Intermediate infrared liquid crystal optical phased array based on CIO conductive thin film and preparation method of intermediate infrared liquid crystal optical phased array

Abstract

The invention discloses an intermediate infrared liquid crystal optical phased array based on a CIO conductive film and a preparation method of the intermediate infrared liquid crystal optical phased array, relates to a liquid crystal optical phased array technology, and aims at solving the problem that an existing liquid crystal optical phased array is low in transmittance in an intermediate infrared band. The intermediate infrared liquid crystal optical phased array comprises an upper substrate assembly, a liquid crystal molecular layer and a lower substrate assembly; the upper substrate assembly comprises an upper substrate outer surface intermediate infrared antireflection film, an upper substrate, an upper substrate inner surface intermediate infrared antireflection film, an upper CIO common electrode layer and an upper orientation layer. The lower substrate assembly comprises a lower orientation layer, a lower CIO electrode layer, a lower substrate inner surface intermediate infrared antireflection film, a lower substrate and a lower substrate outer surface intermediate infrared antireflection film. Compared with a common liquid crystal optical phased array based on an ITO conductive film, the liquid crystal optical phased array based on the CIO conductive film and the intermediate infrared antireflection film has higher transmittance in the intermediate infrared band, and the light loss of the whole liquid crystal phased array can be effectively reduced.

Description

Technical Field

[0001] The present invention belongs to the field of space optical communication technology, relates to liquid crystal optical phased array technology, and in particular to a mid-infrared liquid crystal optical phased array based on a CIO conductive film and a preparation method thereof. Background Art

[0002] With the rapid development of infrared technology, the demand for infrared products in aerospace, modern military and other fields has gradually shifted to higher quality and higher precision, and the demand for related products has grown rapidly. The continuous advancement of military-civilian integration has required products with high quality and low cost after infrared technology is applied to the military field. As an important component of the laser radar scanning system, the liquid crystal optical phased array has the advantages of small size, light weight, fast response speed, high resolution, and programmable control. The mid-infrared 3-5 micron band is an important atmospheric window, and it is also the main working area of ​​military infrared detectors and infrared guidance systems. As the most advanced non-mechanical beam scanning technology, the beam scanning technology of the mid-infrared liquid crystal optical phased array uses mid-infrared liquid crystal as its functional material, which can expand the phased beam scanning technology to the mid-infrared band of 3-5 microns, and can solve the problems of fast angle switching and high-precision pointing of far-infrared laser radar.

[0003] The invention patent application with application number 202211505305.9 discloses a liquid crystal optical phased array device that can withstand laser power and a method for preparing the same. The phased array device includes, from bottom to top, a substrate, an array electrode layer, an orientation layer, a liquid crystal layer, an orientation layer, a conductive layer, and a substrate; a sub-wavelength array hole structure is provided on each electrode of the array electrode layer and on the conductive layer.

[0004] The invention patent application with application number 202311244043.X also discloses a liquid crystal optical phased array with a high filling ratio, which includes a first anti-reflection film, a first substrate, a first liquid crystal molecule layer, a second substrate, a second liquid crystal molecule layer, a third substrate and a second anti-reflection film stacked in sequence from top to bottom, the first substrate includes a first glass substrate, a first ITO electrode layer and a first PI orientation layer, the second substrate includes a second PI orientation layer, an ITO electrode array A, a second glass substrate, an ITO electrode array B and a third PI orientation layer arranged from top to bottom, the third substrate includes a fourth PI orientation layer, a second ITO electrode and a third glass substrate distributed in sequence from top to bottom, the first PI, the second PI, the third PI and the fourth PI orientation layers constitute the PI orientation layers respectively, the electrode arrays A and B are located on the front and back sides of the second glass substrate, and are cross-distributed in space.

[0005] As in the above-mentioned invention patent, the conductive films in the existing liquid crystal optical phased array are mostly indium tin oxide (ITO) transparent conductive films. According to research, the transmittance of ITO conductive film is closely related to the thickness of the film. The optical transmittance of ITO conductive films of different thicknesses is different. Even the ITO film with a thickness of 50nm has a transmittance of less than 90% in the near-infrared band. In the prior art, there are also new conductive film materials. For example, some people have proposed to use the high transmittance advantage of graphene in the infrared band to replace the traditional ITO film, but the electrode lithography of graphene is a very difficult problem; some people have proposed to use organic polymer conductive films (such as ethylenedioxythiophene / sodium polyvinyl sulfonate (PEDOT: PSS)) to prepare conductive films, but its high transmittance is also mainly limited to the visible light band. Therefore, it is necessary to propose a new conductive film material so that the film material prepared by it can have a higher transmittance in the mid-infrared band. Summary of the invention

[0006] The purpose of the present invention is to solve the problem of low transmittance of existing liquid crystal optical phased arrays in the mid-infrared band, to provide a mid-infrared liquid crystal optical phased array based on CIO conductive film and a preparation method thereof, so as to improve the transmittance and multi-beam capability of the overall phased array in the mid-infrared band.

[0007] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions: A mid-infrared liquid crystal optical phased array based on a CIO conductive film comprises: an upper substrate assembly, a liquid crystal molecule layer and a lower substrate assembly arranged in sequence from top to bottom; The upper substrate assembly includes: a mid-infrared anti-reflection film on the outer surface of the upper substrate, an upper substrate, a mid-infrared anti-reflection film on the inner surface of the upper substrate, an upper CIO common electrode layer and an upper orientation layer arranged in sequence from top to bottom; The lower substrate assembly includes: a lower orientation layer, a lower CIO electrode layer, a mid-infrared anti-reflection film on the inner surface of the lower substrate, a lower substrate, and a mid-infrared anti-reflection film on the outer surface of the lower substrate, which are arranged in sequence from top to bottom.

[0008] Furthermore, it also includes a frame glue located outside the liquid crystal molecule layer, and the upper substrate assembly and the lower substrate assembly are sealed and packaged by the frame glue.

[0009] Furthermore, the frame glue is doped with spacers, and the upper substrate assembly and the lower substrate assembly are supported by the spacers.

[0010] Furthermore, the spacer is used to control the thickness of the liquid crystal molecule layer, and the size of the spacer is determined according to the birefringence difference of the liquid crystal material in the liquid crystal molecule layer, and the product of the birefringence difference of the liquid crystal material in the liquid crystal molecule layer and the thickness of the liquid crystal molecule layer is greater than the wavelength of the working electromagnetic wave used.

[0011] Further, the alignment direction of the alignment film layer of the upper alignment layer is opposite to the alignment direction of the alignment film layer of the lower alignment layer.

[0012] Furthermore, the lower CIO electrode layer includes a plurality of CIO grating electrodes arranged at intervals, each CIO grating electrode is connected to the communication driving chip on the lower substrate, and the voltage on each CIO grating electrode is independently regulated by the communication driving chip.

[0013] Furthermore, the voltage applied to the CIO grating electrode is regulated by the communication driver chip to change the electric field distribution in the space where the liquid crystal molecular layer is located, drive the liquid crystal molecules in the liquid crystal molecular layer to rotate, and cause the phase delay of light to change when passing through the liquid crystal molecules.

[0014] Furthermore, the CIO grating electrode is manufactured by wet method, dry method, magnetron sputtering or CNC engraving.

[0015] Furthermore, the lower substrate includes four sub-aperture areas that are independently controlled from each other.

[0016] A method for preparing a mid-infrared liquid crystal optical phased array based on a CIO conductive film comprises the following steps: Step 1, cleaning; Clean the upper substrate and lower substrate to be plated; Step 2, coating; Depositing a mid-infrared anti-reflection film on the outer surface of the upper substrate and a mid-infrared anti-reflection film on the outer surface of the lower substrate on the back of the upper substrate and the lower substrate respectively; Depositing a mid-infrared anti-reflection film on the inner surface of the upper substrate and a mid-infrared anti-reflection film on the inner surface of the lower substrate on the front surfaces of the upper substrate and the lower substrate respectively; Depositing an upper CIO common electrode layer and a lower CIO electrode layer on the mid-infrared anti-reflection film on the inner surface of the upper substrate and the mid-infrared anti-reflection film on the inner surface of the lower substrate respectively; Step 3, photolithography; The pattern on the mask is transferred to the lower substrate coated with the film layer by using photoresist as a medium, and a layer of photoresist pattern having the same pattern as the mask is formed on the lower substrate; Step 4, etching; The areas on the lower substrate not protected by the photoresist are etched away by an etching process to obtain a CIO grating electrode; a plurality of CIO grating electrodes arranged at intervals form a lower CIO electrode layer; Step 5, preparing an alignment layer; Coating polyimide on the upper substrate with the prepared electrodes, and preparing an upper liquid crystal alignment layer by means of rubbing alignment or photo-alignment; Coating polyimide on the lower substrate with the prepared electrodes, and preparing a lower liquid crystal alignment layer by means of rubbing alignment or photo-alignment; Setting the alignment directions of the upper liquid crystal alignment layer on the upper substrate and the lower liquid crystal alignment layer on the lower substrate to be anti-parallel; Step 6, pressing the box and filling the wafer; The upper substrate and the lower substrate are attached by using a frame glue, and spacers are added into the frame glue; and then liquid crystal is poured into the area between the frame glue, the upper substrate and the lower substrate by using the siphon effect to form a liquid crystal layer.

[0017] The beneficial effects of the present invention are as follows: 1. In the present invention, a CIO transparent conductive film is used as the conductive film, and a mid-infrared anti-reflection film is provided in the upper and lower substrates; compared with the common liquid crystal optical phased array based on ITO conductive film, the liquid crystal optical phased array based on CIO conductive film and mid-infrared anti-reflection film of the present application has a higher transmittance in the mid-infrared band (the transmittance of ITO conductive film in the mid-infrared is generally not higher than 30%, while the transmittance of CIO conductive film in the mid-infrared of the present application is more than 50%), which can effectively reduce the light loss of the entire liquid crystal phased array.

[0018] 2. The present invention, on the basis of introducing CIO conductive film to replace the traditional ITO conductive film as the phased array power supply film layer, also adopts a mid-infrared high-transmittance substrate to replace ordinary glass as the substrate, and adds a mid-infrared high-transmittance optical anti-reflection film layer on the upper and lower surfaces of the substrate, and uses a new mid-infrared high-transmittance liquid crystal material. Compared with the traditional liquid crystal phased array based on ITO conductive film, it can effectively reduce the optical loss in the mid-infrared, and can integrate multiple independent control areas in a single device, which can be used by multiple users at the same time. The mid-infrared liquid crystal optical phased array has the advantages of high transmittance, fast response speed, simple drive control, and high integration in the mid-infrared band.

[0019] 3. In the present invention, based on the modulation principle of the transmissive liquid crystal spatial light modulator, the one-dimensional deflection angle of the outgoing light is regulated by changing the thickness of the liquid crystal layer and the loading voltage of the array electrode, so that the liquid crystal optical phased array has the advantages of high transmittance, fast response speed, simple driving control, etc.

[0020] 4. In the present invention, the upper and lower substrates are sealed and packaged by frame glue, and spacers are sprayed in the frame glue. The upper and lower substrates are supported by the spacers in the frame glue, so that the size of the spacers can be adjusted according to the refractive index of the liquid crystal material, and the thickness of the liquid crystal molecule layer of the array liquid crystal device is controlled by the size of the spacers, and finally the product of the birefringence difference of the liquid crystal molecule layer and the thickness of the liquid crystal layer is made greater than the wavelength of the working electromagnetic wave used. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structural cross section of the present invention; Figure 2It is a schematic diagram of the lower substrate grating electrode structure of the present invention; Among them, the figure markings are: 1-mid-infrared anti-reflection film on the outer surface of the upper substrate; 2-upper substrate; 3-mid-infrared anti-reflection film on the inner surface of the upper substrate; 4-upper CIO common electrode layer; 5-upper orientation layer; 6-liquid crystal molecule layer; 7-spacer; 8-lower orientation layer; 9-CIO grating electrode; 10-mid-infrared anti-reflection film on the inner surface of the lower substrate; 11-lower substrate; 12-mid-infrared anti-reflection film on the outer surface of the lower substrate; 13-communication driver chip; 14-frame glue. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0023] Therefore, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0024] Embodiment 1: This embodiment provides a multi-user mid-infrared liquid crystal optical phased array based on CIO conductive film. From the perspective of device design, CIO conductive film is selected as the power supply film layer, sapphire with high mid-infrared transmittance is used as the substrate material, and mid-infrared anti-reflection film is plated on both sides of the substrate to improve the transmittance of the overall phased array and improve the related performance of the overall phased array.

[0025] The multi-user mid-infrared liquid crystal optical phased array includes: an upper substrate assembly, a liquid crystal molecular layer 6 and a lower substrate assembly. The liquid crystal molecular layer 6 is located between the upper substrate assembly and the lower substrate assembly. The edges of the upper substrate assembly and the lower substrate assembly are sealed and packaged, aligned, fitted and cured, and spacers 7 are added to adjust the thickness, so as to form a liquid crystal layer with a stable thickness between the upper substrate assembly and the lower substrate assembly.

[0026] The upper substrate assembly includes, from top to bottom, a mid-infrared anti-reflection film 1 on the outer surface of the upper substrate, an upper substrate 2, a mid-infrared anti-reflection film 3 on the inner surface of the upper substrate, an upper CIO common electrode layer 4 and an upper orientation layer 5.

[0027] The lower substrate assembly includes, from top to bottom, a lower orientation layer 8, a lower CIO electrode layer 9, a mid-infrared anti-reflection film 10 on the inner surface of the lower substrate, a lower substrate 11, and a mid-infrared anti-reflection film 12 on the outer surface of the lower substrate.

[0028] The upper substrate assembly and the lower substrate assembly are sealed and packaged by a frame glue 14, and spacers 7 are doped in the frame glue 14. The upper substrate assembly and the lower substrate assembly are supported by the spacers 7. The size of the spacers 7 is determined according to the birefringence of the liquid crystal material, and the product of the birefringence difference of the liquid crystal material in the liquid crystal molecule layer 6 and the thickness of the liquid crystal molecule layer 6 is greater than the wavelength of the working electromagnetic wave used; the spacers 7 are used to control the thickness of the liquid crystal molecule layer so that the liquid crystal molecule layer achieves a phase shift of 2π.

[0029] The orientation direction of the orientation film layer of the upper orientation layer 5 is opposite to that of the orientation film layer of the lower orientation layer 8 , and the orientation can be performed by friction or photo-anchoring during the preparation process.

[0030] The lower CIO electrode layer includes a plurality of CIO grating electrodes 9 arranged at intervals, each CIO grating electrode 9 is connected to the communication driving chip 13 on the lower substrate 11, and the voltage on each CIO grating electrode 9 is independently regulated by the communication driving chip 13. The communication driving chip 13 regulates the voltage applied to the CIO grating electrode 9, changes the electric field distribution in the space where the liquid crystal molecule layer 6 is located, drives the liquid crystal molecules in the liquid crystal molecule layer 6 to rotate, and causes the phase delay change of light when passing through the liquid crystal molecules. In addition, the CIO grating electrode 9 can be made by wet method, dry method, magnetron sputtering or CNC engraving.

[0031] In order to achieve the regulation of the mid-infrared 3-5 micron band, the CIO grating electrode 9 structure should also reach a micron-level width. Taking the use of negative photoresist and dry etching process to prepare the CIO grating electrode 9 as an example, the CIO layer is first coated on the lower substrate 11 coated with an anti-reflection film by various coating methods, the photoresist is spin-coated on the lower substrate 11, and the mercury lamp exposure is performed using a mask designed with a corresponding pattern. After exposure, the exposed photoresist needs to be removed by etching. The developer used in the etching process is generally alkaline, and the CIO film will dissolve in the alkaline developer at a dissolution rate of tens of nanometers per second. The CIO grating electrode 9 will be corroded during the development process of the alkaline developer. Therefore, during the photolithography process, the SU-8 protective layer is spin-coated on the surface of the lower CIO electrode layer 9 of the lower substrate 11 to prevent erosion by the developer, and then the subsequent photolithography and dry etching processes are performed. During the etching process, oxygen is first used to strip off the remaining photoresist that has not reacted with the mercury lamp, then the SU-8 protective layer is etched with oxygen, and finally chlorine gas is passed into the cavity to etch out the array electrode.

[0032] The lower substrate 11 includes four sub-aperture areas which are independently controlled.

[0033] Embodiment 2: This embodiment provides a method for preparing a mid-infrared liquid crystal optical phased array based on a CIO conductive film, which comprises the following steps: Step 1, cleaning; The upper substrate 2 and the lower substrate 11 to be plated are cleaned.

[0034] In order to ensure the adhesion and flatness of the prepared film layer, the substrate to be plated needs to be cleaned before the coating process. The cleaning process mainly includes UV cleaning machine cleaning and ultrasonic cleaning machine cleaning. The coating process can only be carried out after the substrate cleaning is completed.

[0035] Step 2, coating; Depositing a mid-infrared anti-reflection film 1 on the outer surface of the upper substrate and a mid-infrared anti-reflection film 12 on the outer surface of the lower substrate on the back surfaces of the upper substrate 2 and the lower substrate 11 respectively; A mid-infrared anti-reflection film 3 on the inner surface of the upper substrate and a mid-infrared anti-reflection film 10 on the inner surface of the lower substrate are deposited on the front surfaces of the upper substrate 2 and the lower substrate 11 respectively; An upper CIO common electrode layer 4 and a lower CIO electrode layer are deposited on the mid-infrared anti-reflection film 3 on the inner surface of the upper substrate and the mid-infrared anti-reflection film 10 on the inner surface of the lower substrate, respectively.

[0036] When coating the corresponding film layer on the substrate, magnetron sputtering can be used for preparation. Magnetron sputtering uses the gas glow discharge to generate ions. The positive ions bombard the target material to be sputtered under the action of the electric field in the cavity and exchange energy with the target material atoms. The atoms or molecules on the surface of the target material obtain enough energy to escape from the surface and deposit on the substrate to form a thin film.

[0037] Step 3, photolithography; The pattern on the mask is transferred to the lower substrate 11 coated with the film layer using photoresist as a medium, and a layer of photoresist pattern having the same pattern as the mask is formed on the lower substrate 11 .

[0038] After the above film is plated, the required device pattern needs to be formed on the lower substrate 11. That is, a photolithography machine is used to transfer the pattern on the mask to the substrate plated with the film using photoresist as a medium, and finally a layer of photoresist pattern with the same mask pattern is left on the substrate.

[0039] Step 4, etching; The areas on the lower substrate 11 that are not protected by the photoresist are etched away by an etching process to obtain a CIO grating electrode; a plurality of CIO grating electrodes 9 arranged at intervals form a lower CIO electrode layer.

[0040] After the photolithography development is completed, the lower substrate 11 is a photoresist pattern with a mask pattern. At this time, an etching process is required to etch away the areas not protected by the photoresist to form an array electrode. Taking plasma etching as an example, an ion source provides charged ions, and the electric field in the reaction chamber provides energy for the plasma, so that it can bombard the material to be etched as much as possible to achieve etching of the film layer.

[0041] Step 5, preparing an alignment layer; Coating polyimide on the upper substrate 2 with the electrodes prepared, and preparing the upper liquid crystal alignment layer 5 by rubbing alignment or photo-alignment; Polyimide is coated on the lower substrate 11 with the electrodes prepared, and a lower liquid crystal alignment layer 8 is prepared by rubbing alignment or photo-alignment; The alignment directions of the upper liquid crystal alignment layer 5 on the upper substrate 2 and the lower liquid crystal alignment layer 8 on the lower substrate 11 are set to be anti-parallel.

[0042] The purpose of the orientation agent is to arrange the liquid crystal molecules in an orderly manner, making the liquid crystal molecules adjustable. The orientation agent is divided into parallel orientation agent and vertical orientation agent. The polyimide orientation agent is applied to the pre-treated substrate by spin coating, and then baked to cyclize the polyimide film to form a polymer chain, thereby improving the orderliness of the molecular structure so that the subsequent orientation can provide an anchoring effect for the liquid crystal molecules. After the orientation film is formed, the friction orientation process can be carried out. A fluff roller can be used to form grooves that have an anchoring effect on the orientation of the liquid crystal molecules, and finally an effective orientation groove is formed on the orientation film.

[0043] Step 6, pressing the box and filling the wafer; The upper substrate 2 and the lower substrate 11 are attached to each other using a sealant 14, and spacers 7 are added to the sealant 14; and then liquid crystal is poured into the area between the sealant 14, the upper substrate 21 and the lower substrate 11 using the siphon effect to form a liquid crystal layer.

[0044] After the alignment is completed, the next step is to carry out the box-forming process. The box-forming process includes applying the frame glue and pressing the box. The purpose of applying the frame glue is to use the frame glue 14 to fix the relative position of the upper substrate 2 and the lower substrate 11, and to use the spacer 7 to control the thickness of the liquid crystal layer.

[0045] When filling the crystal, siphon filling or vacuum filling is often used. Siphon filling is to use the siphon principle to suck the liquid crystal into the liquid crystal box, and is often used to fill the liquid crystal box with a small liquid crystal layer. Vacuum filling is to put the liquid crystal box into a vacuum cavity, extract the air in the liquid crystal layer, and then use a needle to drip the liquid crystal at the filling port of the liquid crystal. After the liquid crystal is degassed, slowly inflate the cavity, and use the pressure difference to fill the liquid crystal into the liquid crystal box.

[0046] The last step is to make circuit connections. According to the designed control circuit, the prepared liquid crystal phased array is connected to the control circuit using a soft strip line.

[0047] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the scope of protection of the present invention is not limited to such specific statements and embodiments. For those skilled in the art, the present invention may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A mid-infrared liquid crystal optical phased array based on CIO conductive film, characterized in that: It comprises an upper substrate assembly, a liquid crystal molecule layer (6) and a lower substrate assembly which are arranged in sequence from top to bottom; The upper substrate assembly comprises: a mid-infrared anti-reflection film (1) on the outer surface of the upper substrate, an upper substrate (2), a mid-infrared anti-reflection film (3) on the inner surface of the upper substrate, an upper CIO common electrode layer (4), and an upper orientation layer (5) arranged in sequence from top to bottom; The lower substrate assembly comprises: a lower orientation layer (8), a lower CIO electrode layer, a mid-infrared anti-reflection film (10) on the inner surface of the lower substrate, a lower substrate (11), and a mid-infrared anti-reflection film (12) on the outer surface of the lower substrate, which are arranged in sequence from top to bottom.

2. The mid-infrared liquid crystal optical phased array based on CIO conductive film according to claim 1, characterized in that: It also includes a sealant (14) located outside the liquid crystal molecule layer (6), and the upper substrate assembly and the lower substrate assembly are sealed and packaged by the sealant (14).

3. The mid-infrared liquid crystal optical phased array based on CIO conductive film and the preparation method thereof as claimed in claim 2, characterized in that: The frame glue (14) is doped with spacers (7), and the upper substrate assembly and the lower substrate assembly are supported by the spacers (7).

4. The mid-infrared liquid crystal optical phased array based on CIO conductive film according to claim 1, characterized in that: The spacer (7) is used to control the thickness of the liquid crystal molecule layer (6); the size of the spacer (7) is determined according to the birefringence difference of the liquid crystal material in the liquid crystal molecule layer (6); and the product of the birefringence difference of the liquid crystal material in the liquid crystal molecule layer (6) and the thickness of the liquid crystal molecule layer (6) is greater than the wavelength of the working electromagnetic wave used.

5. The mid-infrared liquid crystal optical phased array based on CIO conductive film according to claim 1, characterized in that: The orientation direction of the orientation film layer of the upper orientation layer (5) is opposite to the orientation direction of the orientation film layer of the lower orientation layer (8).

6. The mid-infrared liquid crystal optical phased array based on CIO conductive film according to claim 1, characterized in that: The lower CIO electrode layer comprises a plurality of CIO grating electrodes (9) arranged at intervals, each CIO grating electrode (9) is connected to a communication drive chip (13) on the lower substrate (11), and the voltage on each CIO grating electrode is independently regulated by the communication drive chip (13).

7. The mid-infrared liquid crystal optical phased array based on CIO conductive film according to claim 1, characterized in that: The voltage applied to the CIO grating electrode (9) is regulated by the communication drive chip (13), thereby changing the electric field distribution in the space where the liquid crystal molecule layer (6) is located, driving the liquid crystal molecules in the liquid crystal molecule layer (6) to rotate, and causing a phase delay change when light passes through the liquid crystal molecules.

8. The mid-infrared liquid crystal optical phased array based on CIO conductive film according to claim 1, characterized in that: The CIO grating electrode (9) is manufactured by a wet method, a dry method, magnetron sputtering or CNC engraving.

9. The mid-infrared liquid crystal optical phased array based on CIO conductive film according to claim 1, characterized in that: The lower substrate (11) comprises four sub-aperture areas that are independently controlled from each other.

10. The method for preparing a mid-infrared liquid crystal optical phased array based on a CIO conductive film according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1, cleaning; Cleaning the upper substrate (2) and the lower substrate (11) to be plated; Step 2, coating; Depositing a mid-infrared anti-reflection film (1) on the outer surface of the upper substrate and a mid-infrared anti-reflection film (12) on the outer surface of the lower substrate on the back surfaces of the upper substrate (2) and the lower substrate (11), respectively; Depositing a mid-infrared anti-reflection film (3) on the inner surface of the upper substrate and a mid-infrared anti-reflection film (10) on the inner surface of the lower substrate on the front surfaces of the upper substrate (2) and the lower substrate (11), respectively; Depositing an upper CIO common electrode layer (4) and a lower CIO electrode layer on the mid-infrared anti-reflection film (3) on the inner surface of the upper substrate and the mid-infrared anti-reflection film (10) on the inner surface of the lower substrate respectively; Step 3, photolithography; The pattern on the mask is transferred to a lower substrate (11) coated with a film layer using photoresist as a medium, and a layer of photoresist pattern having the same pattern as the mask is formed on the lower substrate (11); Step 4, etching; The areas on the lower substrate (11) that are not protected by the photoresist are etched away using an etching process to obtain a CIO grating electrode; a plurality of CIO grating electrodes (9) arranged at intervals form a lower CIO electrode layer; Step 5, preparing an alignment layer; Coating polyimide on the upper substrate (2) on which the electrodes have been prepared, and preparing an upper liquid crystal alignment layer (5) by means of rubbing alignment or photo-alignment; Coating polyimide on the lower substrate (11) on which the electrode has been prepared, and preparing a lower liquid crystal alignment layer (8) by means of rubbing alignment or photo-alignment; The alignment directions of the upper liquid crystal alignment layer (5) on the upper substrate (2) and the lower liquid crystal alignment layer (8) on the lower substrate (11) are set to be anti-parallel; Step 6, pressing the box and filling the wafer; The upper substrate (2) and the lower substrate (11) are bonded together using a frame glue (14), and a spacer (7) is added to the frame glue (14); and then liquid crystal is injected into the area between the frame glue (14), the upper substrate (21), and the lower substrate (11) using the siphon effect to form a liquid crystal layer.

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