WO2023231962A1 - Grating, and method and device for fabricating grating - Google Patents

Abstract

A grating (130), and a method and device (800) for fabricating a grating (130). The grating (130) comprises a cured colloid (110), wherein the cured colloid (110) comprises a particle aggregation area and a non-particle aggregation area, the particle aggregation area and the non-particle aggregation area are formed by applying an acting force (120) to the colloid (110) at intervals, that is, under the effect of the acting force (120), particles in the colloid (110) move to the areas where the acting force (120) is applied, so as to form the particle aggregation area, such that the refractive index of the particle aggregation area is greater than the refractive index of the non-particle aggregation area. In addition, since the selection range of the particles is relatively large, particles with a higher refractive index can be selected to participate in the fabrication of the grating (130), such that the difference between the refractive index of the particle aggregation area and the refractive index of the non-particle aggregation area is greater, that is, the refractive index contrast of the formed grating (130) is greater. Therefore, the grating (130), which is fabricated by means of the method and device for fabricating a grating (130), has a higher grating (130) refractive index contrast and a better optical performance.

Description

Grating, method and equipment for making grating

This application claims priority to the Chinese patent application submitted to the China Patent Office on June 1, 2022, with application number 202210620416.8 and the application title "A grating, a method and equipment for making a grating", the entire content of which is incorporated by reference in in this application.

Technical field

The present application relates to the field of optical technology, and more specifically, to a grating, a method and equipment for making a grating.

Background technique

Grating is a very widely used and important high-resolution dispersive optical element, which occupies a very important position in modern academic instruments. Among them, volume holographic gratings have the characteristics of high diffraction efficiency, easy manufacturing, and easy elimination of ghosts, and are an important development direction of gratings.

Existing volume holographic gratings are generally manufactured using holographic lithography technology. However, due to the limitations of holographic lithography materials, gratings made by holographic lithography technology have low grating refractive index contrast, that is, the refraction of different areas within the grating period. The rate difference is relatively low, which constrains the grating to obtain better optical performance.

Therefore, how to improve the grating refractive index contrast and provide gratings with better optical performance has become an urgent problem to be solved.

Contents of the invention

This application provides a grating, a grating manufacturing method and equipment, which can improve the grating refractive index contrast and obtain a grating with better optical performance.

The first aspect provides a method for making a grating, which includes: applying force at intervals on a colloid containing particles to aggregate the particles in the colloid in zones; solidifying the colloid to form a grating with a preset period, and the period of the grating is There is a corresponding relationship with the separation distance of the applied force.

Among them, the separation distance of the applied force can be understood as the interval at which the applied force is applied. By applying forces at different locations in the particle-containing colloid, gratings of different periods can be formed.

Alternatively, the interval at which the force is applied may be 1 nm to 10 μm.

The method of making gratings provided by this application can complete the production of gratings by applying force on the colloid at intervals and then solidifying the colloid. The production method is simple, and at the same time, there is a corresponding relationship between the period of the grating and the separation distance of the force. Gratings with different periods can be made by setting the intervals of the applied forces. In addition, the particle selection range is large, and particles with a higher refractive index can be selected to make gratings, thereby improving the grating refractive index contrast and obtaining gratings with better optical properties.

In connection with the first aspect, in some implementations of the first aspect, the grating includes a particle aggregation area and a non-particle aggregation area, and the number of particles in the non-particle aggregation area is less than the number of particles in the particle aggregation area.

It should be understood that the number of particles in the non-particle aggregation area in the grating is less than the number of particles in the particle aggregation area, so that the refractive index of the particle aggregation area is greater than the refractive index of the non-particle aggregation area, thereby forming a grating with a certain refractive index contrast.

In conjunction with the first aspect, in some implementations of the first aspect, the refractive index of the particle aggregation region is greater than the refractive index of the non-particle aggregation region.

It can be understood that the refractive index contrast of the grating is the difference between the refractive index of the particle gathering area and the refractive index of the non-particle gathering area.

The grating made by the method of making gratings provided in this application includes a particle gathering area and a non-particle gathering area, and the refractive index of the particle gathering area is greater than the refractive index of the non-particle gathering area. It can be selected by selecting a higher refractive index. The particles make gratings, which can improve the grating refractive index contrast and obtain gratings with better optical properties.

In conjunction with the first aspect, in some implementations of the first aspect, the difference between the refractive index of the particle aggregation region and the refractive index of the non-particle aggregation region is greater than or equal to 0.2.

Compared with gratings made by the prior art, the difference between the refractive index of the particle gathering area and the refractive index of the non-particle gathering area is greater than or equal to 0.2, that is, the grating refraction. The rate contrast is greater than or equal to 0.2, and the grating refractive index contrast can be further improved compared to the existing technology.

In conjunction with the first aspect, in some implementations of the first aspect, before applying force at intervals on the particle-containing colloid, the method further includes: laying the particle-containing colloid on the first surface of the substrate.

The method of making a grating provided by this application can make the surface of the colloid smoother by laying the colloid containing particles on the first surface of the substrate, so that the surface of the grating produced is smoother.

In conjunction with the first aspect, in some implementations of the first aspect, the method further includes: arranging a cover plate on a side of the particle-containing colloid away from the first surface.

The method of making a grating provided by this application forms a sandwich structure by arranging a base body or cover plates on both sides of the colloid, thereby avoiding contamination of the colloid when a force is exerted on the colloid.

Combined with the first aspect, in some implementations of the first aspect, applying force at intervals on the colloid containing particles to cause the particles in the colloid to aggregate in zones includes: applying force at intervals on one side of the colloid containing particles. , so that the particles in the colloid are aggregated in zones; or, forces are applied at intervals on both sides of the colloid containing particles, so that the particles in the colloid are aggregated in zones.

More specifically, in the embodiments of the present application, forces can be applied at intervals on the side of the colloid away from the matrix to cause the particles in the colloid to aggregate in zones; forces can also be applied at intervals on the side of the matrix away from the colloid, so that the particles in the colloid can aggregate in zones. The particles in the colloid aggregate in zones; forces can also be applied at intervals on the side of the colloid away from the matrix and on the side of the matrix away from the colloid, so that the particles in the colloid aggregate in zones.

The method for making gratings provided by this application can apply force on one side of the colloid or on both sides of the colloid; when a force is applied on one side of the colloid, the particles in the colloid can aggregate in zones, and A grating with a gradient structure can be formed; when force is applied on both sides of the colloid at the same time, the particles in the colloid can form a uniform grating structure, so that gratings can be produced in different ways according to actual needs.

In connection with the first aspect, in some implementations of the first aspect, the particle aggregation area corresponds to the area where the force is applied.

It should be understood that colloids have certain fluidity. When a force is exerted on the colloid, the particles in the colloid can move toward the area where the force is applied, that is, the particle aggregation area corresponds to the area where the force is applied.

Combined with the first aspect, in some implementations of the first aspect, the acting force is a non-contact induction force.

Combined with the first aspect, in some implementations of the first aspect, the non-contact induction force is magnetic force and the particles are magnetic particles; or the non-contact induction force is electrostatic force and the particles are charged particles.

Combined with the first aspect, in some implementations of the first aspect, the colloid is solidified to form a preset period The grating includes: when the force application time exceeds the preset time, the colloid is thermally cured or light cured to form a grating with a preset period, in which the particles in the colloid are fully gathered within the force application time.

Among them, the application time of the force can be judged based on the aggregation of particles in the colloid. Generally, the application time of this force is 1s to 10s.

It can be understood that when the applied force is larger, the particles gather faster and the force application time is shorter; when the applied force is smaller, the particles gather slower and the force application time is shorter. longer.

According to the method of making gratings provided by this application, when the time for applying force on the colloid exceeds a certain time, it can be judged that the particles in the colloid have fully gathered within the time when the force is applied, and then the colloid is cured (i.e., thermal curing). or light curing), a grating with a preset period can be formed. The method of making a grating is relatively simple and easy to operate. Furthermore, by selecting particles with different refractive indexes, gratings with different refractive index contrasts can be produced.

Combined with the first aspect, in some implementations of the first aspect, when the force is magnetic force, the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.

It should be understood that the magnitude of the magnetic force can be determined based on actual conditions. For example, the magnitude of the magnetic force can be determined based on factors such as the composition of the colloid and the composition of the particles.

In some embodiments, if other factors such as particle composition are the same, the greater the viscosity of the colloid, the greater the magnetic force that needs to be applied; when the viscosity of the colloid is smaller, the smaller the magnetic force that needs to be applied.

In some embodiments, if other factors such as the colloid composition are the same, the smaller the particle's induction of the magnetic field, the greater the magnetic force that needs to be applied; when the particle's induction of the magnetic field is greater, the smaller the magnetic force that needs to be applied.

In connection with the first aspect, in some implementations of the first aspect, the colloid may be a material with thermal curing or light curing, for example, polymethylmethacrylate PMMA, polydimethylsiloxane PDMS.

Combined with the first aspect, in some implementations of the first aspect, the above-mentioned particles may be any of the following: ferric oxide Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O _4. Nickel.

In the method of making a grating provided in this application, the particle-containing colloid can be made by mixing the colloid and particles of the above-mentioned materials. Since the particles (such as Fe ₃ O ₄ ) can be affected by magnetic force or electrostatic force, when When a magnetic force or electrostatic force is applied to a colloid containing particles, the particles (such as Fe ₃ O ₄ ) in the colloid can move in the direction of the applied magnetic force or electrostatic force, thereby forming a grating with a certain period.

In a second aspect, a grating is provided, including a cured colloid. The cured colloid includes a particle aggregation area and a non-particle aggregation area. The particle aggregation area and the non-particle aggregation area are formed by applying forces at intervals on the colloid. The particle aggregation areas Zone corresponds to the area where the force is applied.

Combined with the second aspect, in some implementations of the second aspect, the number of particles in the non-particle aggregation area is less than the number of particles in the particle aggregation area.

In conjunction with the second aspect, in some implementations of the second aspect, the refractive index of the particle aggregation region is greater than the refractive index of the non-particle aggregation region.

The grating provided by this application includes a solidified colloid. The number of particles in the non-particle aggregation area in the solidified colloid is less than the number of particles in the particle aggregation area, so that the refractive index of the particle aggregation area is greater than the refractive index of the non-particle aggregation area, thereby forming A grating with a certain refractive index contrast. In addition, due to the large selection range of particles, when particles with a higher refractive index are selected to make a grating, the difference between the refractive index of the particle gathering area and the refractive index of the non-particle gathering area is greater, that is, the formed grating refraction The rate contrast is greater. The resulting grating has better optical properties.

Combined with the second aspect, in some implementations of the second aspect, the difference between the refractive index of the particle aggregation region and the refractive index of the non-particle aggregation region is greater than or equal to 0.2.

It should be understood that the refractive index contrast of the grating is the difference between the refractive index of the particle-concentrated region and the refractive index of the non-particle-concentrated region.

The refractive index contrast of the grating provided by this application can reach 0.2 and above. Compared with the grating produced by the existing technology, it has better grating refractive index contrast and optical performance.

Combined with the second aspect, in some implementations of the second aspect, the acting force is a non-contact induction force.

Combined with the second aspect, in some implementations of the second aspect, the non-contact induction force is magnetic force and the particles are magnetic particles; or the non-contact induction force is electrostatic force and the particles are charged particles.

Combined with the second aspect, in some implementations of the second aspect, the acting force is magnetic force, the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.

Combined with the second aspect, in some implementations of the second aspect, the colloid is polymethylmethacrylate PMMA and/or polydimethylsiloxane PDMS.

Combined with the second aspect, in some implementations of the second aspect, the particles are any one of the following: ferric oxide Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , Nickel.

It should be understood that the gratings produced in the embodiments of the present application can be used in augmented reality AR optical waveguides, in lasers, and in automotive head-up displays (HUDs).

A third aspect provides a device, which includes the grating of the second aspect and any implementation thereof.

In a fourth aspect, a device for making gratings is provided, including: a force application module and a curing module. The force application module is used to apply force at intervals on a colloid containing particles so as to aggregate the particles in the colloid in zones; The curing module is used to solidify the colloid to form a grating with a preset period. There is a corresponding relationship between the period of the grating and the separation distance of the applied force.

Combined with the fourth aspect, in some implementations of the fourth aspect, the grating includes a particle aggregation area and a non-particle aggregation area, and the number of particles in the non-particle aggregation area is less than the number of particles in the particle aggregation area.

In connection with the fourth aspect, in some implementations of the fourth aspect, the refractive index of the particle aggregation region is greater than the refractive index of the non-particle aggregation region.

Combined with the fourth aspect, in some implementations of the fourth aspect, the difference between the refractive index of the particle aggregation area and the refractive index of the non-particle aggregation area is greater than or equal to 0.2.

Combined with the fourth aspect, in some implementations of the fourth aspect, the particle-containing colloid is laid on the first surface of the substrate.

In conjunction with the fourth aspect, in some implementations of the fourth aspect, a cover plate is provided on the first surface, and the cover plate is in contact with the colloid and completely covers the colloid.

Combined with the fourth aspect, in some implementations of the fourth aspect, the force application module is also used to: apply force at intervals on one side of the colloid containing particles to cause the particles in the colloid to aggregate in zones; or, on the colloid containing particles, Force is exerted on both sides of the colloid to cause the particles in the colloid to aggregate in zones.

In combination with the fourth aspect, in some implementations of the fourth aspect, the particle aggregation area corresponds to the area where the force is applied.

Combined with the fourth aspect, in some implementations of the fourth aspect, the acting force is a non-contact induction force.

Combined with the fourth aspect, in some implementations of the fourth aspect, the non-contact induction force is magnetic force and the particles are magnetic particles; or the non-contact induction force is electrostatic force and the particles are charged particles.

Combined with the fourth aspect, in some implementations of the fourth aspect, the curing module is also used to: when the force application time exceeds a preset time, thermally solidify or light-cure the colloid to form a grating with a preset period, where , the particles in the colloid are fully aggregated within the time when the force is applied.

Combined with the fourth aspect, in some implementations of the fourth aspect, the force is magnetic force, the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.

Combined with the fourth aspect, in some implementations of the fourth aspect, the colloid is polymethylmethacrylate PMMA and/or polydimethylsiloxane PDMS.

Combined with the fourth aspect, in some implementations of the fourth aspect, the particles are any one of the following: ferric oxide Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , Nickel.

Description of the drawings

FIG. 1 is a schematic flow chart of a method for making a grating provided by an embodiment of the present application.

FIG. 2 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application.

FIG. 3 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application.

FIG. 4 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application.

FIG. 5 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application.

FIG. 6 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application.

Figure 7 is a schematic diagram of a grating provided by an embodiment of the present application.

Figure 8 is a schematic diagram of an equipment for making gratings provided by an embodiment of the present application.

Detailed ways

The technical solutions in this application will be described below with reference to the accompanying drawings.

The terminology used in the following examples is for the purpose of describing specific embodiments only and is not intended to limit the application. As used in the specification and appended claims of this application, the singular expressions "a," "an," "the" and "the" are intended to also include, for example, "one or more" form of expression unless its context clearly indicates otherwise. Reference in this specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Therefore, the phrases "in one embodiment", "in some embodiments", "in other embodiments", "in other embodiments", etc. appearing in different places in this specification are not necessarily References are made to the same embodiment, but rather to "one or more but not all embodiments" unless specifically stated otherwise. The terms “including,” “includes,” “having,” and variations thereof all mean “including but not limited to,” unless otherwise specifically emphasized.

In the embodiments of the present application, “first”, “second” and various numerical numbers are only used for convenience of description and are not used to limit the scope of the embodiments of the present application. The sequence numbers of each process below do not mean the order of execution. The execution order of each process should be determined by its functions and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application. In addition, in the embodiments of the present application, words such as “110”, “120”, and “130” are only used for convenience of description and do not limit the order of execution of steps. In the embodiments of this application, descriptions such as "when", "if" and "if" all mean that the device will perform corresponding processing under certain objective circumstances. They do not limit the time, and do not require the device to be in There must be judgment actions during implementation, and it does not mean that there are other restrictions.

It should be noted that in this application, words such as “exemplary” or “for example” are used to represent examples, illustrations or explanations. Any embodiment or design described herein as "exemplary" or "such as" is not intended to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the words "exemplary" or "such as" is intended to present the concept in a concrete manner.

As mentioned in the background art, grating is a very widely used and important high-resolution dispersive optical element. It occupies a very important position in modern advanced learning instruments. Gratings can include surface relief gratings and volume phase holographic gratings (volume phase holographic grating, VPHG). Surface relief gratings have regular engraved lines and exquisite surfaces; volume phase holographic gratings are also called volume holographic gratings. This grating has very good Optical properties and design flexibility, superior stability and consistency. Volume holographic gratings are therefore ideally suited for laser pulse compression, spectrometry, optical coherence tomography, and astronomy.

Compared with surface relief gratings, volume holographic gratings have the characteristics of high diffraction efficiency, easy manufacturing, and easy elimination of ghosts. They are an important development direction of gratings. Volume holographic grating is an optical element with a periodic structure. It usually interferes directly inside the micron-thick photosensitive polymer film through double-beam holographic exposure to form light and dark interference fringes, thereby causing the refractive index period inside the material. sexual changes. This period is generally a nanoscale grating structure, which is of the same order as the wavelength of visible light, so the light can be effectively modulated and the direction of light transmission is changed by diffracting the incident light. Volume holographic gratings are commonly used in augmented reality (AR) optical waveguides. In the application of AR optical waveguides, light modulation is achieved through volume holographic grating diffraction, allowing the displayed content to be directly projected into the human eye.

Existing volume holographic gratings are generally manufactured using holographic lithography technology. In holographic lithography technology, laser light is emitted and transmitted through different optical paths to form interference on the substrate and generate interference fringes, thereby exposing the holographic photosensitive material. The exposed holographic photosensitive material absorbs photons and produces a cross-linking reaction, thereby changing the refractive index and obtaining a grating with periodic changes in refractive index. However, due to the limitations of holographic lithography materials, the gratings made by holographic lithography technology have a low grating refractive index contrast, that is, the refractive index differences in different areas within the grating period are low, which constrains the grating to obtain better results. Optical properties.

Therefore, the embodiments of the present application provide a grating, a method and equipment for making a grating, which can improve the grating refractive index contrast and provide a grating with better optical performance.

FIG. 1 is a schematic flow chart of a method for making a grating provided by an embodiment of the present application. Figure 1 shows a side view of a grating. The method may include steps 101 to 104. The specific steps are as follows:

101. Obtain particle-containing colloid 110.

It should be understood that the particle-containing colloid 110 can be obtained by adding particles to the colloid and mixing and stirring. Therefore, it can be understood that the particle-containing colloid 110 has a certain fluidity, and the colloid can be liquid or semi-liquid. .

Wherein, the material of the colloid is a curable material (a material that can be thermally cured or light-cured), that is, the colloid can form a solid colloid (ie, a grating) through thermal curing or light-curing. For example, the colloid may be made of materials such as polyethylene (PE), polypropylene (PP), polystyrene (PS), etc.

Alternatively, the colloid may be polymethyl methacrylate (PMMA) and/or polydimethylsiloxane (PDMS).

It should be understood that the particles contained in the colloid may be magnetic particles or other charged particles. When a corresponding magnetic force or a corresponding electrostatic force is applied to the colloid, the magnetic particles or charged particles in the colloid can move with a certain displacement in the colloid.

Alternatively, the particles may be any of the following: ferric oxide Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , and nickel Ni, which is not limited in this application.

That is to say, the particle-containing colloid 110 can be a mixture of colloid and particles. Since the particles (such as Fe ₃ O ₄ ) can be affected by magnetic force or electrostatic force, when magnetic force or electrostatic force is exerted on the particle-containing colloid, When electrostatic force is applied, the particles in the colloid (such as Fe ₃ O ₄ ) can move in the direction of the magnetic force or electrostatic force, thus forming a certain circumference. period raster.

It should also be understood that the particle-containing colloid 110 has a certain thickness, and the thickness can be set according to actual needs. For example, the thickness of the particle-containing colloid 110 can be set to 5 μm to 15 μm, which is not limited in this application.

102-103. Apply force 120 at intervals on one side of the particle-containing colloid 110 to cause the particles in the colloid to aggregate in zones.

Specifically, when a force 120 is applied at intervals on one side of the particle-containing colloid 110, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown at 130 in Figure 1.

When a force 120 is applied at intervals on one side of the particle-containing colloid 110 along the thickness direction, the particles on the side closer to the force 120 will move toward the position where the force is applied under the action of the force; Particles on the side farther away from the force 120 may remain motionless. In this case, the particles in the colloid form a gradient structure along the thickness direction, thereby forming a gradient grating.

It should be understood that the force 120 can be a non-contact induction force, which can be understood as having an influence on the object without direct contact with the object. For example, the force 120 can include magnetic force or electrostatic force.

In some embodiments, the force 120 can be a magnetic force, and the particles in the colloid can be magnetic particles, that is, the magnetic particles in the colloid can move toward the position where the magnetic force is exerted under the influence of the magnetic force.

In other embodiments, the force 120 may be an electrostatic force, and the particles in the colloid may be charged particles. That is, the charged particles in the colloid may move toward the position where the electrostatic force is applied under the action of the electrostatic force. .

Optionally, when the force is magnetic force, the magnitude of the magnetic force may be 0.001T to 10T, and T is the magnetic force unit Tesla.

It should be understood that the magnitude of the magnetic force can be determined based on actual conditions. For example, the magnitude of the magnetic force can be determined based on factors such as the composition of the colloid and the composition of the particles.

In some embodiments, if other factors such as particle composition are the same, the greater the viscosity of the colloid, the greater the magnetic force that needs to be applied; when the viscosity of the colloid is smaller, the smaller the magnetic force that needs to be applied.

In other embodiments, if other factors such as the colloid composition are the same, the smaller the particle's induction of the magnetic field, the greater the magnetic force that needs to be applied; when the particle's induction of the magnetic field is greater, the smaller the magnetic force that needs to be applied.

Optionally, the force 120 exerted at this interval may be a uniform force. Under the action of the force 120, the particles in the colloid can form a particle aggregation area and a non-particle aggregation area, and the number of particles in the non-particle aggregation area is less than the number of particles in the particle aggregation area. The refractive index of the particle gathering area of the thus formed grating should be greater than the refractive index of the non-particle gathering area.

It should be understood that this region of particle accumulation corresponds to the region where force 120 is exerted. That is, when the force 120 is applied to the colloid 110 containing particles, the particles in the colloid can move toward the area where the force is applied, so that the particle aggregation area corresponds to the area where the force 120 is applied.

Optionally, the difference between the refractive index of the particle aggregation area and the refractive index of the non-particle aggregation area (ie, the refractive index contrast) can be as high as 0.2 and above. Compared with the grating refractive index contrast obtained by the existing technology, the contrast ratio is about 0.05 to 0.1 higher, which can break through the refractive index bottleneck of the holographic grating and achieve a breakthrough in the refractive index modulation coefficient.

104. The particle-containing colloid 110 is solidified to form a grating 130 with a preset period, and there is a corresponding relationship between the period of the grating 130 and the separation distance of the force 120.

Specifically, after the particle-containing colloid 110 is processed in steps 102 and 103, the particles in the colloid achieve partition aggregation and can form a gradient structure. When the particles in the colloid are fully aggregated, the particles that have been processed in steps 102 and 103 The final colloid is cured to form a grating 130 with a preset period.

Optionally, when the force application time exceeds the preset time, the colloid is thermally cured or light cured to form a grating with a preset period, in which the particles in the colloid are fully aggregated within the application time of the force 120 .

It should be understood that the application time of the force can be judged based on the aggregation of particles in the colloid. Generally, the application time of the force is 1s to 10s.

It can be understood that when the applied force is larger, the particles gather faster and the force application time is shorter; when the applied force is smaller, the particles gather slower and the force application time is shorter. longer.

It should be understood that in the grating structure formed by solidification, there is a corresponding relationship between the period of the grating of the grating structure and the interval of the applied force. That is to say, the interval at which the force is applied can be set according to the period of the grating that needs to be made. The interval at which the applied force is applied can be understood as the interval distance at which the applied force is applied, and the interval at which the applied force is applied is 1 nm to 10 μm.

The grating structure produced through steps 101 to 104 can form a gradient grating structure because the force is only applied to one side of the colloid, and the number of particles in the particle aggregation area of the formed grating structure is greater than that in the non-particle aggregation area. The number of particles in the area, that is, the refractive index of the particle aggregation area is greater than the refractive index of the non-particle aggregation area (or an area with fewer particles), so that a grating with a certain refractive index contrast can be formed. In addition, due to the large selection range of particles, when particles with a higher refractive index are selected to make a grating, the difference between the refractive index of the particle aggregation area and the refractive index of the non-particle aggregation area will also be greater, resulting in a grating Features higher grating refractive index contrast and better optical performance.

FIG. 2 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application. Figure 2 shows a side view of the grating. The method may include steps 201 to 204. The specific steps are as follows:

201. Obtain the particle-containing colloid 110, and lay the particle-containing colloid 110 on the first surface of the substrate 111.

It should be understood that the matrix 111 can provide mechanical support for the particle-containing colloid 110. The material of the matrix 111 can be, for example, metal materials (such as copper, steel, iron, aluminum), glass, organic materials (such as resin), etc. This application is This is not a limitation.

For other contents of this step, please refer to step 101 and will not be described again here.

202-203, apply force 120 at intervals on one side of the particle-containing colloid 110 to aggregate the particles in the colloid in zones.

Optionally, when a force 120 is applied at intervals on the side of the particle-containing colloid 110 away from the matrix 111, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown in 130.

Optionally, when a force is applied at intervals on the side of the matrix 111 away from the colloid 110, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown in 130.

For other details of this step, please refer to steps 102-103, which will not be described again here.

204. Solidify the particle-containing colloid 110 to form a grating 130 with a preset period. There is a corresponding relationship between the period of the grating and the separation distance of the applied force.

For the specific content of this step, please refer to step 104, which will not be described again here.

The method for making a grating provided by the embodiment of the present application lays the colloid containing particles on the first surface of the substrate, so that the surface of the colloid can be made smoother, so that the surface of the grating produced is smoother. Furthermore, by applying force on one side of the colloid, a gradient grating structure can be obtained. Furthermore, by selecting particles with a higher refractive index to make gratings, the resulting gratings have higher refractive index contrast and better optical properties.

FIG. 3 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application. Figure 3 shows a side view of the grating. The method may include steps 301 to 304. The specific steps are as follows:

301. Obtain the particle-containing colloid 110 and lay the particle-containing colloid 110 on the first surface of the substrate 111. In addition, a cover plate 112 is provided on the side of the particle-containing colloid 110 away from the first surface.

It should be understood that the matrix 111 can provide mechanical support for the particle-containing colloid 110 . The materials of the base 111 and the cover 112 may be, for example, metal materials (such as copper, steel, iron, aluminum), glass, organic materials (such as resin), etc., which are not limited in this application.

It should also be understood that the base 111 and the cover 112 are used together to form a sandwich structure with the particle-containing colloid 110, that is, the base 111, the particle-containing colloid 110 and the cover 112 form a sandwich structure, thereby preventing the particle-containing colloid from being When force is applied on 110, the colloid is contaminated and a purer grating is obtained.

For other contents of this step, please refer to step 101 and will not be described again here.

302-303, apply force 120 at intervals on one side of the particle-containing colloid 110 to aggregate the particles in the colloid in zones.

Optionally, when a force 120 is applied at intervals on the side of the particle-containing colloid 110 away from the matrix 111, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown in 130.

Optionally, when a force is applied at intervals on the side of the matrix 111 away from the colloid 110, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown in 130.

For other details of this step, please refer to steps 102-103, which will not be described again here.

304. The particle-containing colloid 110 is solidified to form a grating 130 with a preset period. There is a corresponding relationship between the period of the grating and the separation distance of the applied force.

For the specific content of this step, please refer to step 104, which will not be described again here.

The method of making a grating provided in the embodiment of the present application forms a sandwich structure by arranging a base body or a cover plate on both sides of the colloid, thereby avoiding contamination of the colloid when a force is exerted on the colloid. Furthermore, by applying force on one side of the colloid, a gradient grating structure can be obtained. Furthermore, by selecting particles with a higher refractive index to make gratings, the resulting gratings have higher refractive index contrast and better optical properties.

FIG. 4 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application. Figure 4 shows a side view of the grating. The method may include steps 401 to 404. The specific steps are as follows:

401. Obtain particle-containing colloid 110.

For details of this step, please refer to step 101, which will not be described again here.

402-403, apply forces 120 at intervals on both sides of the particle-containing colloid 110 to cause the particles in the colloid to aggregate in zones.

Specifically, when the force 120 is applied at intervals on both sides of the particle-containing colloid 110, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown at 140 in Figure 4.

When a force 120 is applied at intervals on both sides of the particle-containing colloid 110 along the thickness direction, the particles on both sides of the particle-containing colloid 110 will move toward the position where the force is applied under the action of the force 120 movement, therefore, a uniformly structured grating can be formed.

For other details of this step, please refer to steps 102-103, which will not be described again here.

404. The particle-containing colloid 110 is solidified to form a grating 140 with a preset period. There is a corresponding relationship between the period of the grating and the separation distance of the applied force.

For other contents of this step, please refer to step 104 and will not be described again here.

The grating structure obtained through steps 401 to 404 can form a uniform grating structure due to the uniform force exerted on both sides of the colloid at intervals, and the number of particles in the particle aggregation area in the formed grating structure is greater than that in the non-particle aggregation area. The number of particles, that is, the refractive index of the particle aggregation area is greater than the refractive index of the non-particle aggregation area (or an area with fewer particles), so that a grating with a certain refractive index contrast can be formed. In addition, due to the large selection range of particles, when selecting fold When gratings are made from particles with higher refractive index, the resulting gratings have higher refractive index contrast and better optical properties.

FIG. 5 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application. Figure 5 shows a side view of the grating. The method may include steps 501 to 504. The specific steps are as follows:

501. Obtain the particle-containing colloid 110, and lay the particle-containing colloid 110 on the first surface of the substrate 111.

It should be understood that the matrix 111 can provide mechanical support for the particle-containing colloid 110. The material of the matrix 111 can be, for example, metal materials (such as copper, steel, iron, aluminum), glass, organic materials (such as resin), etc. This application is This is not a limitation.

For other contents of this step, please refer to step 101 and will not be described again here.

502-503, apply forces 120 at intervals on both sides of the particle-containing colloid 110 to cause the particles in the colloid to aggregate in zones.

Specifically, when the force 120 is applied at intervals on both sides of the particle-containing colloid 110, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown in 140.

When a force 120 is applied at intervals on both sides of the particle-containing colloid 110 along the thickness direction, the particles on both sides of the particle-containing colloid 110 will move toward the position where the force is applied under the action of the force 120 movement, therefore, a uniformly structured grating can be formed.

For other details of this step, please refer to steps 102-103, which will not be described again here.

504. The particle-containing colloid 110 is solidified to form a grating 140 with a preset period. There is a corresponding relationship between the period of the grating and the separation distance of the applied force.

For the specific content of this step, please refer to step 104, which will not be described again here.

The method for making a grating provided by the embodiment of the present application lays the colloid containing particles on the first surface of the substrate, so that the surface of the colloid can be made smoother, so that the surface of the grating produced is smoother. In addition, since uniform forces are applied to both sides of the colloid simultaneously and at intervals, a uniform grating structure can be obtained. Furthermore, the grating made by selecting particles with higher refractive index has higher grating refractive index contrast and better optical performance.

FIG. 6 is a schematic flow chart of another method for making a grating provided by an embodiment of the present application. Figure 6 shows a side view of the grating. The method may include steps 601 to 604. The specific steps are as follows:

601. Obtain the particle-containing colloid 110, lay the particle-containing colloid 110 on the first surface of the substrate 111, and set a cover 112 on the side of the particle-containing colloid 110 away from the first surface.

It should be understood that the matrix 111 can provide mechanical support for the particle-containing colloid 110 . The materials of the base 111 and the cover 112 may be, for example, metal materials (such as copper, steel, iron, aluminum), glass, organic materials (such as resin), etc., which are not limited in this application.

It should also be understood that the base 111 and the cover 112 are used together to form a sandwich structure with the particle-containing colloid 110, that is, the base 111, the particle-containing colloid 110 and the cover 112 form a sandwich structure, thereby preventing the particle-containing colloid from being When force is applied on 110, the colloid is contaminated and a purer grating is obtained.

For other contents of this step, please refer to step 101 and will not be described again here.

602-603: Apply forces 120 at intervals on both sides of the particle-containing colloid 110 to cause the particles in the colloid to aggregate in zones.

Specifically, when the force 120 is applied at intervals on both sides of the particle-containing colloid 110, the particles in the colloid achieve zone aggregation under the action of the force 120, forming a structure as shown in 140.

When a force 120 is applied at intervals on both sides of the particle-containing colloid 110 along the thickness direction, the particles on both sides of the particle-containing colloid 110 will move toward the position where the force is applied under the action of the force 120 mobile, therefore, can to form a uniformly structured grating.

For other details of this step, please refer to steps 102-103, which will not be described again here.

604. The particle-containing colloid 110 is solidified to form a grating 140 with a preset period. There is a corresponding relationship between the period of the grating and the separation distance of the applied force.

For the specific content of this step, please refer to step 104, which will not be described again here.

The method of making a grating provided in the embodiment of the present application forms a sandwich structure by arranging a base body or a cover plate on both sides of the colloid, thereby avoiding contamination of the colloid when a force is exerted on the colloid. In addition, since uniform forces are applied to both sides of the colloid simultaneously and at intervals, a uniform grating structure can be obtained. Furthermore, the grating made by selecting particles with higher refractive index has higher grating refractive index contrast and better optical performance.

Figure 7 is a schematic diagram of a grating provided by an embodiment of the present application. Figure 7 shows a top view of the grating.

Through any method of making a grating shown in FIGS. 1 to 6 , a top view of the grating structure as shown in FIG. 7 can be obtained. The grating produced by any of the grating producing methods shown in Figures 1 to 3 has a gradient structure. A more uniform grating structure can be obtained by using any of the methods of making gratings shown in FIGS. 4 to 6 .

The grating shown in Figure 7 may include a cured colloid (ie, a colloid obtained by a curing process). The colloid includes a particle aggregation area and a non-particle aggregation area. The particle aggregation area and the non-particle aggregation area are formed by applying effects on the colloid at intervals. Formed by a force, the particle accumulation area corresponds to the area where the force is applied.

It should be understood that the number of particles in the non-particle aggregation region is less than the number of particles in the particle aggregation region, and the refractive index of the particle aggregation region is greater than the refractive index of the non-particle aggregation region.

Optionally, the difference between the refractive index of the particle-aggregated region and the refractive index of the non-particle-aggregated region (ie, the refractive index contrast) can be as high as 0.2 or more. Compared with the grating refractive index contrast obtained by the existing technology, the contrast ratio is about 0.05 to 0.1 higher, which can break through the refractive index bottleneck of the holographic grating and achieve a breakthrough in the refractive index modulation coefficient.

Optionally, the force is a non-contact induction force. Optionally, when the non-contact induction force is magnetic force, the particles are magnetic particles; when the non-contact induction force is electrostatic force, the particles are charged particles.

Optionally, the acting force is magnetic force, and the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.

Optionally, the colloid is polymethylmethacrylate PMMA and/or polydimethylsiloxane PDMS.

Optionally, the particles are any one of the following: ferric oxide Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , and nickel Ni.

It should be understood that the grating made by the embodiment of the present application can be used in an augmented reality AR optical waveguide, in a laser, and in a car's head-up display (HUD).

The grating obtained by the method provided in the embodiments of the present application can break through the limitation of the refractive index of the holographic grating and obtain higher grating refractive index contrast and better optical performance.

Figure 8 is a schematic diagram of an equipment for making gratings provided by an embodiment of the present application.

The device 800 for making gratings includes a force application module 810 and a curing module 820. The force application module 810 is used to apply force at intervals on the colloid containing particles to aggregate the particles in the colloid in zones; the curing module 820 is used to For solidifying the colloid to form a grating with a preset period, there is a corresponding relationship between the period of the grating and the separation distance of the applied force.

Optionally, the grating includes a particle aggregation area and a non-particle aggregation area, and the number of particles in the non-particle aggregation area is less than the number of particles in the particle aggregation area.

Optionally, the refractive index of the particle-aggregated region is greater than the refractive index of the non-particle-aggregated region.

Optionally, the difference between the refractive index of the particle aggregation area and the refractive index of the non-particle aggregation area is greater than or equal to 0.2.

Optionally, the particle-containing colloid is laid on the first surface of the substrate.

Optionally, a cover plate is provided on a side of the particle-containing colloid away from the first surface.

Optionally, the particle accumulation area corresponds to the area where the force is applied.

Optionally, the force application module 810 is also used to: apply force at intervals on one side of the colloid containing particles to aggregate the particles in the colloid in zones; or, apply forces at intervals on both sides of the colloid containing particles, In order to make the particles in the colloid aggregate in zones. That is to say, a force is applied at intervals on the side of the colloid away from the matrix to cause the particles in the colloid to aggregate in zones; or, a force is applied at intervals on the side of the matrix away from the colloid to cause the particles in the colloid to aggregate in zones; or, Apply forces at intervals on the side of the colloid away from the matrix and on the side of the matrix away from the colloid at intervals to cause the particles in the colloid to aggregate in zones.

Optionally, the force is a non-contact induction force. Alternatively, the non-contact induction force is magnetic force, and the particles are magnetic particles; or, the non-contact induction force is electrostatic force, and the particles are charged particles.

Optionally, the curing module 820 is also used to: when the force application time exceeds the preset time, the colloid is thermally cured or light cured to form a grating with a preset period, wherein the particles in the colloid are Fully gathered inside.

Optionally, the acting force is magnetic force, and the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.

Optionally, the colloid is polymethylmethacrylate PMMA and/or polydimethylsiloxane PDMS.

Optionally, the particles are any one of the following: ferric oxide Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , and nickel Ni.

In addition, this application also provides a device, which device includes a grating made by any of the above methods, or includes any of the above grating structures.

Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented with electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each specific application, but such implementations should not be considered beyond the scope of this application.

The above are only specific embodiments of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application. should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims (33)

1. A method of making gratings, characterized by including:

   Apply force at intervals on the colloid containing particles to cause the particles in the colloid to aggregate in zones;

   The colloid is solidified to form a grating with a preset period, and there is a corresponding relationship between the period of the grating and the separation distance of the force.
2. The method of claim 1, wherein the grating includes a particle aggregation area and a non-particle aggregation area, and the number of particles in the non-particle aggregation area is less than the number of particles in the particle aggregation area.
3. The method of claim 2, wherein the refractive index of the particle aggregation region is greater than the refractive index of the non-particle aggregation region.
4. The method according to claim 2 or 3, characterized in that the difference between the refractive index of the particle aggregation area and the refractive index of the non-particle aggregation area is greater than or equal to 0.2.
5. The method according to any one of claims 1 to 4, characterized in that, before applying force at intervals on the colloid containing particles, the method further includes:

   The particle-containing colloid is laid on the first surface of the substrate.
6. The method of claim 5, further comprising:

   A cover plate is provided on the side of the particle-containing colloid away from the first surface.
7. The method according to any one of claims 1 to 6, characterized in that applying force at intervals on the colloid containing particles to cause the particles in the colloid to aggregate in zones includes:

   Apply force at intervals on one side of the particle-containing colloid to cause the particles in the colloid to aggregate in zones; or,

   Forces are applied at intervals on both sides of the particle-containing colloid to cause the particles in the colloid to aggregate in zones.
8. The method according to any one of claims 1 to 7, characterized in that the acting force is a non-contact induction force.
9. The method according to claim 8, wherein the non-contact induction force is magnetic force and the particles are magnetic particles; or the non-contact induction force is electrostatic force and the particles are charged particles.
10. The method according to any one of claims 1 to 9, characterized in that solidifying the colloid to form a grating with a preset period includes:

    When the force application time exceeds the preset time, the colloid is thermally cured or light cured to form a grating with a preset period, wherein the particles in the colloid are fully aggregated within the force application time.
11. The method according to any one of claims 1 to 10, characterized in that the acting force is magnetic force, the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.
12. The method according to any one of claims 1 to 11, characterized in that the colloid is polymethylmethacrylate PMMA and/or polydimethylsiloxane PDMS, and the particles are any one of the following : Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , nickel Ni.
13. A grating characterized by including:

    Solidified colloid, the solidified colloid includes a particle aggregation area and a non-particle aggregation area, the particle aggregation area and the non-particle aggregation area are formed by applying force on the colloid at intervals, the particle aggregation area and the non-particle aggregation area are Corresponds to the area where the force is applied.
14. The grating according to claim 13, wherein the number of particles in the non-particle agglomeration area is less than The number of particles in the particle aggregation area.
15. The grating according to claim 13 or 14, wherein the refractive index of the particle gathering area is greater than the refractive index of the non-particle gathering area.
16. The grating according to any one of claims 13 to 15, wherein the difference between the refractive index of the particle gathering area and the refractive index of the non-particle gathering area is greater than or equal to 0.2.
17. The grating according to claims 13 to 16, characterized in that the acting force is a non-contact induction force.
18. The grating according to claim 17, wherein the non-contact induction force is magnetic force and the particles are magnetic particles; or the non-contact induction force is electrostatic force and the particles are charged particles.
19. The grating according to any one of claims 13 to 18, characterized in that the acting force is magnetic force, the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.
20. The grating according to any one of claims 13 to 19, characterized in that the colloid is polymethylmethacrylate PMMA and/or polydimethylsiloxane PDMS, and the particles are any one of the following : Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , nickel Ni.
21. A device, characterized by comprising a grating according to any one of claims 13 to 20.
22. A device for making gratings, which is characterized by including:

    A force application module is used to apply force at intervals on the colloid containing particles, so as to cause the particles in the colloid to aggregate in zones;

    A curing module is used to solidify the colloid to form a grating with a preset period. There is a corresponding relationship between the period of the grating and the separation distance of the force.
23. The device according to claim 22, wherein the grating includes a particle aggregation area and a non-particle aggregation area, and the number of particles in the non-particle aggregation area is less than the particle number in the particle aggregation area.
24. The apparatus of claim 23, wherein the refractive index of the particle-aggregated region is greater than the refractive index of the non-particle-aggregated region.
25. The device according to claim 23 or 24, characterized in that the difference between the refractive index of the particle aggregation area and the refractive index of the non-particle aggregation area is greater than or equal to 0.2.
26. The device according to any one of claims 22 to 25, wherein the particle-containing colloid is laid on the first surface of the substrate.
27. The apparatus according to claim 26, wherein a cover plate is provided on a side of the particle-containing colloid away from the first surface.
28. The device according to any one of claims 22 to 27, characterized in that the force application module is also used for:

    Apply force at intervals on one side of the particle-containing colloid to cause the particles in the colloid to aggregate in zones; or,

    Forces are applied at intervals on both sides of the particle-containing colloid to cause the particles in the colloid to aggregate in zones.
29. The device according to any one of claims 22 to 28, wherein the force is a non-contact induction force.
30. The device according to claim 29, wherein the non-contact induction force is magnetic force and the particles are magnetic particles; or the non-contact induction force is electrostatic force and the particles are charged particles.
31. The device according to any one of claims 22 to 30, characterized in that the curing module is also used to: perform thermal curing or light curing of the colloid when the force application time exceeds a preset time. , forming a grating with a preset period, in which the particles in the colloid are fully aggregated within the force application time.
32. The device according to any one of claims 22 to 31, characterized in that the acting force is magnetic force, the magnitude of the magnetic force is 0.001T to 10T, and T is the magnetic force unit Tesla.
33. The device according to any one of claims 22 to 32, characterized in that the colloid is polymethylmethacrylate PMMA and/or polydimethylsiloxane PDMS, and the particles are any one of the following : Fe ₃ O ₄ , cobalt ferrite CoFe ₂ O ₄ , cobalt manganate MnFe ₂ O ₄ , nickel Ni.