A holographic lens-based metasurface three-dimensional holographic display method

Abstract

A holographic lens-based metasurface three-dimensional holographic display method, on the basis of computer holography, by integrating multiple layers of holographic lenses with different focal lengths, the holographic lens is combined with different depth images of the three-dimensional scene, the calculation time is shortened, the image quality is improved, and three-dimensional display is realized, characterized in that, step 1, a three-dimensional object is cut into N depth layer plane images from the first longitudinal depth to the Nth longitudinal depth, N is a positive integer, one depth layer plane image is superimposed with one holographic lens, and the greater the depth of the depth layer plane image, the greater the focal length of the corresponding holographic lens; step 2, the phase information of the N depth layer plane images and the N holographic lenses after being superimposed one by one is phase-encoded using a metasurface unit structure, and the hologram phase information is encoded onto the metasurface structure on the metasurface substrate; step 3, a three-dimensional metasurface holographic reconstruction system is used to realize three-dimensional holographic display of the three-dimensional object.

Description

Technical Field

[0001] The present invention relates to the field of holographic display technology, and in particular to a metasurface three-dimensional holographic display method based on a holographic lens. Background Art

[0002] Humans perceive the world through five sensory modalities: sight, hearing, touch, taste, and smell. Numerous studies have shown that vision is the primary means of human perception, accounting for 80% of external content. This demonstrates the crucial importance of vision in information acquisition. As a tool for conveying visual information, display technology has undergone a long and continuous development, driven by people's pursuit of visual information and their need to explore visual systems.

[0003] The development of display technology has undergone a series of advancements, from static to dynamic, from black and white to color, and from standard definition to blue light. However, these advances have been largely confined to the field of two-dimensional displays. With the continuous evolution of technology and the rise of human needs, people naturally desire more realistic three-dimensional displays. Therefore, it is foreseeable that future display technology will focus primarily on the three-dimensional field. Among current three-dimensional display technologies, holographic three-dimensional display technology is widely recognized as a superior 3D display technology with broad application prospects and development potential due to its ability to completely record and reconstruct the wavefront of an object and provide all the depth information required by the human visual system. Furthermore, it has become a focus of global research. Metasurfaces, due to their exceptional light field manipulation capabilities, have been widely used in 3D holographic displays.

[0004] With the development of computer technology, computational holography has become widely used in metasurface 3D holographic displays. However, 3D computational holography suffers from the problem of large amounts of computational data, which constantly requires a trade-off between computational time and image quality, severely restricting its display applications. Although holographic lenses have been applied in metasurface holographic displays, traditional methods are limited in focal length and difficult to achieve with complex phase encoding. This means that the target object can only be integrated with a single holographic lens, resulting in only 2D holographic displays, not 3D effects. Summary of the Invention

[0005] In response to the problems of long calculation time, large data volume and poor image quality in the existing supersurface three-dimensional computer holography, the present invention proposes a supersurface three-dimensional holographic display method based on holographic lenses. On the basis of computer holography, by integrating multiple layers of holographic lenses with different focal lengths into it, the holographic lenses are combined with images of different depths of the three-dimensional scene, which shortens the calculation time, improves the image quality and realizes three-dimensional display.

[0006] The technical solutions of the present invention are as follows:

[0007] A 3D holographic display method of a metasurface based on a holographic lens, characterized by comprising the following steps:

[0008] Step 1: Cut the three-dimensional object into N depth-layer plane images from the first longitudinal depth to the Nth longitudinal depth, where N is a positive integer. One depth-layer plane image is superimposed with one holographic lens. The greater the depth of the depth-layer plane image, the greater the focal length of the corresponding holographic lens.

[0009] Step 2: Phase-encode the phase information of the N depth layer plane images and the N holographic lenses after interleaving and superimposing them one by one using the metasurface unit structure, and encode the hologram phase information into the metasurface structure on the metasurface substrate;

[0010] Step 3: Use a three-dimensional metasurface holographic reconstruction system to realize three-dimensional holographic display of the three-dimensional object.

[0011] Step 2 includes generating a phase map using a superposition calculation method. The phase map contains a total of 1960*1200 phase points, each of which has a phase value from 0 to 255. The multi-layer depth phase is encoded according to the superposition of the holographic lens.

[0012] The metasurface in the metasurface structure in step 2 is a geometric phase metasurface, a resonant phase metasurface, or a propagation phase metasurface.

[0013] In step 2, the material used for the metasurface unit structure is silicon, amorphous silicon, gold or aluminum, and the material used for the metasurface substrate is silicon or silicon dioxide.

[0014] Step 2 includes controlling the aspect ratio, height and / or rotation angle of the metasurface unit structure to produce different phases, and matching the phase map generated by the superposition calculation method for encoding.

[0015] The three-dimensional metasurface holographic reconstruction system in step 3 includes a laser, a first linear polarizer, a first quarter-wave plate, a metasurface, a microscope objective, a second quarter-wave plate, a second linear polarizer and a camera connected in sequence. The output light of the laser is converted into circularly polarized light after passing through the first linear polarizer and the first quarter-wave plate, exciting the metasurface of the encoded hologram, and the image is amplified by the microscope objective. The second quarter-wave plate and the second linear polarizer filter zero-order noise, and the camera receives the holographic image.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The present invention proposes to use holographic lenses with different focal lengths to integrate images with different depths of field to achieve three-dimensional holographic display, which overcomes the problem that traditional holographic lens metasurface holographic display can only display two dimensions due to focal length limitations. It is a brand-new method.

[0018] (2) The method provided in this application reduces the amount of data required for three-dimensional holography calculations and increases the speed of calculation.

[0019] (3) The method provided in this application reduces the inter-layer crosstalk of the three-dimensional holographic display and improves the image quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the process of implementing a metasurface three-dimensional holographic display method based on a holographic lens of the present invention. Figure 1 The method includes cutting the annular knot into four plane images according to depth, superimposing a holographic lens on one plane image, and the greater the depth of the plane image, the larger the focal length of the corresponding holographic lens. After the plane image and the holographic lens are superimposed layer by layer, the phase information of the hologram is encoded into the metasurface structure on the metasurface substrate through phase encoding. Figure 1 1- A three-dimensional object (specifically a ring knot) cut into four layers according to depth, 2- Four holographic lenses with different focal lengths, 3- A metasurface unit structure (rectangular columns with different orientations) obtained by phase encoding by stacking the three-dimensional object and holographic lenses with different focal lengths layer by layer, 4- Metasurface substrate.

[0021] Figure 2 It is a structural schematic diagram of a three-dimensional metasurface holographic reconstruction system involved in implementing a metasurface three-dimensional holographic display method based on a holographic lens of the present invention. Figure 2 The method includes a laser, a first linear polarizer, a first quarter-wave plate, a metasurface, a microscope objective, a second quarter-wave plate, a first linear polarizer, and a camera, which are connected in sequence. Figure 2 21 - laser, 22 - first linear polarizer, 23 - first quarter-wave plate, 24 - metasurface, 25 - microscope objective, 26 - second quarter-wave plate, 27 - first linear polarizer, 28 - camera.

[0022] Figure 3 Schematic diagram of three holographic lenses with different focal lengths. Figure 3 From left to right in the middle are 31-holographic lens with a focal length of 400um, 32-holographic lens with a focal length of 700um, and 33-holographic lens with a focal length of 1000um.

[0023] Figure 4 It is an image of a ring segment of a three-dimensional target display object. Figure 4 The annular segment image in the image has xy plane information and z direction depth information, and can be cut in layers according to depth.

[0024] Figure 5 It is a three-dimensional holographic phase image of a metasurface based on a holographic lens involving three layers of depth of field.

[0025] Figure 6is a holographic lens-based metasurface three-dimensional holographic reconstruction image involving three layers of depth of field. Figure 6 In the figure, from left to right, 61 is a holographic reconstruction image with a focal length of 400 um, 62 is a holographic reconstruction image with a focal length of 700 um, and 63 is a holographic reconstruction image with a focal length of 1000 um.

[0026] Figure 7 is a holographic lens-based metasurface three-dimensional holographic phase image involving seven layers of depth of field.

[0027] Figure 8 is a holographic lens-based metasurface three-dimensional holographic reconstruction image involving seven layers of depth of field. Figure 8 In the figure, from left to right, 81 is a holographic reconstruction image with a focal length of 400 um, 82 is a holographic reconstruction image with a focal length of 500 um, 83 is a holographic reconstruction image with a focal length of 600 um, 84 is a holographic reconstruction image with a focal length of 700 um, 85 is a holographic reconstruction image with a focal length of 800 um, 86 is a holographic reconstruction image with a focal length of 900 um, and 87 is a holographic reconstruction image with a focal length of 1000 um. DETAILED DESCRIPTION

[0028] The present application will be described below in conjunction with the accompanying drawings Figures 1-8 and examples.

[0029] Figure 1 is a process diagram for implementing a holographic lens-based metasurface three-dimensional holographic display method according to the present application. Figure 2 is a structure diagram of a three-dimensional metasurface holographic reconstruction system involved in a holographic lens-based metasurface three-dimensional holographic display method according to the present application. Figure 3 is a schematic diagram of three holographic lenses with different focal lengths. Figure 4 is an image of a ring-shaped section of a three-dimensional target display object. Figure 5 is a holographic lens-based metasurface three-dimensional holographic phase image involving three layers of depth of field. Figure 6 is a holographic lens-based metasurface three-dimensional holographic reconstruction image involving three layers of depth of field. Figure 7 is a holographic lens-based metasurface three-dimensional holographic phase image involving seven layers of depth of field. Figure 8 is a holographic lens-based metasurface three-dimensional holographic reconstruction image involving seven layers of depth of field. Reference Figures 1 to 8As shown, a metasurface three-dimensional holographic display method based on a holographic lens includes the following steps: Step 1, cutting a three-dimensional object into N depth layer plane images from a first longitudinal depth to an Nth longitudinal depth, where N is a positive integer, and superimposing one depth layer plane image on one holographic lens. The greater the depth of the depth layer plane image, the greater the focal length of the corresponding holographic lens; Step 2, using a metasurface unit structure to phase encode the phase information after the N depth layer plane images and the N holographic lenses are interlaced and superimposed one by one, and encoding the hologram phase information onto the metasurface structure on the metasurface substrate; Step 3, using a three-dimensional metasurface holographic reconstruction system to realize three-dimensional holographic display of the three-dimensional object.

[0030] Step 2 includes generating a phase map using a superposition calculation method, wherein the phase map contains a total of 1960*1200 phase points, each phase point has a phase value from 0 to 255, and the multi-layer depth phase is encoded according to the superposition of the holographic lens. The metasurface in the metasurface structure in step 2 is a geometric phase metasurface, a resonant phase metasurface, or a propagation phase metasurface. The material used for the metasurface unit structure in step 2 is silicon, amorphous silicon, gold, or aluminum, and the material used for the metasurface substrate is silicon or silicon dioxide. Step 2 includes controlling the aspect ratio, height, and / or rotation angle of the metasurface unit structure to produce different phases, and matching and encoding them with the phase map generated using the superposition calculation method.

[0031] The three-dimensional metasurface holographic reconstruction system in step 3 includes a laser 21, a first linear polarizer 22, a first quarter-wave plate 23, a metasurface 24, a microscope objective 25, a second quarter-wave plate 26, a second linear polarizer 27 and a camera 28 connected in sequence. The output light of the laser 21 is converted into circularly polarized light after passing through the first linear polarizer 22 and the first quarter-wave plate 23, and excites the metasurface 24 of the encoded hologram. The image is amplified by the microscope objective 25, the second quarter-wave plate 26 and the second linear polarizer 27 filter the zero-order noise, and the camera 28 receives the holographic image.

[0032] The present invention relates to a holographic lens-based metasurface 3D holographic display method. The method's technical process involves integrating multiple layers of holographic lenses with varying focal lengths into computational holography. These holographic lenses are combined with images of a 3D scene at varying depths, which are then encoded onto a metasurface with ultra-high light field modulation capabilities. A metasurface 3D holographic reconstruction system is then used to achieve 3D holographic display. By utilizing a multi-focal-length holographic lens design and a layer-by-layer stacking method, this method overcomes the limitations of traditional holographic lens metasurface holography, which is limited to two-dimensional display. This method addresses the existing problems of metasurface 3D computational holography, such as long computation time, large data volumes, and poor image quality.

[0033] A metasurface three-dimensional holographic display method based on holographic lenses. The process of this method is as follows: when calculating the hologram, images of different depths of the three-dimensional scene are added to holographic lenses with different focal lengths, and then multi-depth hologram superposition calculations are performed. The obtained hologram phase information is encoded into the metasurface unit structure, and a three-dimensional metasurface holographic reconstruction system is used to realize three-dimensional metasurface holographic display.

[0034] The holographic lens-based metasurface three-dimensional holographic display method comprises the following steps:

[0035] (1) Cut the three-dimensional object into different depth layers according to depth, superimpose the image of each depth layer on a holographic lens, the focal length of the holographic lens corresponds to the depth of the image, and calculate the phase information after superposition;

[0036] (2) Encoding phase information using the unit structure of the metasurface;

[0037] (3) Use the three-dimensional metasurface holographic reconstruction system to realize three-dimensional holographic display.

[0038] The method of computational holography is:

[0039] (1) Cut the three-dimensional scene based on depth to form images of different depths;

[0040] (2) Adding holographic lenses with different focal lengths to holograms at different depths can reduce the amount of algorithm data and inter-layer crosstalk, thereby improving the quality of 3D holographic display.

[0041] (3) Multi-depth hologram superposition calculation to generate phase map.

[0042] The described super surface encoding method is as follows:

[0043] (1) The metasurface can be any one of a geometric phase metasurface, a resonant phase metasurface, and a propagation phase metasurface;

[0044] (2) The unit structure material of the metasurface can be any one of silicon, amorphous silicon, gold, and aluminum, and the substrate of the metasurface can be silicon dioxide or silicon;

[0045] (3) By controlling the aspect ratio, height, and rotation angle of the metasurface unit structure, it produces different phases and matches the calculated phase map for encoding.

[0046] The three-dimensional metasurface holographic reconstruction system is composed of a laser, a linear polarizer, a quarter-wave plate, a microscope objective, a camera and a metasurface, the outgoing light of the laser is converted into circularly polarized light through the linear polarizer and the quarter-wave plate, the metasurface of the coded hologram is excited, the image is magnified through the microscope objective, the zero-order noise is filtered through the quarter-wave plate and the linear polarizer, and the holographic image is received by the camera.

[0047] Reference Figure 1 The three-dimensional object "ring knot" is cut into four planar images according to depth, an image on each depth layer is superimposed on a holographic lens, the focal length of the holographic lens corresponds to the depth of the image, the superimposed phase information is calculated and encoded on the metasurface unit structure, and the number of layers can be set as required. Figure 2 The three-dimensional metasurface holographic reconstruction system is composed of a laser, a linear polarizer, a quarter-wave plate, a microscope objective, a camera and a metasurface, the outgoing light of the laser is converted into circularly polarized light through the linear polarizer and the quarter-wave plate, the metasurface of the coded hologram is excited, the image is magnified through the microscope objective, the zero-order noise is filtered through the quarter-wave plate and the linear polarizer, and the holographic image is received by the camera. Figure 3 The holographic lenses with different focal lengths generated in embodiment 1. Figure 4-Figure 6 The experimental results of the metasurface three-dimensional hologram (three-layer depth of field) based on the holographic lens in embodiment 2. Figure 7-Figure 8 The experimental results of the metasurface three-dimensional hologram (seven-layer depth of field) based on the holographic lens in embodiment 3.

[0048] Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the present disclosure should be understood in their usual meanings by those skilled in the art.

[0049] In order to make the technical objects, technical solutions and beneficial effects of the present application clearer, a holographic lens-based metasurface three-dimensional holographic display method according to an embodiment of the present application is described below with reference to the drawings and specific exemplary embodiments.

[0050] Embodiment 1: holographic lenses with different focal lengths

[0051] The method comprises the following steps:

[0052] (1) As shown in Figure 3 , holographic lenses with focal lengths of 400 um (identifier 31), 700 um (identifier 32) and 1000 um (identifier 33) are designed.

[0053] (2) The smaller the focal length, the larger the central circle, and the fewer the number of rings for the same area; the larger the focal length, the smaller the central circle, and the more the number of rings for the same area.

[0054] Example 2: Metasurface 3D Holography (Three-layer Depth of Field) Based on Holographic Lenses

[0055] The steps include:

[0056] (1) Target object ring segment ( Figure 4 ) is a three-dimensional object. In addition to the xy plane, the image also has depth information along the z direction. It is cut into three layers according to the depth.

[0057] (2) The three layers of images with different depths of field after cutting are superimposed with three holographic lenses with different focal lengths, and the focal lengths of the holographic lenses are 400um, 700um, and 1000um respectively.

[0058] (3) Using the superposition calculation method, a phase diagram is generated, such as Figure 5 As shown, the calculation time is only 0.36 seconds. The phase map contains a total of 1960*1200 phase points, each with a phase value between 0-255. Due to the superposition of holographic lenses, the multi-layer depth phase is effectively encoded, and an obvious phase mutation effect appears in the center of the phase map.

[0059] (4) The unit structure of the metasurface is a nanocolumn structure made of amorphous silicon. The nanocolumns are 200 nm long, 100 nm wide, and 500 nm high. They are rotated at different angles to provide phase shift with the holographic phase. Figure 1 The nanorods were fabricated on a silica substrate with a consistent phase.

[0060] (5) Using the holographic reconstruction system to generate holographic display images, such as Figure 6 As shown, the laser light with a wavelength of 808nm is converted into circularly polarized light after passing through a linear polarizer and a quarter-wave plate, which excites the metasurface of the encoded hologram. The image is amplified by a microscope objective lens, the zero-order noise is filtered using a quarter-wave plate and a linear polarizer, and the holographic image is received by a camera.

[0061] (6) By moving the camera back and forth to receive holographic images at different depths, the image at the first depth of the annular segment is observed at a focal length of 61, the image at the second depth of the annular segment is observed at a focal length of 62, and the image at the third depth of the annular segment is observed at a focal length of 63. The layers are spliced ​​together to present a three-dimensional holographic display effect in the object space. The holographic image of each layer is clear and there is no crosstalk between layers.

[0062] Example 3: Metasurface 3D Holography Based on Holographic Lenses (Seven-Layer Depth of Field)

[0063] The steps include:

[0064] (1) Ring segment the three-dimensional target object ( Figure 4 ) The depth in the z direction is used as a clue to perform layered cutting, and the layer is cut into seven layers.

[0065] (2) The seven layers of images with different depths of field after cutting are superimposed with seven holographic lenses with different focal lengths. The focal lengths of the holographic lenses are 400um, 500um, 600um, 700um, 800um, 900um, and 1000um respectively.

[0066] (3) Using the superposition calculation method, a phase diagram is generated, such as Figure 7 As shown, the calculation time is only 0.81 seconds. The phase map contains a total of 1600*1200 phase points, each with a phase value between 0-255. Due to the superposition of holographic lenses, the multi-layer deep phase is effectively encoded. Due to the large number of layers, the phase mutation area in the center of the phase map becomes larger.

[0067] (4) The unit structure of the metasurface is a nanocylindrical structure made of gold. The nanocylinder is 600nm high and has a diameter of 100nm-300nm. Different diameters are used to provide a phase consistent with the holographic phase image. The metasurface unit structure is processed on a silicon substrate.

[0068] (5) Using the holographic reconstruction system to generate holographic display images, such as Figure 8 As shown, the laser light with a wavelength of 795nm is converted into circularly polarized light after passing through a linear polarizer and a quarter-wave plate, which excites the metasurface of the encoded hologram. The image is amplified by a microscope objective lens, the zero-order noise is filtered using a quarter-wave plate and a linear polarizer, and the holographic image is received by a camera.

[0069] (6) By moving the camera back and forth to receive holographic images at different depths, the image at the first depth of the annular segment is observed at focal length 81, the image at the second depth of the annular segment is observed at focal length 82, the image at the third depth of the annular segment is observed at focal length 83, the image at the fourth depth of the annular segment is observed at focal length 84, the image at the fifth depth of the annular segment is observed at focal length 85, the image at the sixth depth of the annular segment is observed at focal length 86, and the image at the seventh depth of the annular segment is observed at focal length 87. By splicing the layers together, a three-dimensional holographic display effect can be presented in the object space. The holographic image of each layer is clear and there is no crosstalk between layers. As the number of layers increases, the three-dimensional depth information increases, and the holographic display effect is significantly improved.

[0070] The contents not described in detail in the specification of the present invention belong to the prior art known to those skilled in the art.

[0071] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any form. Any person skilled in the art who, without departing from the scope of the technical solution of the present invention, utilizes the technical content disclosed above to make more possible changes and modifications to the technical solution of the present invention, or modifications are all equivalent embodiments of the present invention. Therefore, any equivalent and equivalent changes made in accordance with the ideas of the present invention without departing from the content of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0072] It should be understood that the foregoing describes only some embodiments, and changes, modifications, additions and / or variations may be made without departing from the scope and spirit of the disclosed embodiments, which are illustrative and not restrictive. In addition, the embodiments described relate to what are currently considered to be the most practical and preferred embodiments, and it should be understood that the embodiments should not be limited to the disclosed embodiments, but rather are intended to cover different modifications and equivalent arrangements that are included within the spirit and scope of the embodiments. In addition, the various embodiments described above may be used in conjunction with other embodiments, such as aspects of one embodiment may be combined with aspects of another embodiment to achieve yet another embodiment. In addition, each independent feature or component of any given component may constitute another embodiment.

[0073] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A three-dimensional holographic display method based on a holographic lens, characterized in that: The following steps are involved: Step 1: Cut the three-dimensional object into N depth-layer plane images from the first longitudinal depth to the Nth longitudinal depth, where N is a positive integer. One depth-layer plane image is superimposed with one holographic lens. The greater the depth of the depth-layer plane image, the greater the focal length of the corresponding holographic lens. Step 2: Phase-encode the phase information of the N depth layer plane images and the N holographic lenses after interleaving and superimposing them one by one using the metasurface unit structure, and encode the hologram phase information into the metasurface structure on the metasurface substrate; Step 3: Use a three-dimensional metasurface holographic reconstruction system to realize three-dimensional holographic display of the three-dimensional object.

2. The method for three-dimensional holographic display based on a holographic lens according to claim 1, characterized in that: Step 2 includes generating a phase map using a superposition calculation method. The phase map contains a total of 1960*1200 phase points, each of which has a phase value from 0 to 255. The multi-layer depth phase is encoded according to the superposition of the holographic lens.

3. The method for three-dimensional holographic display based on a holographic lens on a metasurface according to claim 1, wherein: The metasurface in the metasurface structure in step 2 is a geometric phase metasurface, a resonant phase metasurface, or a propagation phase metasurface.

4. The method for three-dimensional holographic display based on a holographic lens metasurface according to claim 1, wherein: In step 2, the material used for the metasurface unit structure is silicon, gold or aluminum, and the material used for the metasurface substrate is silicon or silicon dioxide.

5. The method for three-dimensional holographic display based on a holographic lens metasurface according to claim 1, wherein: Step 2 includes controlling the aspect ratio, height and / or rotation angle of the metasurface unit structure to produce different phases, and matching the phase map generated by the superposition calculation method for encoding.

6. The method for three-dimensional holographic display based on a holographic lens metasurface according to claim 1, wherein: The three-dimensional metasurface holographic reconstruction system in step 3 includes a laser, a first linear polarizer, a first quarter-wave plate, a metasurface, a microscope objective, a second quarter-wave plate, a second linear polarizer and a camera connected in sequence. The output light of the laser is converted into circularly polarized light after passing through the first linear polarizer and the first quarter-wave plate, exciting the metasurface of the encoded hologram, and the image is amplified by the microscope objective. The second quarter-wave plate and the second linear polarizer filter zero-order noise, and the camera receives the holographic image.

Images