between the laser and the sample sheet and is used for converging the laser light emitted by the laser.

4. The wedge-prism-based cross-section self-referencing digital holographic microscope according to claim 3, characterized in that: The invention also comprises a polarizing plate, wherein the polarizing plate is arranged between the focusing lens and the sample plate.

5. The wedge-prism-based cross-section self-referencing digital holographic microscope according to claim 4, characterized in that: The sample piece is arranged at the focal position of the focusing lens.

6. The wedge-prism-based cross-section self-referencing digital holographic microscope according to claim 4, characterized in that: It also includes an optical fiber, one end of which is connected to the laser and the other end of which is directed toward the focusing lens. The laser light emitted by the laser is transmitted to the focusing lens through the optical fiber.

7. The wedge-prism-based cross-section self-referencing digital holographic microscope according to claim 6, characterized in that: It also includes a housing, on which a laser slot, an optical fiber slot, a focusing lens slot, a polarizer slot, a sample plate slot, an objective lens slot, a wedge prism slot, and a camera slot are provided; The laser is installed in the laser groove, the optical fiber is installed in the optical fiber groove, the focusing lens is installed in the focusing lens groove, the polarizer is installed in the polarizer groove, the sample plate is installed in the sample plate groove, the objective lens is installed in the objective lens groove, the wedge prism is installed in the wedge prism groove, and the camera is installed in the camera groove.

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