CN115166885B

CN115166885B - Diffraction grating structure, preparation method, imaging device and head-mounted equipment

Info

Publication number: CN115166885B
Application number: CN202211098493.8A
Authority: CN
Inventors: 杨汉宁
Original assignee: Honor Device Co Ltd
Current assignee: Honor Device Co Ltd
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2023-02-17
Anticipated expiration: 2042-09-09
Also published as: CN115166885A

Abstract

The embodiment of the application provides a diffraction grating structure, a preparation method, an imaging device and head-mounted equipment. The method comprises the following steps: processing a seal with a preset pattern; printing a plurality of molecular layer stripes matched with a preset pattern on the surface of the optical waveguide through a seal, wherein the self-assembly molecules in the same molecular layer stripe are self-assembled on the surface of the optical waveguide; wherein, the molecular layer stripe is internally provided with a plurality of self-assembly molecules; providing a plurality of nanoparticles to the surface of the optical waveguide, and patterning and connecting the plurality of nanoparticles on the surface of the optical waveguide through self-assembly molecules so that the molecular layer stripes and the nanoparticles together form nanoparticle stripes. The preparation method of the diffraction grating structure is simple in process and convenient to operate, and influence of processing equipment on preparation of the diffraction grating can be reduced.

Description

Diffraction grating structure, preparation method, imaging device and head-mounted equipment

Technical Field

The present application relates to the field of optical element technology, and in particular, to a diffraction grating structure, a manufacturing method, an imaging device, and a head-mounted device.

Background

With the progress of computer hardware and software technology and optical design and manufacturing technology, VR (Virtual Reality), AR (Augmented Reality), and MR (Mix Reality) technologies are rapidly developing.

Near-eye display systems of AR need to have a larger exit pupil area to enhance the user's wearing experience. In order to increase the exit pupil area, the near-eye display system needs to set a diffraction grating to implement pupil expansion. Wherein, the diffraction grating is prepared by nano-imprinting or holographic exposure.

However, the manufacturing method of the diffraction grating is complicated in process and is easily affected by processing equipment.

Disclosure of Invention

The embodiment of the application provides a diffraction grating structure, a preparation method, an imaging device and a head-mounted device, which are simple in process and convenient to operate, and can reduce the influence of processing equipment on the preparation of the diffraction grating.

In a first aspect, an embodiment of the present application provides a method for manufacturing a diffraction grating structure. The method comprises the following steps:

processing a seal with a preset pattern; the preset pattern comprises a plurality of grooves which are arranged at intervals;

printing a plurality of molecular layer stripes matched with a preset pattern on the surface of the optical waveguide through a seal, wherein the self-assembly molecules in the same molecular layer stripe are self-assembled on the surface of the optical waveguide; wherein the molecular layer stripe is internally provided with a plurality of self-assembled molecules;

providing a plurality of nanoparticles to the surface of the optical waveguide, and patterning and connecting the plurality of nanoparticles on the surface of the optical waveguide through self-assembly molecules so that the molecular layer stripes and the nanoparticles together form nanoparticle stripes.

According to the preparation method of the diffraction grating, the self-assembly molecules are self-assembled on the surface of the optical waveguide, the nano particles are arranged in a patterning mode through the self-assembly molecules, and the nano particles are connected to the surface of the optical waveguide.

In a possible implementation manner, the method for manufacturing a diffraction grating structure provided in the examples of the present application, in which the respective assembly molecules in the same molecular layer stripe are self-assembled on the surface of the optical waveguide, includes:

the self-assembly molecules in the stripes of the same molecular layer are self-assembled on the surface of the optical waveguide, so that the respective assembly molecules are arranged in a patterning mode, and the first functional groups of the self-assembly molecules are connected with the surface of the optical waveguide. The patterned arrangement of the respective assembly molecules serves to provide a basis for the patterned arrangement of the nanoparticles.

In a possible implementation manner, a method for manufacturing a diffraction grating structure provided in an embodiment of the present application, in which a plurality of nanoparticles are provided to a surface of an optical waveguide, and the plurality of nanoparticles are arranged and connected to the surface of the optical waveguide in a patterned manner by self-assembling molecules, so that a molecular layer stripe and the nanoparticles form a nanoparticle stripe together, includes:

spraying or coating a plurality of nano particles with modified molecules on the surface to the surface of the optical waveguide;

the second functional group of the self-assembly molecule reacts with and is connected with part of the modified molecules on the surface of the nano particle, so that the molecular layer stripe and the nano particle form a nano particle stripe together; wherein the self-assembling molecules are linked to the nanoparticles.

The nanoparticles are immobilized on the optical waveguide by modifying the molecules to firmly link the nanoparticles with the self-assembling molecules.

In a possible implementation manner, in the method for manufacturing a diffraction grating structure provided in the embodiment of the present application, after the nanoparticle stripes are formed; further comprising:

and covering a protective layer on the surface of the optical waveguide with the nano-particle stripes to protect the nano-particle stripes. Thus, the nanoparticles can be prevented from falling off the optical waveguide.

In a possible implementation manner, the method for manufacturing a diffraction grating structure provided in an embodiment of the present application, which processes a stamp having a preset pattern, includes:

processing a seal with two preset patterns on the same surface; the two preset patterns are spaced from each other by a preset distance, and the number of the grooves in the two preset patterns is different.

In a possible implementation manner, the method for manufacturing a diffraction grating structure provided in an embodiment of the present application prints, on a surface of an optical waveguide, a plurality of molecular layer stripes matching a preset pattern through a stamp, and includes:

printing a plurality of first molecular layer stripes and a plurality of second molecular layer stripes which are respectively matched with two preset patterns on at least one of two opposite surfaces of the optical waveguide through a stamp; one of the first molecular layer stripes and the second molecular layer stripes is used for forming an incoupling grating, the other one of the first molecular layer stripes and the second molecular layer stripes is used for forming an outcoupling grating, the distances between adjacent nanoparticle stripes in different incoupling gratings are different, and the distances between adjacent nanoparticle stripes in different outcoupling gratings are different. Thus, in the transfer process, the patterns corresponding to the coupling-in grating and the coupling-out grating can be simultaneously prepared, so that the time is saved, the processing technology of the diffraction grating is simplified, and the efficiency of preparing the diffraction grating is improved.

In a possible implementation manner, the method for manufacturing a diffraction grating structure provided in the examples of the present application, which provides a plurality of nanoparticles to a surface of an optical waveguide, includes:

providing a plurality of nanoparticles to each of the first molecular layer stripes and each of the second molecular layer stripes on the same surface of the optical waveguide, wherein each of the first molecular layer stripes and each of the second molecular layer stripes are on the same surface of the optical waveguide.

In a possible implementation manner, a method for manufacturing a diffraction grating structure provided in an embodiment of the present application provides a plurality of nanoparticles to a surface of an optical waveguide, and includes:

providing a plurality of first nanoparticles to each of the first molecular layer stripes and each of the second molecular layer stripes on the first surface of the optical waveguide;

providing a plurality of second nanoparticles to each of the first molecular layer stripes and each of the second molecular layer stripes on a second surface of the optical waveguide opposite the first surface; wherein the first nanoparticles and the second nanoparticles are different in size.

providing a plurality of first nanoparticles to each of the first molecular layer stripes on the same surface of the optical waveguide;

providing a plurality of second nanoparticles to each of the second molecular layer stripes located on the same surface of the optical waveguide; and the first molecular layer stripes and the second molecular layer stripes are positioned on the same surface of the optical waveguide, and the first nano particles and the second nano particles have different sizes.

providing a plurality of first nanoparticles and a plurality of second nanoparticles, respectively, to each first molecular layer stripe and each second molecular layer stripe located on the first surface of the optical waveguide;

providing a plurality of second nanoparticles and a plurality of first nanoparticles, respectively, to each first molecular layer stripe and each second molecular layer stripe located on a second surface of the optical waveguide opposite the first surface; wherein the first nanoparticles and the second nanoparticles are different in size.

printing a plurality of first sublayer stripes, a plurality of second sublayer stripes, a plurality of third sublayer stripes and a plurality of fourth sublayer stripes which are respectively matched with the four preset patterns on at least one of two opposite surfaces of the optical waveguide through a stamp; the first molecular layer stripes and the second molecular layer stripes are sequentially arranged in a staggered mode, the third molecular layer stripes and the fourth molecular layer stripes are sequentially arranged in a staggered mode, each first molecular layer stripe and each second molecular layer stripe are used for forming different coupling-in gratings, each third molecular layer stripe and each fourth molecular layer stripe are used for forming different coupling-out gratings, the distance between adjacent nano particle stripes in different coupling-in gratings is different, and the distance between adjacent nano particle stripes in different coupling-out gratings is different.

providing a plurality of first nanoparticles to each of the first molecular layer stripes and each of the third molecular layer stripes on the same surface of the optical waveguide;

providing a plurality of second nanoparticles to each second sublayer stripe and each fourth sublayer stripe on the same surface of the optical waveguide; each first molecular layer stripe, each second molecular layer stripe, each third molecular layer stripe and each fourth molecular layer stripe are all positioned on the same surface of the optical waveguide, and the first nano-particles and the second nano-particles are different in size.

providing a plurality of first nanoparticles to each of the first molecular layer stripes and each of the third molecular layer stripes on the first surface of the optical waveguide, and a plurality of second nanoparticles to each of the second molecular layer stripes and each of the fourth molecular layer stripes;

providing a plurality of first nanoparticles or a plurality of second nanoparticles to each of the first molecular layer stripes and each of the third molecular layer stripes on a second surface of the optical waveguide opposite the first surface, each of the second molecular layer stripes and each of the fourth molecular layer stripes providing a plurality of third nanoparticles; wherein the first nanoparticle, the second nanoparticle and the second nanoparticle are all different in size.

In a second aspect, an embodiment of the present application provides a diffraction grating structure, which is manufactured by using the method for manufacturing a diffraction grating structure provided in the first aspect. The cost of the diffraction grating structure is low.

In a possible implementation manner, in the diffraction grating structure provided in this embodiment of the present application, a distance between two adjacent nanoparticles in the diffraction grating structure is greater than or equal to 0nm and less than or equal to 50nm. If the distance between two adjacent nanoparticles is larger than 100nm, the resonance electromagnetic fields on the particle surfaces of two adjacent nanoparticles cannot be mutually coupled to form a coupled electromagnetic wave mode.

In a possible implementation manner, the diffraction grating structure provided in the examples of the present application, the nanoparticles are in the shape of a cube, a nanorod, or a nanosphere. The diffraction effect is better by adopting the nano particles 400 with regular shapes.

In a possible implementation manner, in the diffraction grating structure provided in the embodiment of the present application, the diameter of the nanosphere is greater than or equal to 5nm and less than or equal to 100nm.

In a third aspect, an embodiment of the present application provides an imaging apparatus, including an image generation module and at least one diffraction grating structure provided in the second aspect, where the image generation module is configured to emit light to an incoupling grating of the diffraction grating structure. The smaller the number of optical waveguides in the diffraction grating structure, the thinner the thickness of the entire imaging device is accordingly.

In a fourth aspect, an embodiment of the present application provides a head-mounted device, which includes a housing and the imaging apparatus provided in the third aspect, where the imaging apparatus is disposed on the housing.

Drawings

FIG. 1 is a first diagram illustrating a structure of a diffraction grating structure according to the related art;

FIG. 2 is a second schematic structural diagram of a diffraction grating structure in the related art;

fig. 3 is a first flowchart of a method for manufacturing a diffraction grating structure according to an embodiment of the present disclosure;

FIG. 4 is a schematic structural diagram of the stamp prepared in FIG. 3;

FIG. 5 is a schematic view of the internal structure of FIG. 4;

FIG. 6 is a schematic structural diagram of a stamp filled with the self-assembled molecular solution in FIG. 5;

FIG. 7 is a schematic structural diagram of the stamp of FIG. 3 printed on the surface of the optical waveguide;

FIG. 8 is a first schematic diagram of the structure of the optical waveguide and the molecular layer stripe in FIG. 3;

FIG. 9 is a schematic structural view of the diffraction grating structure fabricated in FIG. 3;

fig. 10 is a second flowchart of a method for manufacturing a diffraction grating structure according to an embodiment of the present disclosure;

FIG. 11 is a schematic view of the internal structure of FIG. 9;

FIG. 12 is an enlarged view of a portion of FIG. 11 at A;

fig. 13 is a schematic structural diagram of a diffraction grating structure manufactured by the method for manufacturing a diffraction grating structure according to the embodiment of the present application;

fig. 14 is a first schematic structural diagram of a processed stamp in a manufacturing method of a diffraction grating structure provided in an embodiment of the present application;

fig. 15 is a second schematic structural diagram of a processed stamp in the method for manufacturing a diffraction grating structure according to the embodiment of the present application;

FIG. 16 is a second schematic diagram of the structure of the optical waveguide and the molecular layer stripe in FIG. 3;

FIG. 17 is a third schematic diagram of the structure of the optical waveguide and the molecular layer stripes of FIG. 3;

FIG. 18 is a fourth schematic structural view of the optical waveguide and molecular layer stripes of FIG. 3;

FIG. 19 is a fifth schematic structural view of the optical waveguide and molecular layer stripes of FIG. 3;

fig. 20 is a sixth schematic structural view of the optical waveguide and molecular layer stripes of fig. 3;

fig. 21 is a seventh schematic structural view of the optical waveguide and the molecular layer stripe of fig. 3;

fig. 22 is a schematic view eight of the structure of the optical waveguide and the molecular layer stripe in fig. 3;

FIG. 23 is a schematic structural view of a portion of the diffraction grating structure fabricated in FIG. 22;

fig. 24 is a ninth schematic structural view of the optical waveguide and the molecular layer stripe of fig. 3;

fig. 25 is a schematic ten view of the structure of the optical waveguide and the molecular layer stripe of fig. 3;

FIG. 26 is an eleventh schematic view of the structure of the optical waveguide and the molecular layer stripe of FIG. 3;

fig. 27 is a first schematic structural diagram of an imaging apparatus according to an embodiment of the present disclosure;

fig. 28 is a schematic structural diagram of an imaging apparatus according to an embodiment of the present application;

fig. 29 is a schematic structural diagram three of an imaging apparatus according to an embodiment of the present application;

fig. 30 is a schematic structural diagram of an imaging apparatus according to an embodiment of the present application;

fig. 31 is a schematic structural diagram of a head-mounted device according to an embodiment of the present application.

Description of the reference numerals:

10-a display; 20-one-dimensional incoupling grating; 30-one-dimensional turning grating; a 40-one-dimensional outcoupling grating; 50-eye; 51-the retina; 60-a window; 70-two-dimensional outcoupling grating;

100-a seal; 110-a groove; 120-a first preset pattern; 130-a second preset pattern;

200-an optical waveguide; 210-a first surface; 220-a second surface;

300-self-assembling molecular solution; 310-a self-assembling molecule; 311-a first functional group; 312-a second functional group; 320-molecular layer stripes; 321-first molecular layer stripes; 322-second molecular layer stripes; 323-third sublayer stripes; 324-fourth sublayer stripes;

400-nanoparticles; 410-a modifying molecule;

500-nanoparticle stripes; 510 a-red incoupling grating; 510 b-green coupler grating; 510 c-blue incoupling grating; 520 a-red out-coupling grating; 520 b-green out-coupling grating; 520 c-blue outcoupling grating;

600-a protective layer;

700-an image generation module;

800-an imaging device;

900-shell.

Detailed Description

In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations for the purpose of clearly describing technical solutions of the embodiments of the present application. Any embodiment or design described herein as "exemplary" or "such as" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present relevant concepts in a concrete fashion.

In the embodiments of the present application, "a plurality" means two or more.

The terminology used in the description of the embodiments section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application.

Total reflection refers to a phenomenon that occurs when light is emitted from a high refractive index medium to a low refractive index medium and the incident angle is equal to or greater than a critical angle. That is, when the total reflection condition is satisfied, light is continuously propagated forward by reflection in the waveguide sheet and is not transmitted out, so that the propagation direction of light can be changed.

A waveguide sheet, which may also be referred to as an optical waveguide, is a dielectric device that guides light waves to propagate therein. Planar dielectric optical waveguides are the simplest optical waveguides, using a refractive index of n ₂ Silicon dioxide as substrate, on which a layer with refractive index n can be deposited by microelectronics processes ₁ A dielectric film of (2), in addition to a refractive index of n ₃ Is made of the cover layer. Usually given as n ₁ >n ₂ >n ₃ So as to confine the light wave to propagate in the dielectric film.

Self-assembly, refers to a technique in which basic building blocks (molecules, nanomaterials, substances on the micrometer or larger scale) spontaneously form ordered structures. During the self-assembly process, the basic building blocks spontaneously organize or aggregate into a stable structure with a certain regular geometric appearance under the interaction based on non-covalent bonds.

Surface plasmons are electromagnetic modes formed by the interaction of one free electron and a photon at the interface region of a metal and a medium. When light waves (electromagnetic waves) enter a metal and dielectric medium interface, free electrons on the surface of the metal are subjected to collective oscillation, the electromagnetic waves and the free electrons on the surface of the metal are coupled to form a near-field electromagnetic wave which propagates along the surface of the metal, if the oscillation frequency of the electrons is consistent with the frequency of the incident light, resonance is generated, and the energy of the electromagnetic field in the resonance state is effectively converted into collective oscillation energy of the free electrons on the surface of the metal, so that a special electromagnetic mode is formed: the electromagnetic field is confined to a small range of the metal surface and enhanced, and this phenomenon is called a surface plasmon phenomenon.

The near-eye display system of the AR may include a display device and an optical imaging element. The working principle of the near-eye display system is as follows: pixels on the display device form a far and near virtual image through an optical imaging element and are projected into human eyes. The optical imaging element may include a diffraction grating, which is an optical element that separates light of different wavelengths using an optical diffraction phenomenon on a periodic or quasi-periodic grating structure. The diffraction grating may include a waveguide sheet and a grating structure.

The near-eye display system may be augmented reality glasses or augmented reality head-mounted display devices, or the like. For ease of description, augmented reality glasses are described below.

The display device is used to output images, however, if the display device is directly placed on the lenses of the augmented reality glasses, the user's sight is blocked and the display device is not beautiful. Based on the total reflection principle, the waveguide sheet can transfer the image projected by the display device in an equal ratio, and then the display device can be placed on the top or the side of the augmented reality glasses. Therefore, the sight of the user is not obstructed. Moreover, because the light transmittance of the waveguide sheet is high and very light and thin, the augmented reality glasses can be closer to the common glasses on the basis of realizing the virtual-real fused display effect.

It should be noted that the waveguide sheet is only responsible for transferring and transmitting the image to the human eye, and has no function of enlarging or reducing the image. Therefore, the exit pupil of the waveguide piece is expanded through the two-dimensional pupil expansion, the eye movement range is increased in two directions on the premise of ensuring small size and large visual field angle, and strong immersion feeling and good visual experience are further obtained.

In order to increase the exit pupil area, the near-eye display system needs to set a grating to realize the pupil expansion. In which the grating must go through the coupling-in and coupling-out process if the light guide from the display device (also optical engine) is to be projected into the human eye. That is, light emitted from the display device enters the waveguide of the incoupling grating through the incoupling grating, and is totally reflected and propagated therein, and finally, the light is transmitted to human eyes through the incoupling grating.

Fig. 1 is a first structural diagram of a diffraction grating structure in the related art. As shown in fig. 1, in the related art, the pupil can be expanded two-dimensionally by three gratings, namely, a one-dimensional in-coupling grating 20, a one-dimensional turning grating 30 and a one-dimensional out-coupling grating 40.

Light emitted from the display 10 is coupled into the waveguide sheet through the one-dimensional incoupling grating 20, and then is incident on the one-dimensional turning grating 30 through total reflection. At this point, a portion of the light will be diverted to the one-dimensional outcoupling grating 40, and the remaining light will continue to propagate forward by reflection and then be incident again on the one-dimensional diverting grating 30. A portion of the light is deflected to the one-dimensional outcoupling grating 40, and repeating this process achieves a one-dimensional pupil expansion. Finally, a part of the light transmitted to the one-dimensional coupling-out grating 40 will be transmitted to the retina 51 of the user's eye 50 by diffraction, and the rest of the light will continue to propagate forward by reflection and then be incident on the one-dimensional coupling-out grating 40 again, and a part of the light will be transmitted to the retina 51 of the eye 50 again, and the process is repeated to realize one-dimensional pupil expansion in the other direction. The two times of one-dimensional pupil expansion are combined to form a two-dimensional pupil expansion. Thereby making the viewing window 60 larger than the eye 50, which allows for some degree of movement and rotation of the user's eye 50, and also accommodates different arrangements of the near-eye display relative to the eyes of different users, as well as different interpupillary distances of different users.

Fig. 2 is a second structural diagram of a diffraction grating structure in the related art. As shown in fig. 2, in the related art, a one-dimensional incoupling grating 20 and a two-dimensional outcoupling grating 70 are used. Similarly, light emitted from the display 10 is coupled into the waveguide sheet through the one-dimensional coupling-in grating 20, and then is incident on the two-dimensional coupling-out grating 70 through total reflection, at this time, a part of light is transmitted into the retina 51 of the eye 50 of the user through diffraction, the rest light is divided into horizontal and vertical directions and is reflected to continue to propagate forwards, and then is incident on the two-dimensional coupling-out grating 70 again, at this time, a part of light is transmitted into the human eye, and the process is repeated, so that the two-dimensional pupil expansion is realized, and the window 60 is larger than the eye 50.

In the related art, the diffraction grating is manufactured by means of nanoimprint or holographic exposure. The preparation of the diffraction grating by the nanoimprint lithography method can include the following three steps.

In the first step of processing the master template, an ion beam etching process is utilized to process the grating master template on a silicon or other substrates. Wherein, the female template is a hard template.

And secondly, pattern transfer, namely coating ultraviolet curing resin on the surface of the material to be processed, pressing the master template on the surface of the material to be processed, and transferring the pattern to the ultraviolet curing resin in a pressurizing mode. The ultraviolet curing resin can not be completely removed, so that the template is prevented from being damaged due to direct contact between the mother template and the material. The pressure applied to the female template can affect the service life of the female template and cause great loss to the female template.

And thirdly, processing the material to be processed. And (4) after the mother template is removed, ultraviolet light is used for curing the ultraviolet curing resin, and a resin structure with fixed periodic patterns is formed.

The diffraction grating is prepared by holographic exposure, and a coating layer of photoresist or other photosensitive material with a given thickness is coated on an optically stable flat glass blank. The photosensitive material is sensitized to form index-modulated interference fringes within the coating by generating two coherent beams from a laser that produce a series of uniform interference fringes across the coating.

However, the above-mentioned process for preparing the diffraction grating by nanoimprint lithography or holographic exposure is complicated and is easily affected by processing equipment.

Based on this, the embodiment of the application provides a method for preparing a diffraction grating structure, which is simple in process and convenient to operate, and can reduce the influence of processing equipment on the preparation of the diffraction grating.

Fig. 3 is a first flowchart of a manufacturing method of a diffraction grating structure according to an embodiment of the present disclosure. As shown in fig. 3, a method for manufacturing a diffraction grating structure provided in the embodiment of the present application includes:

s101, processing a stamp 100 with a preset pattern; wherein the predetermined pattern includes a plurality of grooves 110 arranged at intervals.

FIG. 4 is a schematic structural diagram of the stamp prepared in FIG. 3; fig. 5 is a schematic view of the internal structure of fig. 4. As shown in fig. 4 and fig. 5, in the present embodiment, the stamp 100 may also be referred to as a mold, the stamp 100 is an elastic substrate, and the material of the stamp 100 may be Polydimethylsiloxane (PDMS) or polymethyl methacrylate (PMMA). Exemplarily, the material of seal 100 is PDMS, and PDMS's material surface energy is lower for seal 100 has better from the type effect. PDMS has higher dielectric property and better flexibility, so that the stamp 100 has better electrostatic adsorption and good bonding effect. Compared with a hard template in the related art, the stamp 100 is soft and has good compression resistance.

In particular implementations, stamp 100 having recesses 110 may be prepared by a hot-pressing process. The hot-pressing method for preparing the seal 100 has the advantages of simple process and higher efficiency.

The stamp 100 has a plurality of grooves 110, the grooves 110 may be uniformly spaced, and the grooves 110 form a predetermined pattern. In this embodiment, the shape and size of the groove 110 are not limited, and the predetermined pattern may be matched with the pattern of the grating on the grating structure to be prepared.

S102, printing a plurality of molecular layer stripes 320 matched with a preset pattern on the surface of the optical waveguide 200 through the stamp 100, and self-assembling respective assembling molecules 310 in the same molecular layer stripe 320 on the surface of the optical waveguide 200; wherein the molecular layer stripe 320 has a plurality of self-assembled molecules 310 therein.

Fig. 6 is a schematic structural view of a stamp filled with the self-assembly molecular solution in fig. 5. As shown in fig. 6, a self-assembling molecular solution 300 is filled on the side of the stamp 100 having the groove 110, so that the self-assembling molecular solution 300 is completely filled in the groove 110, and then the self-assembling molecular solution 300 on the side of the stamp 100 having the groove 110 is scraped.

Wherein, water and self-assembling molecules 310 (e.g., water-soluble molecules) may be included in the self-assembling molecule solution 300; alternatively, other organic solvents and self-assembling molecules 310 may be included in the self-assembling molecule solution 300.

FIG. 7 is a schematic structural diagram of the stamp printed on the surface of the optical waveguide in FIG. 3; fig. 8 is a first schematic structural diagram of the optical waveguide and the molecular layer stripe in fig. 3.

As shown in fig. 7 and 8, the groove 110 faces the optical waveguide 200, the stamp 100 having the self-assembly molecular solution 300 in the groove 110 is covered on the optical waveguide 200, so that the self-assembly molecular solution 300 in the groove 110 is transferred onto the surface of the optical waveguide 200, the self-assembly molecular solution 300 forms a plurality of molecular layer stripes 320 on the surface of the optical waveguide 200, and then the stamp 100 is peeled off the optical waveguide 200. Wherein each molecular layer stripe 320 has a plurality of self-assembled molecules 310. Compared with the related art that patterns on the master template are transferred to ultraviolet curing resin in a pressurizing mode, the stamp 100 can be transferred by contacting with the optical waveguide 200, the stamp 100 is subjected to smaller pressure, and the service life of the stamp 100 is longer.

The molecular layer stripes 320 may have a plurality of molecular layer stripes 320, each of the molecular layer stripes 320 is a protruding layer or a self-assembled molecular film layer formed on the surface of the optical waveguide 200, the molecular layer stripes 320 correspond to the grooves 110, and a space is formed between two adjacent molecular layer stripes 320, so that self-assembly occurs in the same molecular layer stripe 320.

The self-assembly molecules 310 in the stripes 320 of the same molecular layer are associated and gathered together spontaneously and simultaneously to form a compact and ordered whole, and the self-assembly molecules 310 are connected to the surface of the optical waveguide 200, that is, the self-assembly molecules 310 are arranged on the surface of the optical waveguide 200 in a patterned manner. This process may be referred to as self-assembled processing molecular layer stripes 320. It can be seen that the self-assembled fabricated molecular layer stripe 320 of the present embodiment is simple and easy to implement, and does not need any other device for assistance.

S103, providing a plurality of nanoparticles 400 to the surface of the optical waveguide 200, and arranging and connecting the plurality of nanoparticles 400 on the surface of the optical waveguide 200 in a patterning manner by the self-assembly molecules 310, so that the molecular layer stripes 320 and the nanoparticles 400 form the nanoparticle stripes 500 together. The nanoparticle stripes 500 may also be referred to as gratings, among others.

In particular implementations, the nanoparticles 400 may be in the shape of a cube, a nanopillar (a regular prism such as a triangular prism), or a nanosphere.

Fig. 9 is a schematic structural view of the diffraction grating structure fabricated in fig. 3. For ease of illustration, the nanoparticles 400 are illustrated in FIG. 9 as nanospheres. In the compact and ordered bulk, at least one self-assembly molecule 310 is connected to the nanoparticle 400, and the nanoparticle 400 is connected to the surface of the optical waveguide 200 through the self-assembly molecule 310. Thus, the nanoparticles 400 are arranged in the same manner as the self-assembling molecules 310. Thereby, a patterned arrangement of nanoparticles 400 is achieved.

Illustratively, the nanoparticles 400 are arranged in an array, wherein the nanoparticles 400 may be in the form of a staggered array in fig. 9, and the nanoparticles 400 may also be in the form of a rectangular array. It is understood that the nanoparticles 400 may be arranged in other ways, and the embodiment is not limited thereto.

After the nanoparticles 400 are arranged in a patterned manner, when incident light is incident on the nanoparticles 400, free electrons on the surfaces of the nanoparticles 400 oscillate, the incident light is coupled with the free electrons on the surfaces of the nanoparticles 400 to form a near-field electromagnetic wave propagating along the surfaces of the nanoparticles 400, the oscillation frequency of the free electrons on the surfaces of the nanoparticles 400 is consistent with the frequency of the incident light to generate resonance, and the energy of the electromagnetic field is effectively converted into collective vibration energy of the free electrons on the surfaces of the nanoparticles 400 in a resonance state. The resonance electromagnetic fields on the surfaces of the adjacent nanoparticles 400 are coupled with each other to form a coupled electromagnetic wave mode, so that each nanoparticle 400 in the same molecular layer stripe 320 is equivalent to a metal stripe, and two adjacent molecular layer stripes 320 interact to form a diffraction grating structure.

The display provides an input light beam comprising red (R), green (G) and blue (B) colors, each color having a different wavelength, wherein the red light has a wavelength range of 622nm to 760nm, the green light has a wavelength range of 492 nm to 577nm, and the blue light has a wavelength range of 435nm to 450nm. Only light at the same wavelength band (i.e., the same color) is diffracted by the diffraction grating, and light of the remaining wavelength bands (i.e., the remaining colors) is directly transmitted through the diffraction grating. In a specific implementation, the diffraction gratings corresponding to red, green, and blue colors, respectively, may be formed by using nanoparticles 400 having the same shape and different sizes in the self-assembly molecule solution 300, or by using nanoparticles 400 having different shapes and different sizes.

It can be understood that the coupling-in grating and the coupling-out grating corresponding to the input light beams of the respective colors are formed in the same manner, in other words, the diffraction grating prepared in the above manner may be the coupling-in grating, the coupling-out grating, or both the coupling-in grating and the coupling-out grating prepared in the above manner.

In the method for manufacturing a diffraction grating provided in the embodiment of the present application, a stamp 100 having a groove 110 is used to transfer on the surface of an optical waveguide 200 to form a plurality of molecular layer stripes 320, respective assembly molecules 310 in the same molecular layer stripe 320 are self-assembled on the surface of the optical waveguide 200, so that the self-assembly molecules 310 are arranged in a patterned manner, the self-assembly molecules 310 connect nanoparticles 400 on the surface of the optical waveguide 200, so that the nanoparticles 400 are arranged in a patterned manner, the nanoparticles 400 interact with each other through a surface plasmon effect, so that each nanoparticle 400 in the same molecular layer stripe 320 is equivalent to a metal stripe, and two adjacent molecular layer stripes 320 interact with each other to form a diffraction grating structure.

In the above method for manufacturing a diffraction grating, the respective assembly molecules 310 are self-assembled on the surface of the optical waveguide 200, the nanoparticles 400 are arranged in a patterned manner by the self-assembly molecules 310, and the nanoparticles 400 are connected to the surface of the optical waveguide 200 without depending on processing equipment, and the process is simple and easy to implement. Compared with the method for preparing the diffraction grating by means of nano-imprinting or holographic exposure in the related art, the method for preparing the diffraction grating by means of the nano-imprinting or holographic exposure avoids operations such as pressurization, ultraviolet irradiation or laser adjustment (namely, avoids the use of processing equipment such as pressurization, ultraviolet irradiation or laser adjustment), is simple in process and convenient to operate, can reduce the influence of the processing equipment on the preparation of the diffraction grating, reduces the influence of processing errors of the processing equipment and the like on the yield of the preparation of the diffraction grating, and therefore can save the processing cost of the diffraction grating.

Next, the above step S103 will be described with reference to specific embodiments.

Fig. 10 is a second flowchart of a method for manufacturing a diffraction grating structure according to an embodiment of the present disclosure; FIG. 11 is a schematic view of the internal structure of FIG. 9; fig. 12 is a partial enlarged view of a portion a in fig. 11. As shown in fig. 9 to 12, in a specific implementation, the method for manufacturing a diffraction grating structure provided in the embodiment of the present application may include:

s201, the respective assembly molecules 310 in the same molecular layer stripe 320 self-assemble on the surface of the optical waveguide 200, so that the respective assembly molecules 310 are arranged in a patterned manner, and the first functional group 311 of the self-assembly molecules 310 is connected with the surface of the optical waveguide 200.

Specifically, a reaction occurs between the first functional group 311 of the self-assembled molecule 310 and the molecules of the surface of the optical waveguide 200, thereby fixing one end of the self-assembled molecule 310 on the surface of the optical waveguide 200.

And S202, spraying or coating a plurality of nanoparticles 400 with modification molecules 410 on the surface to the surface of the optical waveguide 200.

Specifically, the nanoparticles 400 are provided on the surface of the optical waveguide 200 by spraying or coating, which is convenient for operation.

S203, the second functional group 312 of the self-assembly molecule 310 and a part of the modified molecules 410 on the surface of the nanoparticle 400 are in reactive linkage, so that the molecular layer stripe 320 and the nanoparticle 400 together form a nanoparticle stripe 500; wherein the self-assembling molecules 310 are attached to the nanoparticles 400.

In the present application, self-assembling molecules 310 are used to attach to nanoparticles 400, and the patterned arrangement of the respective assembling molecules 310 is used to provide a basis for the patterned arrangement of nanoparticles 400.

The surface of the nanoparticle 400 is relatively smooth, which is not conducive to the attachment of the nanoparticle 400 to the self-assembling molecule 310. In particular, the surface of the nanoparticle 400 needs to be molecularly processed, so that the modified molecules 410 are formed on the surface of the nanoparticle 400. A reaction occurs between the modified molecule 410 and the second functional group 312 of the self-assembling molecule 310, thereby attaching the nanoparticle 400 to the self-assembling molecule 310.

After the above-described diffraction grating structure is fabricated, there is a risk that the nanoparticle stripes 500 may be dislodged from the surface of the optical waveguide 200 during placement, transportation, or installation.

Fig. 13 is a schematic structural diagram of a diffraction grating structure manufactured by the method for manufacturing a diffraction grating structure according to the embodiment of the present application. Referring to fig. 13, in some embodiments, after the nanoparticle stripes 500 are formed; further comprising:

the surface of optical waveguide 200 having nanoparticle stripe 500 is covered with a protective layer 600 to protect nanoparticle stripe 500.

Specifically, protective layer 600 covers the surface of optical waveguide 200 having nanoparticle stripes 500, thereby securing nanoparticle stripes 500 within protective layer 600. This increases the reliability of nanoparticle stripe 500, i.e., maintains the stability of the connection between nanoparticle stripe 500 and optical waveguide 200. In this way, the nanoparticle stripes 500 are prevented from falling off the surface of the optical waveguide 200 during placement, transportation, or installation.

In particular implementations, no limitation is placed on the thickness of protective layer 600, so long as nanoparticle stripes 500 are located within protective layer 600 and do not affect the performance of the diffraction grating structure.

The protection layer 600 may be an organic layer, and the material of the organic layer includes acrylate, polyurethane, and the like.

The diffraction grating structure includes an optical waveguide 200, an in-coupling grating and an out-coupling grating, both of which are located on the optical waveguide 200. In the above-described diffraction grating structure preparation, at least one of the in-coupling grating and the out-coupling grating is formed in the same manner as the nanoparticle stripe 500.

The following describes how the in-grating and the out-grating are formed in conjunction with the embodiments and the drawings.

Fig. 14 is a first schematic structural diagram of a processed stamp in the method for manufacturing a diffraction grating structure according to the embodiment of the present application. Fig. 15 is a second schematic structural diagram of a processed stamp in the method for manufacturing a diffraction grating structure according to the embodiment of the present application. As shown in fig. 14 and 15, in some embodiments, processing a stamp 100 having a predetermined pattern includes:

processing a stamp 100 having two preset patterns on the same surface; wherein, a preset distance is provided between the two preset patterns, and the number of the grooves 110 in the two preset patterns is different.

The two predetermined patterns may include a first predetermined pattern 120 and a second predetermined pattern 130, wherein the first predetermined pattern 120 and the second predetermined pattern 130 each include a plurality of grooves 110 arranged at intervals, and the intervals between the grooves 110 in the first predetermined pattern 120 and the intervals between the grooves 110 in the second predetermined pattern 130 may be the same or different.

One of the first predetermined pattern 120 and the second predetermined pattern 130 matches the incoupling grating, and the other matches the outcoupling grating. In the present embodiment, the preset interval between the first preset pattern 120 and the second preset pattern 130 is the same as the interval between the incoupling grating and the outcoupling grating.

Since the light is transmitted to the human eye through the coupling-out grating, the size of the corresponding grating along the direction B in fig. 14 or 15 is larger by the larger number of the grooves 110 in the first predetermined pattern 120 or the second predetermined pattern 130, and thus, the area of the window can be increased. Accordingly, the number of the grooves 110 in the first predetermined pattern 120 or the second predetermined pattern 130 corresponding to the incoupling grating may be set to be greater than the number of the grooves 110 in the first predetermined pattern 120 or the second predetermined pattern 130 corresponding to the incoupling grating.

In a specific implementation, the shape and the pitch of the grooves 110 in both the first and second

predetermined patterns

120 and 130 are not limited. As shown in fig. 14, the shape and the pitch of the grooves 110 in both the first and second

preset patterns

120 and 130 may be the same. As shown in fig. 15, the shapes and the pitches of the grooves 110 in both the first and second

preset patterns

120 and 130 may also be different. As long as the stamp 100 can smoothly perform transfer.

In this embodiment, by providing the first preset pattern 120 and the second preset pattern 130 on the same surface of the stamp 100, patterns corresponding to the coupling-in grating and the coupling-out grating can be simultaneously prepared in the transfer process, thereby saving time, simplifying the processing process of the diffraction grating, and improving the efficiency of preparing the diffraction grating.

FIG. 16 is a second schematic diagram of the structure of the optical waveguide and the molecular layer stripe in FIG. 3; FIG. 17 is a third schematic diagram of the structure of the optical waveguide and the molecular layer stripes of FIG. 3; fig. 18 is a fourth schematic structural view of the optical waveguide and the molecular layer stripe in fig. 3. As shown in fig. 8 and 14 to 18, printing a plurality of molecular layer stripes 320 matched with a preset pattern on the surface of the optical waveguide 200 by the stamp 100 includes:

printing a plurality of first molecular layer stripes 321 and a plurality of second molecular layer stripes 322 respectively matched with the two preset patterns on at least one of two opposite surfaces of the optical waveguide 200 through the stamp 100; one of the first molecular-layer stripes 321 and the second molecular-layer stripes 322 is used to form an in-grating, and the other is used to form an out-grating. The distances between adjacent nanoparticle stripes 500 in different outcoupling gratings are different, and the distances between adjacent nanoparticle stripes 500 in different outcoupling gratings are different. In other words, the distance between adjacent nanoparticle stripes 500 in an incoupling photogate corresponding to one of red, blue or green is different from the distance between adjacent nanoparticle stripes 500 in any other corresponding incoupling photogate (e.g., the distance between adjacent nanoparticle stripes 500 in an incoupling photogate corresponding to red is different from the distance between adjacent nanoparticle stripes 500 in an incoupling photogate corresponding to blue); the distance between adjacent nanoparticle stripes 500 in an outcoupling grid corresponding to one of the colors red, blue or green is different from the distance between adjacent nanoparticle stripes 500 in any of the remaining outcoupling grids (e.g., the distance between adjacent nanoparticle stripes 500 in an outcoupling grid corresponding to the color red is different from the distance between adjacent nanoparticle stripes 500 in an outcoupling grid corresponding to the color blue).

The self-assembled molecular solution 300 is transferred to the same surface of the optical waveguide 200 by the stamp 100 having the first predetermined pattern 120 and the second predetermined pattern 130, so that a plurality of first molecular layer stripes 321 and a plurality of second molecular layer stripes 322 are formed on the same surface of the optical waveguide 200. Wherein each first molecular layer stripe 321 matches with the groove 110 in the first predetermined pattern 120, and each second molecular layer stripe 322 matches with the groove 110 in the second predetermined pattern 130.

It should be noted that, in the present application, the first preset pattern 120 and the second preset pattern 130 are only when the number of the preset patterns is two, and for the distinction between the two preset patterns, the structure and the forming manner of the first preset pattern 120 and the second preset pattern 130 are the same as the preset patterns. Similarly, as shown in fig. 8, 16 and 17, the first molecular layer stripe 321 and the second molecular layer stripe 322 are only configured and formed in the same manner as the molecular layer stripes 320 for distinguishing the two molecular layer stripes 320 when the number of the molecular layer stripes 320 is two. The following similar expressions have the same meanings.

It will be appreciated that the corresponding in-and out-coupling gratings of red, green or blue colors are formed by the shape and size of the nanoparticles 400. The arrangement of the nanoparticles 400 in the in-grating and the out-grating corresponding to the same color may be the same. The arrangement of the nanoparticles 400 in the in-grating and the out-grating corresponding to different colors may be the same or different.

In one possible implementation, a plurality of nanoparticles 400 are provided to each of first-molecular-layer stripes 321 and each of second-molecular-layer stripes 322 located on the same surface of optical waveguide 200, wherein each of first-molecular-layer stripes 321 and each of second-molecular-layer stripes 322 are located on the same surface of optical waveguide 200.

That is, the first molecular-layer stripe 321 and the second molecular-layer stripe 322 are both located on the same surface of the optical waveguide 200, and the first molecular-layer stripe 321 and the second molecular-layer stripe 322 correspond to the nanoparticles 400 having the same shape and size. As shown in fig. 12, 16 and 17, the diffraction grating of the nanoparticle 400 having the same shape and size diffracts only light at the same wavelength band (i.e., the same color), and light of the remaining wavelength bands (i.e., the remaining colors) directly transmits through the diffraction grating. Thus, it is convenient to process the same optical waveguide 200 with an incoupling grating and an outcoupling grating corresponding to red, green or blue. Wherein fig. 16 shows first molecular layer stripe 321 and second molecular layer stripe 322 at first surface 210 of optical waveguide 200. Fig. 17 shows first molecular layer stripes 321 and second molecular layer stripes 322 on second surface 220 of optical waveguide 200 opposite first surface 210.

In another possible implementation, a plurality of first nanoparticles are provided to each of first molecular layer stripes 321 and each of second molecular layer stripes 322 disposed on first surface 210 of optical waveguide 200.

Providing a plurality of second nanoparticles to each of first-molecular-layer stripe 321 and each of second-molecular-layer stripes 322 on second surface 220 of optical waveguide 200 opposite first surface 210; wherein the first nanoparticles and the second nanoparticles are different in size. Wherein dimensions are not to be understood as: the shapes are the same and the sizes are different; alternatively, the shape is different. Illustratively, the first and second nanoparticles may be one of a quadrangular prism and the other of a spherical shape. Alternatively, the first and second nanoparticles may be both spherical and have different diameters.

That is, the two opposite surfaces of the optical waveguide 200 have the first molecular layer stripe 321 and the second molecular layer stripe 322, and the first molecular layer stripe 321 and the second molecular layer stripe 322 on the same surface correspond to the first nanoparticle or the second nanoparticle with the same shape and size, and the first nanoparticle and the second nanoparticle are different in size. As shown in fig. 12 and 18, each of the first surface 210 and the second surface 220 has a first molecule layer stripe 321 and a second molecule layer stripe 322, where the first molecule layer stripe 321 of the first surface 210 and the first molecule layer stripe 321 of the second surface 220 are opposite to each other in a C direction in fig. 18, and the second molecule layer stripe 322 of the first surface 210 and the second molecule layer stripe 322 of the second surface 220 are opposite to each other or staggered from each other in the C direction in fig. 18. Thus, two diffraction grating structures shown in fig. 18 are required in the AR glasses, reducing the thickness of the AR glasses.

It should be noted that, in the present application, the nanoparticles 400 are disposed on the first molecular layer stripe 321 and the second molecular layer stripe 322, and the first molecular layer stripe 321 and the second molecular layer stripe 322 pass through different hatching lines to distinguish the nanoparticles 400 with the same shape or different shapes and sizes. The nanoparticles 400 have the same shape and size, and the hatching lines of the first molecular layer stripe 321 and the second molecular layer stripe 322 are the same; the nanoparticles 400 are different in size and the hatching of the first molecular layer stripe 321 and the second molecular layer stripe 322 is different.

The nanoparticles 400 on the first surface 210 may all be the same shape and size; the nanoparticles 400 on the second surface 220 may all be the same shape and size, with the nanoparticles 400 on the first surface 210 being different in size from the nanoparticles 400 on the second surface 220. Thereby, an in-grating and an out-grating corresponding to at least two of the red, green and blue colors are formed on the same optical waveguide 200.

FIG. 19 is a fifth schematic structural view of the optical waveguide and molecular layer stripes of FIG. 3; fig. 20 is a sixth schematic structural view of the optical waveguide and the molecular layer stripe of fig. 3. As shown in fig. 12, 19 and 20, in a third possible implementation, the first molecular-layer stripe 321 and the second molecular-layer stripe 322 are both located on the same surface of the optical waveguide 200, and the first molecular-layer stripe 321 and the second molecular-layer stripe 322 correspond to nanoparticles 400 with different shapes and sizes.

Specifically, the respective assembly molecules 310 within the same first molecular layer stripe 321 self-assemble on the surface of the optical waveguide 200 to pattern and connect the plurality of first nanoparticles on the surface of the optical waveguide 200. The respective assembly molecules 310 within the same second molecular layer stripe 322 self-assemble on the surface of the optical waveguide 200 to pattern and attach a plurality of second nanoparticles to the surface of the optical waveguide 200, wherein the first nanoparticles and the second nanoparticles are different in size. Thus, the same optical waveguide 200 may have an in-grating corresponding to one of red, green and blue, and an out-grating corresponding to the other.

Wherein fig. 19 shows first molecular layer stripe 321 and second molecular layer stripe 322 at first surface 210 of optical waveguide 200. Fig. 20 shows first molecular layer stripe 321 and second molecular layer stripe 322 at second surface 220 of optical waveguide 200 opposite first surface 210. The first molecular layer stripe 321 is used for disposing a first nanoparticle, and the second molecular layer stripe 322 is used for disposing a second nanoparticle.

Fig. 21 is a seventh schematic structural view of the optical waveguide and the molecular layer stripe in fig. 3. As shown in fig. 12, 13, and 21, in a fourth possible implementation, a plurality of first nanoparticles and a plurality of second nanoparticles are provided to each of the first-molecular-layer stripes 321 and each of the second-molecular-layer stripes 322 located on the first surface 210 of the optical waveguide 200, respectively; providing a plurality of second nanoparticles and a plurality of first nanoparticles to each of first-molecular-layer stripes 321 and each of second-molecular-layer stripes 322 on a second surface 220 of optical waveguide 200 opposite first surface 210, respectively; wherein the first nanoparticles and the second nanoparticles are different in size. I.e. corresponding incoupling and outcoupling gratings of the same color are located at the first surface 210 and the second surface 220, respectively.

In the above four possible implementations, one in-grating and one out-grating are formed for the same surface of the optical waveguide 200.

In some implementations, the same surface of the optical waveguide 200 may form two in-coupling gratings and two out-coupling gratings. Wherein one incoupling grating and one outcoupling grating correspond to one of red, green and blue, and the other incoupling grating and the other outcoupling grating correspond to the other of red, green and blue. The distances between adjacent nanoparticle stripes 500 in different outcoupling gratings are different, and the distances between adjacent nanoparticle stripes 500 in different outcoupling gratings are different. In other words, the distances between adjacent nanoparticle stripes 500 in the coupled-in photogate respectively corresponding to red, blue and green are all different, and the distances between adjacent nanoparticle stripes 500 in the coupled-out photogate respectively corresponding to red, blue and green are all different.

It is understood that, as shown in fig. 5 to 9, in the present application, the groove 110 is filled with the self-assembly molecule solution 300, the molecular layer stripe 320 is formed after the self-assembly molecule solution 300 is transferred onto the surface of the optical waveguide 200, and the nanoparticle stripe 500 is formed after the nanoparticle 400 is sprayed or coated on the molecular layer stripe 320. That is, the distance between adjacent nanoparticle stripes 500 corresponds to the distance between adjacent molecular layer stripes 320, and the distance between adjacent molecular layer stripes 320 corresponds to the distance between adjacent grooves 110, and if the distance between adjacent nanoparticle stripes 500 is to be limited, the distance between adjacent grooves 110 can be controlled.

Fig. 22 is a schematic view eight of the structures of the optical waveguide and the molecular layer stripe in fig. 3; FIG. 23 is a schematic diagram of a portion of the structure of the diffraction grating structure fabricated in FIG. 22; fig. 24 is a schematic illustration nine of the structures of the optical waveguide and the molecular layer stripes of fig. 3; fig. 25 is a ten-fold schematic structural view of the optical waveguide and molecular layer stripes of fig. 3; fig. 26 is an eleventh schematic view of the structure of the optical waveguide and the molecular layer stripe in fig. 3. As shown in fig. 12, 22-25, in some implementations, a plurality of first-sublayer stripes 321, a plurality of second-sublayer stripes 322, a plurality of third-sublayer stripes 323, and a plurality of fourth-sublayer stripes 324 matching the four preset patterns, respectively, are printed by stamp 100 on at least one of the two opposing surfaces of optical waveguide 200; the first sub-layer stripes 321 and the second sub-layer stripes 322 are sequentially arranged in a staggered manner, the third sub-layer stripes 323 and the fourth sub-layer stripes 324 are sequentially arranged in a staggered manner, each first sub-layer stripe 321 and each second sub-layer stripe 322 are used for forming different coupling-in gratings, and each third sub-layer stripe 323 and each fourth sub-layer stripe 324 are used for forming different coupling-out gratings.

As shown in fig. 12, 22-24, in a fifth possible implementation, a plurality of first nanoparticles are provided to each of the first molecular layer stripes 321 and each of the third molecular layer stripes 323 on the same surface of the optical waveguide 200; providing a plurality of second nanoparticles to each of second sublayer stripes 322 and fourth sublayer stripes 324 on the same surface of optical waveguide 200; each of the first molecular layer stripe 321, each of the second molecular layer stripe 322, each of the third molecular layer stripe 323, and each of the fourth molecular layer stripe 324 are located on the same surface of the optical waveguide 200, and the first nanoparticle and the second nanoparticle have different sizes.

Fig. 22 shows that each of the first molecular layer stripes 321, each of the second molecular layer stripes 322, each of the third molecular layer stripes 323, and each of the fourth molecular layer stripes 324 are located at the first surface 210 of the optical waveguide 200. Fig. 24 shows that each first-sublayer stripe 321, each second-sublayer stripe 322, each third-sublayer stripe 323, and each fourth-sublayer stripe 324 are located on the second surface 220. Fig. 25 shows that the first surface 210 and the second surface 220 each have each first molecular layer stripe 321, each second molecular layer stripe 322, each third molecular layer stripe 323, and each fourth molecular layer stripe 324.

Each of the first molecular layer stripes 321 and each of the third molecular layer stripes 323 may be formed by the same stamp 100, and each of the second molecular layer stripes 322 and each of the fourth molecular layer stripes 324 may be formed by the same stamp 100. There is a second molecular layer stripe 322 between two adjacent first molecular layer stripes 321, and there may be a gap between the first molecular layer stripe 321 and the second molecular layer stripe 322, or the first molecular layer stripe 321 and the second molecular layer stripe 322 are connected. Accordingly, there is a fourth sub-layer stripe 324 between two adjacent third sub-layer stripes 323, and there may be a gap between the third sub-layer stripe 323 and the fourth sub-layer stripe 324, or the third sub-layer stripe 323 and the fourth sub-layer stripe 324 are connected.

The self-assembling molecules 310 are not reacted with other molecules after reacting and linking with the modified molecules 410 on the nanoparticles 400. Thus, in one implementation, the first nanoparticles may be provided first, and the second nanoparticles may be provided to each of the second molecular layer stripes 322 and each of the fourth molecular layer stripes 324 after the first nanoparticles are reacted and connected with each of the first molecular layer stripes 321 and each of the third molecular layer stripes 323. Alternatively, the second nanoparticles may be provided first, and the first nanoparticles may be provided to each of the first molecular layer stripes 321 and each of the third molecular layer stripes 323 after the second nanoparticles are reacted and connected with each of the second molecular layer stripes 322 and each of the fourth molecular layer stripes 324. Thereby, interaction of the self-assembling molecules 310 with the modifying molecules 410 on the nanoparticles 400 is avoided.

Fig. 23 shows spherical nanoparticles 400 (i.e., first nanoparticles) on each first-molecular-layer stripe 321, and quadrangular nanoparticles 400 (i.e., second nanoparticles) on each second-molecular-layer stripe 322.

In a sixth possible implementation, as shown in fig. 12 and 26, a plurality of first nanoparticles are provided to each of the first-molecular-layer stripes 321 and each of the third-molecular-layer stripes 323, and a plurality of second nanoparticles are provided to each of the second-molecular-layer stripes 322 and each of the fourth-molecular-layer stripes 324 on the first surface 210 of the optical waveguide 200.

Providing a plurality of first nanoparticles or a plurality of second nanoparticles to each of first molecular layer stripes 321 and each of third molecular layer stripes 323, and a plurality of third nanoparticles to each of second molecular layer stripes 322 and each of fourth molecular layer stripes 324, on a second surface 220 of optical waveguide 200 opposite first surface 210; wherein the first nanoparticle, the second nanoparticle and the second nanoparticle are all different in size. Thus, there may be four incoupling gratings and four outcoupling gratings on the same optical waveguide 200. In this way, an in-grating and an out-grating that diffract the three colors red, green and blue can be provided on the same optical waveguide 200. Since the intensity of green light is large, there are two incoupling gratings and outcoupling gratings corresponding to green light, and one incoupling grating and outcoupling grating corresponding to red and blue light may be provided.

The embodiment of the application further provides a diffraction grating structure, and the diffraction grating structure is manufactured by the manufacturing method of the diffraction grating structure provided by the embodiment. The structure of the diffraction grating structure is described in detail in the above embodiments, and is not described in detail here.

As shown in fig. 3 to 26, in the present application, the distance between two adjacent nanoparticles 400 in the same molecular layer stripe 320 of the diffraction grating structure is greater than or equal to 0nm and less than or equal to 50nm. If the distance between two adjacent nanoparticles 400 is greater than 100nm, the resonant electromagnetic fields on the particle surfaces of two adjacent nanoparticles 400 cannot be coupled with each other to form a coupled electromagnetic wave mode.

In specific implementation, the shape of the nanoparticle 400 is a regular shape such as a cube, a nanorod or a nanosphere, and the diffraction effect is good by using the nanoparticle 400 with the regular shape.

In addition, the diameter of the nanosphere of the diffraction grating structure provided by the embodiment of the application is more than or equal to 5nm and less than or equal to 100nm. If the diameter of the nanosphere is less than 5nm, the nanoparticle 400 is easily detached after the modified molecules 410 on the nanosphere are connected with the self-assembly molecules 310. If the diameter of the nanosphere is greater than 100nm, it cannot resonate with the red, green and blue input light.

Fig. 27 is a first schematic structural diagram of an imaging device according to an embodiment of the present application; fig. 28 is a schematic structural diagram of an imaging apparatus according to an embodiment of the present application; fig. 29 is a schematic structural diagram three of an imaging apparatus according to an embodiment of the present application; fig. 30 is a schematic structural diagram of an imaging apparatus according to an embodiment of the present application. As shown in fig. 3 to fig. 30, an imaging device 800 is further provided in an embodiment of the present application, and includes an image generation module 700 and at least one diffraction grating structure provided in the foregoing embodiments, where the image generation module 700 is configured to emit light to an incoupling grating of the diffraction grating structure.

Specifically, the image generating module 700 may be a Micro display, such as a Micro LED Micro display, an OLED Micro display, and the like. The image generating module 700 provides input light beams including red, green and blue light beams, and the input light beams of red, green and blue light beams enter the incoupling grating of the diffraction grating structure as emission light, and correspondingly, the diffraction grating structure includes a red incoupling grating 510a, a green incoupling grating 510b, a blue incoupling grating 510c, a red outcoupling grating 520a, a green outcoupling grating 520b and a blue outcoupling grating 520c. The red incoupling grating 510a and the red outcoupling grating 520a diffract the red light beam, and the other color light beams are not diffracted. The green coupling grating 510b and the green outcoupling grating 520b diffract the green color beam, and the remaining color beams are not diffracted. The blue incoupling grating 510c and the blue outcoupling grating 520c diffract the blue light beam, and the remaining color light beams are not diffracted.

The red incoupling grating 510a, the green incoupling grating 510b, the blue incoupling grating 510c, the red outcoupling grating 520a, the green outcoupling grating 520b and the blue outcoupling grating 520c may be disposed on one to three optical waveguides 200. Illustratively, FIG. 27 shows an imaging device 800 having three optical waveguides 200. Fig. 28 and 29 show an imaging device 800 having two optical waveguides 200. Fig. 30 shows an imaging device 800 having one optical waveguide 200. As can be seen from fig. 27 to 30, the less the optical waveguide 200, the thinner the thickness of the entire imaging device 800 is accordingly.

In fig. 27 to 30, arrows represent diffraction of light beams of different colors, solid arrows represent red light beams, broken arrows represent green light beams, and dashed arrows represent blue light beams.

It is to be understood that the structure of the imaging apparatus 800 is not limited to that shown in fig. 27 to 30. After the nanoparticles 400 are sprayed or coated in fig. 16 to 23, 25 and 26, they may be combined so as to diffract red, green and blue light beams, respectively.

Fig. 31 is a schematic structural diagram of a head-mounted device according to an embodiment of the present application. As shown in fig. 31, an embodiment of the present application further provides a head-mounted device, which includes a housing 900 and the imaging apparatus 800 provided in the above embodiment, where the imaging apparatus 800 is disposed on the housing 900.

The head-mounted device can be a device such as glasses or a helmet and other devices with a function of combining a virtual picture with a real scene. The present application is described by taking the example that the head-mounted device may be AR glasses, and it is understood that the specific form of the head-mounted device is not limited to the AR glasses.

The above embodiments are only for illustrating the embodiments of the present invention and are not to be construed as limiting the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made on the basis of the embodiments of the present invention shall be included in the scope of the present invention.

Claims

1. A method for manufacturing a diffraction grating structure, comprising:

processing a seal with a preset pattern; the preset pattern comprises a plurality of grooves arranged at intervals;

printing a plurality of molecular layer stripes matched with the preset pattern on the surface of the optical waveguide through the seal, wherein the self-assembly molecules in the same molecular layer stripe are self-assembled on the surface of the optical waveguide; wherein the molecular layer stripe has a plurality of the self-assembled molecules therein;

providing a plurality of nanoparticles to the surface of the optical waveguide, and patterning and connecting the plurality of nanoparticles on the surface of the molecular layer stripe through the self-assembly molecules, so that the molecular layer stripe and the nanoparticles form a nanoparticle stripe together;

the processing has the seal of predetermineeing the pattern, includes:

processing the seal with two preset patterns on the same surface; a preset distance is reserved between the two preset patterns, and the number of the grooves in the two preset patterns is different;

the printing of a plurality of molecular layer stripes matched with the preset pattern on the surface of the optical waveguide through the stamp comprises the following steps:

printing a plurality of first molecular layer stripes and a plurality of second molecular layer stripes which are respectively matched with the two preset patterns on at least one of two opposite surfaces of the optical waveguide through the stamp; one of the first molecular layer stripes and the second molecular layer stripes is used for forming an incoupling grating, the other is used for forming an outcoupling grating, the distances between the adjacent nanoparticle stripes in different incoupling gratings are different, and the distances between the adjacent nanoparticle stripes in different outcoupling gratings are different.

2. The method of claim 1, wherein each of the self-assembled molecules in the same molecular layer stripe self-assembles on the surface of the optical waveguide, and comprises:

the self-assembly molecules in the same molecular layer stripe are self-assembled on the surface of the optical waveguide, so that the self-assembly molecules are arranged in a patterning mode, and the first functional group of the self-assembly molecules is connected with the surface of the optical waveguide.

3. The method for preparing a diffraction grating structure according to claim 2, wherein the step of providing a plurality of nanoparticles to the surface of the optical waveguide, and the step of patterning and connecting the plurality of nanoparticles to the surface of the optical waveguide by the self-assembly molecules so that the molecular layer stripes and the nanoparticles form nanoparticle stripes together comprises:

spraying or coating a plurality of the nanoparticles having the modification molecules on the surface thereof to the surface of the optical waveguide;

the second functional group of the self-assembly molecule reacts with and is connected with part of the modified molecules on the surface of the nano-particle, so that the molecular layer stripe and the nano-particle jointly form the nano-particle stripe; wherein the self-assembling molecule is attached to the nanoparticle.

4. The method of manufacturing a diffraction grating structure according to claim 2, wherein after the forming of the nano-particle fringes; further comprising:

and covering a protective layer on the surface of the optical waveguide with the nano-particle stripes to protect the nano-particle stripes.

5. The method of manufacturing a diffraction grating structure according to any one of claims 1 to 4, wherein providing a plurality of nanoparticles to the surface of the optical waveguide comprises:

providing a plurality of the nanoparticles to each of the first molecular layer stripes and each of the second molecular layer stripes on the same surface of the optical waveguide, wherein each of the first molecular layer stripes and each of the second molecular layer stripes are on the same surface of the optical waveguide.

6. The method of manufacturing a diffraction grating structure according to any one of claims 1 to 4, wherein providing a plurality of nanoparticles to the surface of the optical waveguide comprises:

providing a plurality of first nanoparticles to each of the first molecular layer stripes and each of the second molecular layer stripes located on the first surface of the optical waveguide;

providing a plurality of second nanoparticles to each of the first molecular layer stripes and each of the second molecular layer stripes on a second surface of the optical waveguide opposite the first surface; wherein the first and second nanoparticles are different in size.

7. The method of manufacturing a diffraction grating structure according to any one of claims 1 to 4, wherein providing a plurality of nanoparticles to the surface of the optical waveguide comprises:

providing a plurality of first nanoparticles to each of the first molecular layer stripes located on the same surface of the optical waveguide;

providing a plurality of second nanoparticles to each of the second molecular layer stripes located on the same surface of the optical waveguide; each of the first molecular layer stripes and each of the second molecular layer stripes are located on the same surface of the optical waveguide, and the first nanoparticles and the second nanoparticles have different sizes.

8. The method of manufacturing a diffraction grating structure according to any one of claims 1 to 4, wherein providing a plurality of nanoparticles to the surface of the optical waveguide comprises:

providing a plurality of first nanoparticles and a plurality of second nanoparticles, respectively, to each of the first molecular layer stripes and each of the second molecular layer stripes located on the first surface of the optical waveguide;

providing a plurality of said second nanoparticles and a plurality of said first nanoparticles to each of said first molecular layer stripes and each of said second molecular layer stripes on a second surface of said optical waveguide opposite said first surface, respectively; wherein the first and second nanoparticles are different in size.

9. The method for manufacturing a diffraction grating structure according to any one of claims 1 to 4, wherein the printing of the plurality of molecular layer stripes matching the predetermined pattern on the surface of the optical waveguide by the stamp includes:

printing a plurality of first molecular layer stripes, a plurality of second molecular layer stripes, a plurality of third molecular layer stripes and a plurality of fourth molecular layer stripes which are respectively matched with the four preset patterns on at least one of two opposite surfaces of the optical waveguide through the stamp; the first molecular layer stripes and the second molecular layer stripes are sequentially arranged in a staggered manner, the third molecular layer stripes and the fourth molecular layer stripes are sequentially arranged in a staggered manner, each first molecular layer stripe and each second molecular layer stripe are used for forming different coupling-in gratings, each third molecular layer stripe and each fourth molecular layer stripe are used for forming different coupling-out gratings, the distances between adjacent nanoparticle stripes in different coupling-in gratings are different, and the distances between adjacent nanoparticle stripes in different coupling-out gratings are different.

10. The method of claim 9, wherein providing a plurality of nanoparticles to a surface of the optical waveguide comprises:

providing a plurality of second nanoparticles to each of the second molecular layer stripes and each of the fourth molecular layer stripes on the same surface of the optical waveguide; each of the first molecular layer stripes, each of the second molecular layer stripes, each of the third molecular layer stripes and each of the fourth molecular layer stripes are located on the same surface of the optical waveguide, and the first nanoparticles and the second nanoparticles have different sizes.

11. The method of claim 9, wherein providing a plurality of nanoparticles to a surface of the optical waveguide comprises:

providing a plurality of first nanoparticles to each of the first molecular layer stripes and each of the third molecular layer stripes on the first surface of the optical waveguide, each of the second molecular layer stripes and each of the fourth molecular layer stripes providing a plurality of second nanoparticles;

providing a plurality of first nanoparticles or a plurality of second nanoparticles to each of the first molecular layer stripes and each of the third molecular layer stripes on a second surface of the optical waveguide opposite the first surface, each of the second molecular layer stripes and each of the fourth molecular layer stripes providing a plurality of third nanoparticles; wherein the first nanoparticle, the second nanoparticle, and the second nanoparticle are all different in size.

12. A diffraction grating structure characterized by being produced by the method for producing a diffraction grating structure according to any one of claims 1 to 11.

13. The diffraction grating structure of claim 12, wherein a spacing between two adjacent nanoparticles in the diffraction grating structure is greater than or equal to 0nm and less than or equal to 50nm.

14. The diffraction grating structure of claim 13, wherein the nanoparticles are in the shape of cubes, nanopillars, or nanospheres.

15. The diffraction grating structure of claim 14, wherein the nanosphere has a diameter of greater than or equal to 5nm and less than or equal to 100nm.

16. An imaging device comprising at least one diffraction grating structure according to any one of claims 12 to 15 and an image generating module for emitting light towards an incoupling grating of said diffraction grating structure.

17. A headset comprising a housing and the imaging device of claim 16, the imaging device being disposed on the housing.