阅读说明：本技术 一种体全息片及制备方法以及在瞄准装置的用途 (Volume hologram, preparation method and application in aiming device ) 是由 朱兵兵 董英琴 于 2021-07-27 设计创作，主要内容包括：本发明主要涉及一种体全息片及制备方法以及在瞄准装置的用途,利用光折变玻璃制备表面光滑的体全息片,因为光热折变玻璃材料具有极佳的温度稳定性、体全息片具有高数据冗余特性以及高角度选择性,可以很好地解决上述全息枪瞄重的工艺中成本高、清晰度不够、环境稳定性欠佳的问题。(The invention mainly relates to a volume hologram, a preparation method and application in a sighting device, and the volume hologram with a smooth surface is prepared by using photo-thermal conversion glass, because photo-thermal conversion glass material has excellent temperature stability, the volume hologram has high data redundancy characteristic and high angle selectivity, the problems of high cost, insufficient definition and poor environmental stability in the holographic gun sighting process can be well solved.)

1. The preparation method of the volume hologram is characterized by comprising the preparation of photothermal conversion glass and the preparation of volume grating;

the preparation of the photothermal conversion glass comprises the following steps,

the burdening process comprises the following steps: weighing, grinding and stirring glass raw materials according to a specific ratio to fully mix the glass raw materials, wherein the glass raw materials and the ratio thereof are

SiO₂，50～60％；

B₂O₃，2～6％；

Al₂O₃，5～12％；

Li₂O₆，20％；

ZrO₂+TiO₂，2～5％；

AgCl，0.001～0.5％；

Na₂O+K₂O，1～15％；

InF₃，3～10％；

The glass smelting process comprises the following steps: adding the ingredient powder into a quartz crucible in batches to melt the mixture into glassy clinker;

clarification and homogenization process: adding the glassy clinker into a platinum crucible and stirring to clarify and homogenize the glass;

the annealing process comprises the following steps: pouring the homogenized glass material into a grinding tool, and putting the grinding tool into a rocking furnace for annealing;

preparing the volume grating: and cutting and polishing the prepared photo-thermal conversion glass into a body holographic recording glass sheet with the thickness required by the body grating, and then preparing the body grating.

2. The method for preparing a volume hologram according to claim 1, wherein the volume grating is prepared by: the method comprises the following steps of preparing the optical grating by adopting a first integral optical grating preparation device, wherein the first integral optical grating preparation device comprises an exposure light source, a polarization beam splitter prism, a reflective spatial light modulator, a control driving system of the reflective spatial light modulator, a first beam expanding and collimating device, a volume hologram recording sheet, a total reflector and a second beam expanding and collimating device;

the polarization beam splitter prism divides the light emitted by the exposure light source into two beams of P light and S light with different polarization directions; the P light penetrates through the polarization beam splitting prism and then sequentially passes through the total reflection mirror and the second beam expanding collimation device to reach the volume holographic recording glass sheet; the S light is reflected to the reflective spatial light modulator through the polarization beam splitter prism, and after modulation, the S light sequentially penetrates through the polarization beam splitter prism and the first beam expanding collimation device to reach the volume holographic recording glass sheet, interference fringes generated by two dry light beams are recorded on the volume holographic recording glass sheet, and then the volume holographic recording glass sheet is subjected to heat treatment to obtain a required volume holographic sheet, wherein the temperature of the heat treatment is 500-600 ℃.

3. The method for preparing a volume hologram according to claim 1, wherein the volume grating is prepared by: preparing by adopting a second volume grating preparation device, wherein the second volume grating preparation device comprises an exposure light source, a polarization beam splitter prism, a transmission type spatial light modulator, a control driving system of the transmission type spatial light modulator, a first beam expanding and collimating device and a volume holographic recording sheet;

the polarization beam splitter prism divides light emitted by the exposure light source into P light and S light, the S light is reflected to the transmission type spatial light modulator through the polarization beam splitter prism, is adjusted to be calculated in advance and is stored in an interference pattern in a control driving system to be emitted, and the interference pattern reaches the volume hologram recording sheet through the first beam expanding collimation device.

4. The method as claimed in claim 3, wherein the second volume grating manufacturing apparatus further comprises a light absorbing device, and the P light is absorbed by the light absorbing device after passing through the polarization splitting prism.

5. The method for preparing a volume hologram according to any one of claims 2 to 4, wherein said exposure light source is an ultraviolet laser light source.

6. A volume hologram, which is produced by the method for producing a volume hologram according to any one of claims 1 to 5.

7. The application of the volume hologram on the aiming device is characterized in that the aiming device comprises a light source, a third beam expanding and collimating device, a reflecting prism, a grating and the volume hologram;

the light source is a semiconductor laser with a visible light waveband;

the third beam expanding and collimating device comprises a beam expanding lens, a collimating lens and a polaroid;

the reflecting prism comprises two reflecting surfaces;

the volume hologram of claim 6;

and the light beam emitted by the light source sequentially passes through the third beam expanding and collimating device, the reflecting prism and the grating, then obliquely enters the first surface of the volume hologram and is emitted out in parallel from the second surface.

8. The use of a volume hologram according to claim 7, further comprising a light absorbing sheet, said light absorbing sheet being positioned above said volume hologram.

9. The use of a volume hologram according to claim 8, wherein said light absorbing sheet is a rough-surfaced black material having light absorbing properties.

10. Use of a volume hologram according to any of claims 7 to 9, wherein the angle between the light incident on said volume hologram and the normal to the first surface of said volume hologram is between 20 ° and 60 °.

Technical Field

The invention relates to the technical field of aiming equipment, in particular to a volume hologram, a preparation method and application thereof in an aiming device.

Background

Since the holography of 1948, this particular wavefront recording and reproducing technique rapidly emits light and heat in various fields. The holographic sighting telescope is one of applications of holographic technology in the field of weapons, among numerous sighting products, the holographic sighting telescope is a younger generation product, is arranged by multinational troops due to the characteristics of high speed and high sighting precision, and is mainly used for short-distance operations of armed police and special polices, sighting in a maritime bumpy environment, ground shooting in an airborne process and the like under the conditions of high speed and high precision sighting. As one of the important elements of the surface collimating mirror, the scientists have developed hologram sheets of various materials so far, and the preparation methods are also various. The hologram has the following characteristics: the system can store all information of object light waves and reproduce a three-dimensional image of an object under a characteristic condition; secondly, all the information of the object appearance is recorded at each part of the hologram, so that even if the hologram is broken, a small piece of hologram is left and the whole image can still be restored; and a plurality of wave surfaces can be stored on the same hologram, so that images can be restored from different angles.

The holography technique is mainly divided into two steps, namely, the recording of optical information (amplitude and phase) emitted from an object and the reproduction of an object image. In most conventional optical holography, interference information is recorded mainly using photosensitive films such as dichromated gelatin, silver halide, and the like. The fine laser beam output by the laser is reflected by the reflector and then divided into two beams by the beam splitter: one beam reflected is reflected again by the reflector and expanded by the beam expander and then irradiates the holographic dry plate; one transmitted beam is reflected and refracted by the reflector, expanded by the beam expander and used for illuminating an object, and an object beam formed by diffuse reflection of the object also reaches the holographic dry plate. As with the previous film cameras, processing steps (including development, fixing, washing, drying, etc.) are required after recording, which is time consuming and labor intensive. In recent years, researches on holographic materials, such as photorefractive crystals, photopolymers, optothermal conductive plastics, etc., have been advanced, and these materials not only can omit chemical treatment, but also have high storage capacity and diffraction efficiency, and even some materials can be repeatedly erased and recorded. However, the preparation cost of some special materials is too high, the process is too complex, and the phenomenon that the gun is more expensive than a gun appears at one time.

In the field of weapon application, the requirements on the thermal stability of the device are extremely high, the device is required to meet the temperature use range of-40-65 ℃, in addition, for a holographic film in a gun sight, the light transmittance is required to be high, the definition of a generated image is high, and the conventional holographic gun sight in the current market has the defects of low light transmittance, unclear image edge, poor stability and overhigh cost.

It includes photosensitive emulsion layer, bottom, piece base layer and anti-halation layer to disclose a holographic board structure of doing in patent CN 109307986A, the piece basic unit does photosensitive emulsion layer's supporter, photosensitive emulsion layer passes through the bottom is adhered to on the piece basic unit, anti-halation layer coats in the back of piece basic unit, and the not good and luminousness of latex class optical device heat stability is low, the visibility of the holographic image of influence that can be great.

Patent CN 101533257a discloses a hologram substrate and a method for manufacturing the hologram substrate, which mainly uses a mold pressing method to press a computer generated hologram pattern onto a deformable resin hologram material, the surface of the hologram substrate generated by the method has a concave-convex structure, the edge angle of the concave-convex edge causes scattering, thereby reducing the visibility of the hologram image and having a high requirement for cleanliness of the use environment.

A holographic recording material, a holographic recording backplane and uses thereof are disclosed in patent CN 104109217B. The holographic recording material comprises 6-60% of zinc sulfide nanoparticles, 0.2-10% of photoinitiator and the balance of mixed photopolymerization monomer according to the mass ratio, wherein the average particle size of the zinc sulfide nanoparticles is 1-50 nanometers, and the problems of high synthesis cost of the nanoparticles, complicated post-treatment or poor dispersibility are known.

In order to solve the above problems, the present applicant proposed a volume hologram and a method for manufacturing the same.

Disclosure of Invention

The invention aims to provide a preparation method based on a volume hologram, which utilizes photorefractive glass to prepare the volume hologram with a smooth surface, and can well solve the problems of high cost, insufficient definition and poor environmental stability in the holographic gun aiming process because the photothermal refraction glass material has excellent temperature stability, the volume hologram has high data redundancy characteristic and high angle selectivity.

A method for preparing volume hologram includes preparing photo-thermal conversion glass and preparing volume grating;

the preparation of the photothermal conversion glass comprises the following steps,

the burdening process comprises the following steps: weighing, grinding and stirring glass raw materials according to a specific ratio to fully mix the glass raw materials, wherein the glass raw materials and the ratio thereof are

SiO₂，50～60％；

B₂O₃，2～6％；

Al₂O₃，5～12％；

Li₂O₆，20％；

ZrO₂+TiO₂，2～5％；

AgCl，0.001～0.5％；

Na₂O+K₂O，1～15％；

InF₃，3～10％；

The glass smelting process comprises the following steps: adding the ingredient powder into a quartz crucible in batches to melt the mixture into glassy clinker;

clarification and homogenization process: adding the glassy clinker into a platinum crucible and stirring to clarify and homogenize the glass;

the annealing process comprises the following steps: pouring the homogenized glass material into a grinding tool, and putting the grinding tool into a rocking furnace for annealing;

using AgCl as a photosensitizer, adopting ultraviolet light exposure, forming Ag atoms through Ag + sensitization, carrying out heat treatment at 500-600 ℃, polymerizing the Ag atoms into a seed crystal nucleus, and inducing InF₃Generation of primary crystal phase to induce again [ Li₂O·2SiO₂]And generating a crystalline phase to separate out a composite crystalline phase on the exposed area, so that the refractive index of the exposed area is increased, and the refractive index of the unexposed area is not changed, so that the exposed area and the unexposed area generate a refractive index modulation degree, and the holographic pattern is recorded.

Preparing the volume grating: and cutting and polishing the prepared photo-thermal conversion glass into a body holographic recording glass sheet with the thickness required by the body grating, and then preparing the body grating.

Specifically, the preparation of the volume grating is as follows: the method comprises the following steps of preparing the optical grating by adopting a first integral optical grating preparation device, wherein the first integral optical grating preparation device comprises an exposure light source, a polarization beam splitter prism, a reflective spatial light modulator, a control driving system of the reflective spatial light modulator, a first beam expanding and collimating device, a volume hologram recording sheet, a total reflector and a second beam expanding and collimating device;

the polarization beam splitter prism divides the light emitted by the exposure light source into two beams of P light and S light with different polarization directions; the P light penetrates through the polarization beam splitting prism and then sequentially passes through the total reflection mirror and the second beam expanding collimation device to reach the volume holographic recording glass sheet; the S light is reflected to the reflective spatial light modulator through the polarization beam splitter prism, and after modulation, the S light sequentially penetrates through the polarization beam splitter prism and the first beam expanding collimation device to reach the volume holographic recording glass sheet, interference fringes generated by two dry light beams are recorded on the volume holographic recording glass sheet, and then the volume holographic recording glass sheet is subjected to heat treatment to obtain a required volume holographic sheet, wherein the temperature of the heat treatment is 500-600 ℃.

In addition, the preparation of the volume grating can also adopt a second volume grating preparation device to prepare, wherein the second volume grating preparation device comprises an exposure light source, a polarization beam splitter prism, a transmission type spatial light modulator, a control driving system of the transmission type spatial light modulator, a first beam expanding collimation device and a volume holographic recording sheet;

the polarization beam splitter prism divides light emitted by the exposure light source into P light and S light, the S light is reflected to the transmission type spatial light modulator through the polarization beam splitter prism, is adjusted to be calculated in advance and is stored in an interference pattern in a control driving system to be emitted, and the interference pattern reaches the volume hologram recording sheet through the first beam expanding collimation device.

Preferably, the second volume grating preparation device further comprises a light absorption device, and the P light is absorbed by the light absorption device after passing through the polarization splitting prism.

Preferably, the exposure light source is an ultraviolet laser light source.

The second purpose of the invention is to provide a volume hologram, which is prepared by the preparation method.

The third purpose of the invention is to provide an application of the volume hologram on the aiming device, the aiming device comprises a light source, a third beam expanding and collimating device, a reflecting prism, a grating and the volume hologram;

the light source is a semiconductor laser with a visible light waveband;

the third beam expanding and collimating device comprises a beam expanding lens, a collimating lens and a polaroid;

the reflecting prism comprises two reflecting surfaces;

the volume hologram is prepared by the preparation method;

and the light beam emitted by the light source sequentially passes through the third beam expanding and collimating device, the reflecting prism and the grating, then obliquely enters the first surface of the volume hologram and is emitted out in parallel from the second surface.

Preferably, the holographic optical film further comprises an optical absorption sheet, wherein the optical absorption sheet is positioned above the volume holographic sheet, and part of light is reflected to the optical absorption sheet from the first surface of the holographic sheet, so that light is prevented from leaking. Specifically, the light absorbing sheet is a rough-surface black substance with light absorption characteristics.

Further, the included angle between the light incident to the volume hologram and the normal of the first surface of the volume hologram is 20-60 °.

Compared with the prior art, the volume hologram, the preparation method and the application in the aiming device of the invention also have the following advantages:

(1) compared with an etching or mould pressing mode, the diffraction holographic plate prepared from the glass material has the advantages that the surface of a device is smooth, edge scattering noise is reduced, and image definition is improved;

(2) because PRT glass material is adopted, the heat resistance and the shock resistance of the holographic plate are far better than those of materials such as resin, latex, polymer and the like;

(3) the spatial light modulator is adopted to generate object light or interference patterns, compared with the traditional mask plate to generate the interference patterns, the production cost is saved, and compared with a thin film holographic plate, the volume holographic plate is also beneficial to multi-volume holographic recording.

Drawings

Fig. 1 is a schematic structural view of an aiming device in embodiment 1;

FIG. 2 is a graph of an aiming division recoverable by a volume hologram in example 1;

FIG. 3 is a schematic structural view of a first bulk optical grating production apparatus according to example 1;

fig. 4 is a schematic structural view of a second bulk grating production apparatus in example 2.

Detailed Description

The invention is further described below with reference to the following figures and specific examples.

Example 1

As shown in fig. 1, the aiming device comprises a light source 1, a third beam expanding and collimating device 2, a reflecting prism 3, a grating 4, a volume hologram 5 and a light absorbing sheet 6; the light beam emitted by the light source 1 sequentially passes through the third beam expanding and collimating device 2, the reflecting prism 3 and the grating 4, then enters the first surface of the volume hologram 5 at an inclined angle and is emitted from the second surface in parallel, so that the human eye can see the restored image 7 of the hologram recorded in the volume hologram 5 through the second surface of the volume hologram 5, and in addition, part of the light is reflected to the light absorption sheet 6 from the first surface of the volume hologram 5, and light leakage is avoided.

The light source 1 is a semiconductor laser with a visible light wave band of 532 nm;

the third beam expanding and collimating device 2 comprises a beam expanding lens, a collimating lens and a polaroid and has the functions of expanding beams, collimating and filtering;

the reflecting prism 3 comprises two reflecting surfaces;

the light absorbing sheet 6 is a rough black substance with good light absorption characteristic and can be plastic or painted metal;

and the included angle theta between the light rays incident to the volume hologram and the normal line of the surface of the volume hologram is 35 degrees.

A method for preparing volume hologram mainly comprises two steps, namely preparing photothermal conversion glass (also called laser holographic recording glass) and preparing volume grating.

The working principle is as follows: a volume hologram on which interference fringes of an object are recorded is diffraction-reproduced using a light wave of a specific wavelength.

The preparation of the photothermal conversion glass comprises the following steps: proportioning, smelting glass, clarifying, homogenizing and annealing.

The burdening process comprises the following steps: the glass raw materials are weighed according to a specific proportion, ground and stirred to be fully mixed. The patent uses the ingredients and the proportion is

SiO₂，55％；

B₂O₃，4％；

Al₂O₃，5％；

Li₂O₆，20％；

ZrO₂+TiO₂，4％；

AgCl，0.5％；

Na₂O+K₂O，6.5％；

InF₃，5％

The glass melting process comprises the following steps: adding the ingredient powder into a quartz crucible in batches at a certain temperature to melt the mixture into glassy clinker.

The clarification and homogenization process: adding the glassy clinker into a platinum crucible with a specific size and a specific structure, and stirring to clarify and homogenize the glass;

the annealing process comprises the following steps: and pouring the homogenized glass material into a grinding tool, and putting the grinding tool into a rocking furnace for annealing at a specific temperature.

The prepared photothermal conversion glass is cut and polished into a bulk grating-required thickness-formed holographic recording glass sheet, and the bulk grating can be prepared.

The scheme uses AgCl as a photosensitizer, adopts ultraviolet light exposure, Ag + sensitization forms Ag atoms, and the Ag atoms are polymerized into a seed crystal nucleus through heat treatment at 500-600 ℃ to induce InF₃Generation of primary crystal phase to induce again [ Li₂O·2SiO₂]And generating a crystalline phase to separate out a composite crystalline phase on the exposed area, so that the refractive index of the exposed area is increased, and the refractive index of the unexposed area is not changed, so that the exposed area and the unexposed area generate a refractive index modulation degree, and the holographic pattern is recorded.

One way of making the volume grating is as follows:

as shown in fig. 3, which is a schematic structural diagram of a first integrated grating manufacturing apparatus, the first integrated grating manufacturing apparatus includes an exposure light source 9, a polarization beam splitter prism 11, a reflective spatial light modulator 10, a control driving system 8 of the spatial light modulator, a first beam expanding and collimating device 12, a volume hologram recording sheet 13, a total reflector 14, and a second beam expanding and collimating device 15;

the working principle is as follows: the polarization beam splitter prism 11 splits the ultraviolet light emitted by the exposure light source into two beams of light with different polarization directions, namely P light and S light; the P light penetrates through the polarization beam splitter prism 11 and sequentially passes through the total reflector 14 and the second beam expanding collimation device 15 to reach the volume hologram recording sheet 13, the S light is reflected to the reflective spatial light modulator 10 through the polarization beam splitter prism 11, the P light modulated into a pattern with a specific phase is emitted and reaches the volume hologram recording sheet 13 through the polarization beam splitter prism 11 and the first beam expanding collimation device 12, interference fringes generated by the two dry light beams are recorded on the volume hologram recording sheet, and then the volume hologram recording sheet 13 is subjected to heat treatment to obtain a required volume hologram.

The exposure light source 9 is an ultraviolet laser light source (the wavelength is about 325 nm);

the heat treatment temperature is 500-600 ℃.

Example 2

This example differs from example 1 in the way the volume grating is prepared,

the ingredients used in the embodiment are as follows

SiO₂，55％；

B₂O₃，5.8％；

Al₂O₃，3.2％；

Li₂O₆，20％；

ZrO₂+TiO₂，4％；

AgCl，0.5％；

Na₂O+K₂O，6％；

InF₃，5.5％

The preparation method of the glass is the same as that of the first embodiment;

fig. 4 is a schematic structural diagram of a second volume grating preparation apparatus, and the structure includes an exposure light source 9, a polarization beam splitter prism 11, a transmissive spatial light modulator 18, a control driving system 8 of the transmissive spatial light modulator, a first beam expanding and collimating device 12, a volume hologram recording sheet 13, and a light absorbing device 16;

the working principle is as follows: the polarization beam splitter prism 11 splits the light emitted by the exposure light source 9 into P light and S light, the S light is reflected to the transmissive spatial light modulator 18 through the polarization beam splitter prism 11, is adjusted to be calculated in advance and is emitted out through an interference pattern stored in a control driving system 17 of the transmissive spatial light modulator, and reaches the volume hologram recording sheet 13 through the first beam expanding collimation device 12, and the P light is absorbed by the light absorption device 16 after passing through the polarization beam splitter prism 11.

In the description of the present specification, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of describing the technical solutions of the present patent and for simplification of the description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be interpreted as limiting the present patent application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this patent application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this specification, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "fixed" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integral to one another; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present specification can be understood by those of ordinary skill in the art as appropriate.

In this specification, unless explicitly stated or limited otherwise, a first feature may be "on" or "under" a second feature such that the first and second features are in direct contact, or the first and second features are in indirect contact via an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.