Preparation equipment of optical film
By using a combination of grayscale mask and grating mask, the problem of difficulty in realizing the preparation of variable duty cycle optical diaphragm in traditional methods is solved, and efficient preparation of variable duty cycle optical diaphragm is achieved.
Patent Information
- Application Number
- CN202422514645.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-16
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2034-10-16
AI Technical Summary
The prior art is difficult to realize modulation of a variable duty cycle grating in the same region, and the traditional method cannot realize the preparation of a variable duty cycle optical diaphragm under the same grating period.
An optical diaphragm preparation device including a laser light source and a grayscale mask is used to form an uneven exposure dose through the uneven light transmittance of the grayscale mask, and combined with the interference effect of the grating mask, an optical diaphragm preparation with a variable duty cycle is achieved.
The variable duty cycle modulation of the optical diaphragm under the same grating period is realized, and the preparation efficiency and quality of the optical diaphragm are improved.
Smart Images
Figure CN223155259U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of light-emitting display, and particularly to a preparation device for an optical film. Background Art
[0002] A grating is a diffractive optical element with a periodic spatial structure or optical properties. The most prominent characteristic of a grating is dispersion, which can separate incident polychromatic light into a spectrum according to wavelength in the spatial propagation direction. In addition, gratings also have properties such as phase matching, beam splitting, and polarization. With the development of technology, the application of gratings is no longer limited to spectral analysis, and they have also been widely used in information processing fields such as optical waveguides, optical communications, metrology, and astronomy.
[0003] Currently, high-performance diffraction gratings generally require specific grating parameters, such as grating period, grating duty cycle, etc. The traditional method of adjusting the grating duty cycle is mainly achieved by changing the thickness of the photoresist layer exposed and the corresponding exposure dose, but this method cannot obtain a variable duty cycle grating in the same area. Summary of the Utility Model
[0004] An embodiment of this application provides a preparation device for an optical film.
[0005] An embodiment of this application provides a preparation device for an optical film. The preparation device for an optical film is used to expose a substrate to obtain an optical film. The preparation device for an optical film includes a laser light source and a gray-scale mask. The gray-scale mask is disposed on the optical path of the first light beam, and the light transmittance of the gray-scale mask is unevenly distributed. After the first light beam passes through the gray-scale mask, a second light beam for irradiating the substrate is formed, and the exposure dose formed by the second light beam on the substrate is unevenly distributed.
[0006] In some alternative embodiments, the preparation device for an optical film further includes a grating mask. The grating mask is disposed on the optical path of the second light beam. One side of the grating mask is used to be attached to the substrate. Under the diffraction effect of the grating mask, the second light beam forms a first sub-light beam and a second sub-light beam. The grating mask is used to make the first sub-light beam and the second sub-light beam irradiate the substrate simultaneously, and the first sub-light beam and the second sub-light beam interfere in the target processing area of the substrate to expose the substrate to generate an interference optical structure.
[0007] In some alternative embodiments, the gray-scale mask includes a first end region and a second end region at both ends, and the average light transmittance of the first end region is less than that of the second end region.
[0008] In some alternative embodiments, in the direction from the first end region to the second end region, the light transmittance of the gray-scale mask gradually decreases; or the light transmittance of the first end region is uniformly distributed, the light transmittance of the second end region is uniformly distributed, and the light transmittance of the first end region is less than that of the second end region; or the gray-scale mask further includes a middle region located between the first end region and the second end region, the light transmittance of the first end region is uniformly distributed, the light transmittance of the middle region is uniformly distributed, the light transmittance of the second end region is uniformly distributed; the light transmittance of the middle region is greater than that of the first end region and less than that of the second end region.
[0009] In some alternative embodiments, the gray-scale mask includes a central region and a peripheral region surrounding the central region, and the average light transmittance of the central region is greater than that of the peripheral region.
[0010] In some alternative embodiments, in the direction from the central region to the peripheral region, the light transmittance of the gray-scale mask gradually decreases; or the light transmittance of the central region is uniformly distributed, and the light transmittance of the peripheral region is uniformly distributed.
[0011] In some alternative embodiments, the preparation device of the optical film further includes a spatial light filter, a collimating lens, and a diaphragm. The spatial light filter is disposed between the laser light source and the gray-scale mask and is located on the optical path of the first light beam; the collimating lens is disposed between the spatial light filter and the gray-scale mask; the diaphragm is disposed between the collimating lens and the gray-scale mask.
[0012] In some alternative embodiments, the grating mask includes at least one of the following structures: surface relief grating, volume holographic grating, polarization volume grating.
[0013] In some alternative embodiments, the incident angle of the second light beam on the surface of the grating mask is θ i , θ i satisfies: θ i = arcsin(λ0 / 2Λ g ); where λ0 is the wavelength of the second light beam, and Λ g is the period of the grating mask.
[0014] In some alternative embodiments, the laser light source is an ultraviolet light source, and the preparation device of the optical film further includes an ultraviolet photoresist layer for coating on the substrate.
[0015] When the preparation equipment of the optical film provided by the embodiment of the present application is used, compared with the prior art, a laser light source emits a first light beam, and the first light beam forms a second light beam after passing through a grayscale mask. The light transmittance of the grayscale mask is unevenly distributed, so that the light field intensity distribution of the second light beam is uneven. When the second light beam irradiates the substrate, due to the uneven intensity distribution of the exposure field, the actual interference exposure doses at different positions on the substrate are different, thereby realizing variable duty cycle modulation or zoned duty cycle exposure during exposure under the same grating period, and realizing the preparation of an optical film with a variable duty cycle. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0017] Figure 1 FIG. is a simplified structural schematic diagram of a preparation device for an optical film provided by an embodiment of the present application.
[0018] Figure 2 is Figure 1 A simplified structural schematic diagram of an embodiment of the grayscale mask of the preparation device of the optical film shown.
[0019] Figure 3 is Figure 1 A simplified structural schematic diagram of another embodiment of the grayscale mask of the preparation device of the optical film shown.
[0020] Figure 4 is Figure 1 A simplified structural schematic diagram of still another embodiment of the grayscale mask of the preparation device of the optical film shown.
[0021] Figure 5 is Figure 1 A simplified structural schematic diagram of the grating mask and the grayscale mask of the preparation device of the optical film shown.
[0022] Reference numerals: 100, preparation device for an optical film; 10, laser light source; 20, grating mask; 30, grayscale mask; 32, first end region; 34, second end region; 36, middle region; 38, central region; 39, peripheral region; 50, spatial light filter; 70, collimating lens; 90, aperture; 200, optical film; 201, substrate. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] To enable those skilled in the art to better understand the solution of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of this application.
[0024] As used in the specification and claims, certain terms are used to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in names as a way to distinguish components, but rather use the difference in functions of components as the criterion for distinction. As mentioned throughout the specification and claims, "including" is an open-ended term and should be interpreted as "including but not limited to"; "substantially" means that those skilled in the art can solve technical problems within a certain error range and basically achieve the technical effect.
[0025] Please refer to Figure 1 , the embodiment of this application provides a preparation device 100 for an optical film, and the preparation device 100 for an optical film can be used to prepare an optical film.
[0026] The optical film is obtained by exposing a substrate 201, and the substrate 201 is a thin film made of a photosensitive material that responds to a specific wavelength. In this embodiment, the preparation device 100 for an optical film may include a laser light source 10 and a grayscale mask 30. The laser light source 10 is used to generate a first light beam A. The grayscale mask 30 is disposed on the optical path of the first light beam A, and the light transmittance of the grayscale mask 30 is unevenly distributed. After the first light beam A passes through the grayscale mask 30, a second light beam B for irradiating the substrate 201 is formed, and the exposure dose formed by the second light beam B on the substrate 201 is unevenly distributed.
[0027] The laser light source 10 emits the first light beam A, and the first light beam A forms the second light beam B after passing through the grayscale mask 30. The light transmittance of the grayscale mask 30 is unevenly distributed, so that the light field intensity distribution of the second light beam B is uneven. The second light beam B irradiates the substrate 201. Due to the uneven intensity distribution of the exposure field, the actual interference exposure doses at different positions on the substrate 201 are different, thereby realizing variable duty cycle modulation or zonal duty cycle exposure during exposure under the same grating period, and realizing the preparation of an optical film with a variable duty cycle.
[0028] The specific type of the laser light source 10 is not limited in this specification. For example, the laser light source 10 can adopt a linearly polarized laser, or an LED (light-emitting diode) light source, or a combination of other lasers and polarizers to collimate and homogenize the emitted light beam into a uniform light spot. In this embodiment, the laser light source 10 is an ultraviolet light source, and the first light beam A is a laser in the ultraviolet band. In this specification, the light rays emitted by the laser light source 10 are still considered to be "generated by the laser light source 10" after the optical path is changed by the optical device. For example, the reflected light rays obtained by reflecting the light rays emitted by the laser light source 10 by the reflector, or the refracted light rays obtained by refracting the light rays emitted by the laser light source 10 by the refractor are still considered to be "generated by the laser light source 10" and can be the first light beam A.
[0029] In this embodiment, the first light beam A is a laser in the ultraviolet band, and an ultraviolet photoresist layer can be coated on the substrate 201. The ultraviolet photoresist layer is a photosensitive material that can undergo chemical changes under ultraviolet light irradiation to achieve pattern transfer. The specific type of the ultraviolet photoresist layer is not limited in this specification. For example, the ultraviolet photoresist layer can include at least one of the following several types of photoresists: positive photoresist, negative photoresist, chemically amplified photoresist, extreme ultraviolet photoresist, metal-based extreme ultraviolet photoresist, inorganic photoresist, nano-oxide composite photoresist.
[0030] In this embodiment, the optical film preparation device 100 can further include a spatial light filter 50. The spatial light filter 50 is disposed between the laser light source 10 and the gray-scale mask 30 and is located on the optical path of the first light beam A. The spatial light filter 50 is used to filter out the high-frequency noise signals in the first light beam A, thereby ensuring the quality and stability of the output first light beam A. An optical filter is an instrument used for wavelength selection. It can select the required wavelength from numerous wavelengths, and the light other than this wavelength will be rejected. It can be used for wavelength selection, noise filtering of optical amplifiers, gain equalization, optical multiplexing / demultiplexing.
[0031] The optical film preparation device 100 can further include a collimating lens 70. The collimating lens 70 is disposed between the spatial light filter 50 and the gray-scale mask 30. The collimating lens 70 is used to collimate the light beam and convert the diverging light rays into parallel light. The specific type of the collimating lens 70 is not limited in this specification. For example, the collimating lens 70 can include at least one of the following structures: spherical lens, aspherical lens, cylindrical lens. The collimating lens 70 can adopt a reflective collimating lens or a transmissive collimating lens. In this embodiment, the collimating lens 70 adopts a transmissive collimating lens.
[0032] The preparation device 100 of the optical film can further include a diaphragm 90, and the diaphragm 90 is disposed between the collimating lens 70 and the gray-scale mask 30. The diaphragm 90 is used to control the passing range of the first light beam A, and controls the propagation direction or intensity of light by restricting the passing area of the light beam. A diaphragm refers to an entity that restricts the light beam in an optical system. It can be the edge or frame of a lens or a specially provided perforated screen. The functions of the diaphragm can be divided into two aspects: restricting the light beam or restricting the size of the field of view (imaging range).
[0033] In this embodiment, the spatial light filter 50, the collimating lens 70, and the diaphragm 90 are arranged in sequence on the optical path of the first light beam A emitted by the laser light source 10 to the gray-scale mask 30. The laser light source 10 emits the first light beam A. The spatial light filter 50 first filters out the high-frequency noise signals in the first light beam A. The filtered first light beam A is collimated by the collimating lens 70 to form a parallel light. The diaphragm 90 restricts the passing area of the parallel light to control the intensity and propagation position of the light, and finally makes the first light beam A propagate to the gray-scale mask 30 to generate the second light beam B with uneven light field.
[0034] The gray-scale mask 30 is located on the optical path of the first light beam A passing through the diaphragm 90. The first light beam A forms the second light beam B with uneven light field after passing through the gray-scale mask 30. The gray-scale mask is a kind of photomask. The gray-scale mask can provide variable light transmittance at different positions on the mask plane, and allows three-dimensional structures with different heights to be created by changing the exposure dose during the photolithography process. This specification does not limit the specific type of the gray-scale mask 30. For example, the gray-scale mask 30 can be a filter or a mask substrate with light-transmitting holes of different sizes distributed thereon. The gray value of each pixel point on the gray-scale mask 30 is between 0 and 255. When the gray value is 0, it is a black field. When the gray value increases, the exposure dose corresponding to the pixel point also increases. The exposure dose of each point is correlated with the gray value of the corresponding point. The exposure light field dose distribution after passing through the gray-scale mask 30 will change from a uniform light field distribution to a distribution correlated with the gray-scale mask.
[0035] In this embodiment, the gray-scale mask 30 may include a first end region 32 and a second end region 34 located at both ends. The average light transmittance of the first end region 32 may be less than the average light transmittance of the second end region 34. The light field of the second light beam B generated when the first light beam A passes through the first end region 32 is different from the light field of the second light beam B generated when the first light beam A passes through the second end region 34, forming a non-uniformly distributed exposure field, so as to facilitate the preparation of a variable duty cycle optical film.
[0036] The zoned design of the light transmittance of the grayscale mask 30 for different zones can achieve different duty cycle zoning. This specification does not limit the specific light transmittance distribution of the grayscale mask 30. For example, in the direction from the first end region 32 to the second end region 34, the light transmittance of the grayscale mask 30 gradually decreases. Or, as Figure 2 shown, the light transmittance of the first end region 32 is evenly distributed, the light transmittance of the second end region 34 is evenly distributed, and the light transmittance of the first end region 32 is less than that of the second end region 34. Or, as Figure 3 shown, the grayscale mask 30 further includes a middle region 36 located between the first end region 32 and the second end region 34. The light transmittance of the first end region 32 is evenly distributed, the light transmittance of the middle region 36 is evenly distributed, and the light transmittance of the second end region 34 is evenly distributed; the light transmittance of the middle region 36 is greater than that of the first end region 32 and less than that of the second end region 34.
[0037] In this application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of this application, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically and clearly defined.
[0038] In some other embodiments, please refer to Figure 4 , the grayscale mask 30 may include a central region 38 and a peripheral region 39 surrounding the outer periphery of the central region 38. The average light transmittance of the central region 38 is greater than that of the peripheral region 39. As an example, in the direction from the central region 38 to the outer peripheral region 38, the light transmittance of the grayscale mask 30 gradually decreases. As another example, the light transmittance of the central region 38 is evenly distributed, and the light transmittance of the peripheral region 39 is evenly distributed.
[0039] The gray level of the grayscale mask 30 is correlated with the exposure dose of the interference exposure field. The design of the gray level value of the grayscale mask 30 can be related to the exposure contrast curve of the ultraviolet photoresist layer to obtain a better gray level design.
[0040] Please also refer to Figure 1 and Figure 5, in this embodiment, the preparation device 100 of the optical film further includes a grating mask 20, and the grating mask 20 is used to generate interference light beams. The grating mask 20 is disposed on the optical path of the second light beam B, one side of the grating mask 20 is attached to the substrate 201, and the second light beam B forms a first sub-light beam B1 and a second sub-light beam B2 under the diffraction effect of the grating mask 20. The grating mask 20 is used to simultaneously irradiate the substrate 201 with the first sub-light beam B1 and the second sub-light beam B2, and the first sub-light beam B1 and the second sub-light beam B2 interfere in the target processing area of the substrate 201 to expose the substrate 201 to generate an interference optical structure. Among them, the "target processing area" can be understood as the area where the substrate 201 records the intensity distribution including the amplitude and phase information of the first sub-light beam B1 and the second sub-light beam B2.
[0041] The final working efficiency of the optical film can be adjusted by changing parameters such as the thickness of the substrate 201 used during exposure, the exposure time, and the optical power. Specifically, when the thickness of the substrate 201 decreases, the exposure time increases, and the optical power increases, the working efficiency of the optical film will be improved, and vice versa.
[0042] The light rays emitted by the laser light source 10 are diffracted by the grating mask 20 to form a first sub-light beam B1 and a second sub-light beam B2. Specifically, the incident expanded light beam will be divided into diffracted light beams propagating in multiple directions after passing through the grating mask 20. By optimizing the grating parameters of the grating mask 20 (such as adjusting parameters such as the period of the first grating mask 20, the duty cycle, or the morphology of the grating mask 20), two diffraction orders in the multiple diffracted light beams have a relatively high energy ratio. These two light beams are respectively used as the signal light and the reference light, that is, the above-mentioned first sub-light beam B1 and second sub-light beam B2.
[0043] The grating mask 20 includes at least three diffraction orders, namely the T0 order, the T-1 order, and the T+1 order. This specification does not limit the specific types of the first sub-light beam B1 and the second sub-light beam B2. For example, the first sub-light beam B1 can be the T0-order light, and the second sub-light beam B2 is the T-1-order light; or, the first sub-light beam B1 is the T+1-order light, and the second sub-light beam B2 is the T0-order light. In this embodiment, the incident angle of the second light beam B on the surface of the grating mask 20 is θ i , θ i satisfies:
[0044] θ i = arcsin(λ0 / 2Λ g )
[0045] In the formula, λ0 is the wavelength of the second light beam B, and Λ g is the period of the grating mask 20.
[0046] The second light beam B is at θ iThe incident grating mask 20 allows only the T0-level light and the T-1-level light to interfere, capable of forming an interference pattern with the same period as that of the grating mask 20, reducing the influence of background light on exposure. The first sub-beam B1 can be the T0-level light, and the second sub-beam B2 is the T-1-level light; or the first sub-beam B1 can be the T-1-level light, and the second sub-beam B2 is the T0-level light. By optimizing the grating parameters of the grating mask 20, a relatively high energy proportion is achieved for two diffraction orders among multiple diffracted beams, avoiding unnecessary superposition of the interference pattern. In this embodiment, the two diffracted beams (the first sub-beam B1 and the second sub-beam B2) generated by the grating mask 20 should have the same diffraction energy magnitude, resulting in a clearer contrast of the interference pattern formed thereby.
[0047] Preferably, the grating mask 20 is a diffraction grating on a transparent substrate, enabling the incident light to be diffracted with high efficiency after passing through the grating mask 20. This specification does not limit the specific type of the grating mask 20, and the grating mask 20 can include at least one of the following structures: surface relief grating, volume holographic grating, polarization volume grating. The surface of the surface relief grating consists of periodic microstructures and has no spatially varying refractive index. The surface relief grating solution has advantages such as a thin and light design structure, high design freedom, and relatively low cost in combination with nanoimprinting. The internal refractive index of the volume holographic grating is sinusoidally modulated, and its surface is smooth. The polarization volume grating is an optical element designed using the polarization characteristics of light, and it controls the incident light beam by regulating the spatial distribution of the liquid crystal optical axis.
[0048] When the optical film preparation device 100 provided in the embodiment of the present application is in use, the laser light source 10 emits the first beam A. The spatial light filter 50 first filters out the high-frequency noise signals in the first beam A. The filtered first beam A is collimated by the collimating lens 70 to form parallel light. The aperture 90 restricts the passing area of the parallel light to control the intensity and propagation position of the light, and finally enables the first beam A to propagate to the gray-scale mask 30. The first beam A forms the second beam B after passing through the gray-scale mask 30. The light transmittance of the gray-scale mask 30 is unevenly distributed, resulting in an uneven light field intensity distribution of the second beam B. The second beam B irradiates the substrate 201. Due to the uneven intensity distribution of the exposure field, the actual interference exposure doses at different positions on the substrate 201 are not the same, thereby achieving variable duty cycle modulation or zonal duty cycle exposure during exposure under the same grating period, and realizing the preparation of an optical film with a variable duty cycle.
[0049] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.
[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, rather than to limit them; although this application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of each embodiment of this application.
Claims
1. A preparation device for an optical film, characterized in that, The preparation device is used to expose a substrate to obtain an optical film. The preparation device includes: a laser light source for generating a first light beam; and a gray-scale mask disposed on the optical path of the first light beam. The light transmittance of the gray-scale mask is unevenly distributed. After the first light beam passes through the gray-scale mask, a second light beam for irradiating the substrate is formed, and the exposure dose formed by the second light beam on the substrate is unevenly distributed.
2. The manufacturing equipment of the optical film sheet according to claim 1, characterized in that, The preparation device for the optical film further includes a grating mask disposed on the optical path of the second light beam. One side of the grating mask is used to adhere to the substrate. Under the diffraction effect of the grating mask, the second light beam forms a first sub-light beam and a second sub-light beam. The grating mask is used to make the first sub-light beam and the second sub-light beam irradiate the substrate simultaneously, and the first sub-light beam and the second sub-light beam interfere in the target processing area of the substrate to expose the substrate to generate an interference optical structure.
3. The manufacturing equipment of the optical film according to claim 1, characterized in that, The gray-scale mask includes a first end region and a second end region at both ends. The average light transmittance of the first end region is less than that of the second end region.
4. The preparation device for the optical film according to claim 3, wherein in the direction from the first end region to the second end region, the light transmittance of the gray-scale mask gradually decreases; or the light transmittance of the first end region is evenly distributed, the light transmittance of the second end region is evenly distributed, and the light transmittance of the first end region is less than that of the second end region; or the gray-scale mask further includes a middle region between the first end region and the second end region. The light transmittance of the first end region is evenly distributed, the light transmittance of the middle region is evenly distributed, and the light transmittance of the second end region is evenly distributed; the light transmittance of the middle region is greater than that of the first end region and less than that of the second end region.
5. The manufacturing equipment of the optical film according to claim 1, characterized in that, The gray-scale mask includes a central region and a peripheral region surrounding the outer periphery of the central region. The average light transmittance of the central region is greater than that of the peripheral region.
6. The preparation device for the optical film according to claim 5, wherein in the direction from the central region to the outer peripheral region, the light transmittance of the gray-scale mask gradually decreases; or the light transmittance of the central region is evenly distributed, and the light transmittance of the peripheral region is evenly distributed.
7. The manufacturing equipment of the optical film sheet according to any one of claims 1 to 6, characterized in that The preparation device for the optical film further includes a spatial light filter, a collimating lens, and a diaphragm. The spatial light filter is disposed between the laser light source and the gray-scale mask and is located on the optical path of the first light beam; the collimating lens is disposed between the spatial light filter and the gray-scale mask; the diaphragm is disposed between the collimating lens and the gray-scale mask.
8. The manufacturing apparatus for an optical film according to claim 2, characterized in that, The grating mask includes at least one of the following structures: a surface relief grating, a volume holographic grating, and a polarization volume grating.
9. The manufacturing apparatus of the optical film according to claim 2, wherein The incident angle of the second light beam on the surface of the grating mask is θ i , θ i satisfies: θ i = arcsin(λ0 / 2Λ g ) where λ0 is the wavelength of the second beam, and Λ g is the period of the grating mask.
10. The manufacturing equipment of the optical film sheet according to claim 1, characterized in that, The laser light source is an ultraviolet light source, and the preparation device of the optical film further includes an ultraviolet photoresist layer for coating on the substrate.