CN114578586A

CN114578586A - Light beam control device

Info

Publication number: CN114578586A
Application number: CN202210202850.4A
Authority: CN
Inventors: 祁聪; 胡志浩
Original assignee: Shanghai Dageling Technology Co ltd
Current assignee: Shanghai Dageling Technology Co ltd
Priority date: 2022-03-03
Filing date: 2022-03-03
Publication date: 2022-06-03

Abstract

An optical beam steering apparatus, comprising: a substrate and a mirror layer, a conductive layer, a dielectric layer, and a sub-wavelength antenna unit stacked on the substrate, wherein the sub-wavelength antenna unit and the mirror layer are configured to apply different voltages; the first bonding layer is arranged between the dielectric layer and the sub-wavelength antenna unit, the light beam control device can realize tight connection between the dielectric layer and the sub-wavelength antenna unit, and can ensure that the deflection angle of refracted light and reflected light can be conveniently controlled.

Description

Light beam control device

Technical Field

Embodiments of the present disclosure relate to a light beam control apparatus.

Background

The super-surface can be classified into an optical super-surface, an acoustic super-surface, a mechanical super-surface, and the like according to the type of the modulated wave. Optical super-surfaces are the most common type, which can control the polarization, phase, amplitude and frequency characteristics of electromagnetic waves by sub-wavelength microstructures, and super-surface technology is an emerging technology combining optics and nanotechnology.

Supersurfaces can be considered as two-dimensional metamaterials because they are characterized by a repeating pattern of sub-wavelength structures and they have many of the same advantages as metamaterials, which are even more advantageous than metamaterials in many respects. For example, a meta-surface may transmit light more efficiently than a meta-material. In the aspect of polarization, the super surface can realize functions of polarization conversion, optical rotation, vector beam generation and the like. In the aspect of amplitude regulation, the super surface can realize asymmetric transmission, antireflection, transmission increase, a magnetic mirror and the like of light. In the aspect of regulating and controlling frequency, the microstructure of the super surface can realize stronger local field enhancement under the condition of resonance, and the enhancement of nonlinear signals or fluorescence signals can be realized by utilizing the local field enhancement effects. In the visible light band, light of different frequencies corresponds to different colors, and the frequency selective characteristics of the super-surface can be used to realize structural colors. The super surface can be utilized to realize free regulation and control of the color of the super surface by changing the geometric parameters such as the size, the shape and the like of the structural unit of the super surface, so that the super surface can be used in the fields of high-pixel imaging, visual biosensing and the like.

Disclosure of Invention

At least one embodiment of the present disclosure provides a light beam control apparatus that achieves tighter connection between a dielectric layer and a subwavelength antenna unit by providing a first adhesive layer between the dielectric layer and the subwavelength antenna unit, thereby ensuring structural stability of the entire light beam control unit.

At least one embodiment of the present disclosure provides a light beam control device, including: a substrate and a mirror layer, a conductive layer, a dielectric layer, and a sub-wavelength antenna unit stacked on the substrate, wherein the sub-wavelength antenna unit and the mirror layer are configured to apply different voltages; a first adhesive layer is disposed between the dielectric layer and the sub-wavelength antenna element.

For example, in the beam control device provided in at least one embodiment of the present disclosure, a chemical bond is formed between the first adhesive layer and the dielectric layer and between the first adhesive layer and the sub-wavelength antenna unit, and the first adhesive layer is configured to adhere the dielectric layer and the sub-wavelength antenna unit.

For example, in the light beam control device provided in at least one embodiment of the present disclosure, the thickness of the first bonding layer is 1 nm to 50 nm, and the material of the first bonding layer includes at least one of a simple titanium metal, a simple chromium metal, a simple tungsten metal, and a simple niobium metal.

For example, in a beam control device provided in at least one embodiment of the present disclosure, the first adhesive layer has conductivity, and an orthogonal projection of the first adhesive layer on the substrate and an orthogonal projection of the sub-wavelength antenna unit on the substrate at least partially overlap.

For example, in a beam control device provided in at least one embodiment of the present disclosure, the first adhesive layer has an insulating property, and an orthogonal projection of the sub-wavelength antenna unit on the substrate is located within an orthogonal projection of the first adhesive layer on the substrate.

For example, in a light beam control device provided in at least one embodiment of the present disclosure, a second adhesive layer is provided between the substrate and the mirror layer, the second adhesive layer being configured to bond the substrate and the mirror layer.

For example, in the light beam control device provided in at least one embodiment of the present disclosure, a chemical bond is formed between the second adhesive layer and the substrate, and between the second adhesive layer and the mirror layer, so as to bond the substrate and the mirror layer.

For example, in the light beam control device provided in at least one embodiment of the present disclosure, the thickness of the second bonding layer is 1 nm to 1000 nm, and the material of the second bonding layer includes at least one of a simple substance of titanium metal, a simple substance of chromium metal, a simple substance of tungsten metal, and a simple substance of niobium metal.

For example, in a light beam control device provided in at least one embodiment of the present disclosure, a material of the first adhesive layer and a material of the second adhesive layer are the same or different.

For example, in a beam control device provided in at least one embodiment of the present disclosure, the sub-wavelength antenna unit includes a plurality of antennas, and each of the antennas is shaped like a rod.

For example, in a beam control apparatus provided in at least one embodiment of the present disclosure, at least two adjacent antennas are configured to form different voltage differences with the mirror layer.

For example, in a beam control device provided in at least one embodiment of the present disclosure, the sub-wavelength antenna unit includes a plurality of antennas, and the plurality of antennas are arranged in an array.

For example, in a beam control apparatus provided in at least one embodiment of the present disclosure, at least two adjacent antennas in the column direction are configured to form different voltage differences with the mirror layer, and/or at least two adjacent antennas in the row direction are configured to form different voltage differences with the mirror layer.

For example, in a beam control device provided in at least one embodiment of the present disclosure, the sub-wavelength antenna unit includes a plurality of annular antennas, and the plurality of antennas are arranged in concentric circles.

For example, in the light beam control device provided in at least one embodiment of the present disclosure, the light beam control device further includes at least two power lines, the plurality of antennas and the power lines are respectively electrically connected through a connection portion, each of the power lines is electrically connected to one or more of the antennas, and the power lines are configured to apply a voltage to the corresponding antenna.

For example, in a beam control device provided in at least one embodiment of the present disclosure, an insulating layer is provided between the subwavelength antenna unit and the power supply line, and the connection portion is provided in a via structure that penetrates the power supply line and the insulating layer.

For example, in a beam control device provided in at least one embodiment of the present disclosure, a material of the sub-wavelength antenna unit includes at least one of a conductive metal, a conductive metal oxide, and conductive graphene.

For example, in a light beam control device provided in at least one embodiment of the present disclosure, a material of the mirror layer includes at least one of a metal having reflectivity and conductivity, a conductive metal oxide, and conductive graphene.

For example, in a light beam control device provided in at least one embodiment of the present disclosure, a material of the conductive layer includes indium tin oxide, indium zinc oxide, or indium gallium zinc oxide.

For example, in a beam control device provided in at least one embodiment of the present disclosure, a material of the dielectric layer includes an inorganic insulating material or an organic insulating material.

Drawings

To more clearly illustrate the technical solutions of the embodiments of the present disclosure, the drawings of the embodiments will be briefly introduced below, and it is apparent that the drawings in the following description relate only to some embodiments of the present disclosure and are not limiting to the present disclosure.

Fig. 1 is a schematic cross-sectional structure diagram of a light beam control device according to at least one embodiment of the present disclosure;

fig. 2 is a schematic perspective structural view of a light beam control apparatus according to at least one embodiment of the present disclosure;

fig. 3 is a schematic plan view of a sub-wavelength antenna unit according to at least one embodiment of the present disclosure;

FIG. 4 is a graph illustrating phase changes of reflected light with changes in electron concentration according to at least one embodiment of the present disclosure;

fig. 5 is a schematic plan view of another sub-wavelength antenna unit according to at least one embodiment of the present disclosure;

fig. 6 is a schematic plan view of another sub-wavelength antenna unit according to at least one embodiment of the present disclosure;

fig. 7 is a schematic plan view of another sub-wavelength antenna unit according to at least one embodiment of the present disclosure;

fig. 8 is a schematic plan view illustrating a structure of a sub-wavelength antenna unit and a connection portion according to at least one embodiment of the present disclosure; and

fig. 9 is a schematic perspective view of a sub-wavelength antenna unit and a connection portion according to at least one embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present disclosure more apparent, the technical solutions of the embodiments of the present disclosure will be described clearly and completely with reference to the drawings of the embodiments of the present disclosure. It is to be understood that the described embodiments are only a few embodiments of the present disclosure, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the described embodiments of the disclosure without any inventive step, are within the scope of protection of the disclosure.

Unless otherwise defined, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather is used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

For the condition that the incident light is infrared light, near-infrared light or visible light, the control voltage can change the electron concentration in the conducting layer to realize the change of the phase, and further can realize the control of the phase surface of the light reflected or transmitted from the surface of the light beam control device. Taking the example of light reflected from the surface of the light beam control device, the structure of the light beam control device mainly includes a mirror layer, a conductive layer, a dielectric layer, a sub-wavelength antenna unit, and a power supply for establishing a voltage between the sub-wavelength antenna unit and the mirror layer, so as to achieve the purpose of controlling the direction of the light beam. However, the inventors of the present disclosure have found that, when another layer structure is formed on the surface of a certain substrate material, due to the difference in chemical properties of the materials of the two layer structures in contact with each other, the bonding force between the two layer structures in contact with each other may be not strong enough, so that the quality of the later-formed layer structure is not good or a delamination phenomenon between the two layer structures in contact with each other is easily caused, or a phenomenon in which the later-formed layer structure is easily peeled off from the earlier-formed layer structure, that is, there is a problem in that the connection between the dielectric layer and the sub-wavelength antenna unit in the current beam control device is unstable, so that the manipulation of the phase plane of light is unstable.

The inventors of the present disclosure have noted that an adhesion layer may be formed on a previously formed layer structure (e.g., a dielectric layer) first, and the material of the adhesion layer is generally selected to have a strong bonding force with both the previously formed layer structure (e.g., the dielectric layer) and a subsequently formed layer structure (e.g., a sub-wavelength antenna unit). Specifically, the principle of increasing the bonding force between layer structures mainly includes: increasing the wettability (wetting) of the subsequently formed layer structure, so that stronger chemical bonds are formed between the subsequently formed layer structure and the previously formed layer structure, so that the connection between the layer structures which are in contact with one another is tighter. For example, an adhesion layer is formed between the dielectric layer and the interface of the sub-wavelength antenna unit in the optical beam control device, and the material of the adhesion layer includes a simple metal such as chromium, tungsten, niobium, chromium, or titanium.

At least one embodiment of the present disclosure provides a light beam control device, including: the light beam control device comprises a substrate, and a mirror layer, a conductive layer, a dielectric layer and a sub-wavelength antenna unit which are arranged on the substrate in a laminating way, wherein the sub-wavelength antenna unit and the mirror layer are configured to apply different voltages, a first bonding layer is arranged between the dielectric layer and the sub-wavelength antenna unit, and the light beam control device can realize that the connection between the dielectric layer and the sub-wavelength antenna unit is tighter through the first bonding layer arranged between the dielectric layer and the sub-wavelength antenna unit, so that the stability of the structure of the whole light beam control unit can be ensured.

For example, fig. 1 is a schematic cross-sectional structure diagram of a light beam control device according to at least one embodiment of the present disclosure, and as shown in fig. 1, the light beam control device 100 includes: the antenna includes a substrate 101, a mirror layer 102, a conductive layer 103, a dielectric layer 104, and a sub-wavelength antenna unit 105 stacked on the substrate 101, the sub-wavelength antenna unit 105 and the mirror layer 102 being configured to apply different voltages so that a voltage difference is provided between the sub-wavelength antenna unit 105 and the mirror layer 102, and a first adhesive layer 106 is provided between the dielectric layer 104 and the sub-wavelength antenna unit 105. The whole structure of the beam control apparatus 100 is a super-surface structure, and the conductive layer 103 in the beam control apparatus can make the vicinity of the interface between the electron-conductive layer 103 and the dielectric layer 104 (i.e. the effective area a) in the conductive layer 103 gather due to the change of the voltage applied thereto, causing the electron concentration in the effective area a of the conductive layer 103 to change, so that the real part of the dielectric constant of the effective area a is close to 0, furthermore, the phase plane of the light reflected or transmitted from the surface of the light beam control device can be manipulated, and it should be noted that only the effective area a is roughly shown by a dotted rectangle in fig. 1, but does not mean that the effective area a is limited to only this area, and may include areas near this area, i.e. may be a larger area than the rectangular dashed box shown in fig. 1, or a smaller area than the rectangular dashed box shown in fig. 1.

For example, when the first adhesive layer 106 is not formed between the sub-wavelength antenna unit 105 and the dielectric layer 104, the formation process of the dielectric layer 104 and the sub-wavelength antenna unit 105 includes: the material of the sub-wavelength antenna element 105 (e.g. gold) is directly evaporated to the surface of the dielectric layer 104 (silicon dioxide) using electron beam: instead of forming a continuous gold film layer, gold nanoparticles are formed on the surface of the dielectric layer 104 at the beginning. As the electron beam evaporation continues, the gold film layer on the surface of the dielectric layer 104 becomes continuous, but due to the coalescence of different crystal grains, the formed gold film layer has a certain degree of surface roughness, so that the quality of the finally formed gold film layer is poor.

For example, taking the example that the material of the first adhesive layer 106 is titanium simple substance, the material of the sub-wavelength antenna unit 105 is gold, and the material of the dielectric layer 104 is silicon dioxide, when the first adhesive layer 106 is disposed between the sub-wavelength antenna unit 105 and the mirror layer 102, the forming processes of the dielectric layer 104, the first adhesive layer 106, and the sub-wavelength antenna unit 105 include: a simple substance of titanium is deposited on the dielectric layer 104, and a chemical bond is formed between the simple substance of titanium and an oxygen atom on the surface of the dielectric layer 104 formed of a silicon dioxide material, so that the purpose of good combination of the simple substance of titanium and silicon dioxide is achieved. The addition of the titanium metal simple substance has great influence on the grain size and grain orientation of the film formed by the gold material, and meanwhile, the first bonding layer 106 can play a role in wetting the sub-wavelength antenna unit 105 formed subsequently, compared with the example that pure Au is directly evaporated on the surface of silicon dioxide, the nucleation energy barrier is reduced, the number of nucleation sites is increased, and the wettability is enhanced due to the formation of Ti-Au chemical bonds, so that Au grains are more compact and easier to nucleate, and meanwhile, the mutual diffusion among Au atoms can be promoted, and the flat and continuous gold film layer can be formed more favorably.

For example, fig. 2 is a schematic diagram of a perspective structure of a light beam control device according to at least one embodiment of the present disclosure, and as shown in fig. 2, the perspective structure of the light beam control device 100 provides a schematic diagram of a super-surface implementation of reflection light control, and the purpose of manipulating the phase of the reflected light is achieved by establishing different voltage differences between the sub-wavelength antenna unit 105 and the mirror layer 102, so as to implement "anomalous" reflection. For example, as shown in fig. 2, the incident light is incident perpendicularly to the surface of the structure of the optical beam control device 100, i.e., incident along the z direction, but the reflected light is not emitted perpendicularly to the surface of the structure of the optical beam control device 100, but has a deflection with a certain angle on the plane perpendicular to the main surface of the optical beam control device 100 (i.e., on the plane where the x axis and the z axis are located), and the deflection angle can be controlled by the super-surface structure and the voltage difference between the sub-wavelength antenna unit 105 and the mirror layer 102.

For example, in conjunction with fig. 1 and 2, the concentration of electrons in the conductive layer 103 can be varied by adjusting the voltage difference between the sub-wavelength antenna element 105 and the mirror layer 102. For example, in one example, the material of the sub-wavelength antenna elements 105 and the mirror layer 102 are both Au, while the conductive layer 103 is formed of indium tin oxide having a thickness of about 30nm, and the dielectric layer 104 is formed of aluminum oxide, assuming an electron concentration of indium tin oxide of 6x10²⁰cm^-3Then in the sub-wavelength antenna unit 105And the mirror layer 102, the electron concentration of the active area a of the indium tin oxide may be increased, and the higher the voltage, the more the electron concentration is increased, and the closer the electron concentration to the interface portion of the conductive layer 103 and the dielectric layer 104 is, the more the electron concentration is decreased with increasing distance from the interface of the conductive layer 103 and the dielectric layer 104. In this way, the electron concentration of the effective area in the conductive layer 103 can be regulated by a change in the voltage formed between the sub-wavelength antenna element 105 and the mirror layer 102.

For example, as shown in fig. 2, the sub-wavelength antenna unit 105 includes a plurality of antennas 1051, the plurality of antennas 1051 are sequentially arranged, the plurality of antennas 1051 are arranged at equal intervals, or adjacent antennas 1051 are spaced at different intervals, which is not limited in the embodiments of the present disclosure. In fig. 2, the sub-wavelength antenna unit 105 includes 9 antennas 1051 as an example for explanation, the voltage difference formed between each antenna 1051 and the mirror layer 102 may be different, or three antennas 1051 that are sequentially and adjacently disposed may be a group, different voltage differences formed between the three antennas 1051 in the group and the mirror layer 102 respectively may also be used, and the three antennas 1051 that are sequentially and adjacently disposed may also be used as a repeating unit for repeating, or two adjacent antennas 1051 may also be used as a repeating unit, or four antennas 1051, five antennas 1051, six antennas 1051, seven antennas, and the like that are sequentially disposed may also be used as a repeating unit.

For example, as shown in fig. 2, in one example (referred to as example 1), voltage differences formed between the first antenna 1051, the second antenna 1051, the third antenna 1051 and the mirror layer 102 are V1, V2 and V3 in sequence, and V1, V2 and V3 are all different and serve as a repeating unit. Similarly, the voltage differences between the fourth antenna 1051, the fifth antenna 1051, and the sixth antenna 1051 and the mirror layer 102 are V4 ═ V1, V5 ═ V2, and V6 ═ V3 in this order; the voltage differences formed between the seventh antenna 1051, the eighth antenna 1051, the ninth antenna 1051 and the mirror layer 102 are V7-V1, V8-V2 and V9-V3 in sequence, so that the voltage differences formed between any two adjacent antennas 1051 and the mirror layer 102 are different, the voltage differences change periodically by three antennas, the electron concentration at the interface part of the conductive layer 103 and the dielectric layer 104 also changes periodically, and the phase of the light emitted from the super-surface is changed periodically. The rate of change of this periodic phase change in the x-axis direction, Φ/dx, determines the "anomalous" deflection angle of the light exiting the super-surface.

Similarly, for an example that two antennas 1051, four antennas 1051, five antennas 1051, six antennas 1051, seven antennas 1051, or eight antennas 1051, etc. arranged in sequence are used as one repeating unit, reference may be made to the above description based on three antennas 1051 as one repeating unit, and details are not repeated here.

For example, in another example (example 2), as shown in fig. 2 as well, the first antenna 1051, the second antenna 1051, and the third antenna 1051 form a group, and the voltage differences formed between the first antenna 1051, the second antenna 1051, and the third antenna 1051 and the mirror layer 102 are the same and are all V1. The fourth antenna 1051, the fifth antenna 1051 and the sixth antenna 1051 form a group, and the voltage differences formed between the fourth antenna 1051, the fifth antenna 1051 and the sixth antenna 1051 and the mirror layer 102 are the same and are all V2; the seventh antenna 1051, the eighth antenna 1051, and the ninth antenna 1051 form a set, and the voltage differences between the seventh antenna 1051, the eighth antenna 1051, and the ninth antenna 1051 and the mirror layer 102 are equal and are all V3. The voltage difference between the first antenna and the ninth antenna and the mirror layer 102 is sequentially repeated from the tenth antenna to the eighteenth antenna, and the voltage difference formed between the antenna 1051 and the mirror layer 102 is periodically changed by the nine antennas, so that the electron concentration at the interface part of the conductive layer 103 and the dielectric layer 104 is also periodically changed, and the phase of the light emitted from the super-surface is periodically changed. Assuming that the structure, material, and incidence conditions of example 2 are the same as those of example 1 except for the above-mentioned voltage application manner, and V1, V2, and V3 in example 2 are the same as those of V1, V2, and V3 in example 1, the rate of change d Φ/dx of the periodic phase change in the x-axis direction of example 2 is one third of the rate of change d Φ/dx of the periodic phase change in the x-axis direction of example 1, and the "abnormal" deflection angle is also different from that in example 1.

Similarly, two antennas 1051, four antennas 1051, five antennas 1051, six antennas 1051, seven antennas 1051, or eight antennas 1051, etc., which are sequentially arranged, are taken as one combination, and in each combination, an example in which the voltage difference formed between each antenna 1051 and the mirror layer 102 is the same can be referred to the above-described description about three antennas 1051 as one combination. That is, when two antennas 1051 are combined, the voltage differences formed between the antennas 1051 and the mirror layer 102 arranged in sequence are respectively V1, V1, V2, V2, V3, V3, V4, V4, and the like; when four antennas 1051 are combined, the voltage differences formed between the antennas 1051 and the mirror layer 102 which are sequentially arranged are respectively V1, V1, V1, V1, V2, V2, V2, V2, V3, V3, V3, V3, V4, V4, V4, V4, and the like, which is not limited in the embodiments of the present disclosure.

For example, as shown in fig. 1, in the light beam control apparatus 100, the material of the first bonding layer 106 includes a simple titanium metal, a simple chromium metal, a simple tungsten metal, a simple niobium metal, and the like, and chemical bonds are formed between the first bonding layer 106 and the dielectric layer 104, and between the first bonding layer 106 and the sub-wavelength antenna unit 105. For example, a simple titanium metal, a simple chromium metal, a simple tungsten metal, or a simple niobium metal may be deposited on the dielectric layer 104 by an evaporation coating method, so that the first bonding layer 106 is formed on the dielectric layer 104, that is, a material of the first bonding layer 106 includes at least one of a simple titanium metal, a simple chromium metal, a simple tungsten metal, and a simple niobium metal, and the first bonding layer 106 is configured to bond the dielectric layer 104 and the sub-wavelength antenna unit 105.

For example, since the size of the entire light beam control device 100 is set to be small, the thickness of the first adhesive layer 106 is set to be thin, for example, 1 to 50 nm. The first adhesive layer 106 may have conductivity or insulation, and the embodiment of the present disclosure is not limited thereto. Note that the thickness of the first adhesive layer 106 is too thin, and the thickness of the first adhesive layer 106 shown in fig. 2 is thickened.

The first adhesive layer 106 may be formed of other materials, for example, an adhesive paste formed of an organic material, as long as the thickness of the formed first adhesive layer 106 is 1 to 50 nm, which is not limited in the embodiment of the present disclosure.

For example, in one example, the first adhesive layer 106 has conductivity, and an orthographic projection of the first adhesive layer 106 on the substrate 101 and an orthographic projection of the sub-wavelength antenna unit 105 on the substrate 101 at least partially overlap. The "at least partially overlapping" includes that a part of the orthographic projection of the first adhesive layer 106 on the substrate 101 overlaps with a part of the orthographic projection of the subwavelength antenna unit 105 on the substrate 101; alternatively, the orthographic projection of part of the first adhesive layer 106 on the substrate 101 and the orthographic projection of all the sub-wavelength antenna units 105 on the substrate 101 overlap; alternatively, the orthographic projection of all the first adhesive layers 106 on the substrate 101 and the orthographic projection of part of the sub-wavelength antenna units 105 on the substrate 101 overlap, which is not limited in the embodiment of the disclosure.

For example, in one example, the orthographic projection of the first adhesive layer 106 on the substrate 101 and the orthographic projection of the sub-wavelength antenna unit 105 on the substrate 101 are completely overlapped, so that the sub-wavelength antenna unit 105 is completely attached to the dielectric layer 104 through the first adhesive layer 106, and thus the sub-wavelength antenna unit 105 is tightly connected to the dielectric layer 104, and the first adhesive layer 106 does not occupy more space.

For example, in one example, the first adhesive layer 106 is conductive and is formed on the whole surface, the sub-wavelength antenna unit 105 includes a plurality of antennas 1051 disposed at intervals, and the plurality of antennas 1051 can be formed by a patterning process, that is, the first adhesive layer 106 and the sub-wavelength antenna unit 105 are formed in different process steps, so that the orthographic projection of the plurality of antennas 1051 on the substrate 101 is completely located within the orthographic projection of the first adhesive layer 106 on the substrate 101.

For example, the plurality of antennas 1051 included in the sub-wavelength antenna unit 105 and spaced apart from each other may be formed by a patterning process. When the orthographic projection of the first adhesive layer 106 on the substrate 101 and the orthographic projection of the sub-wavelength antenna unit 105 on the substrate 101 are completely overlapped, the first adhesive layer 106 and the plurality of antennas 1051 can be formed through the same patterning process, thereby saving process steps.

It should be noted that the "patterning process" refers to forming a material of the entire layer of the sub-wavelength antenna unit 105, then forming a photoresist on the material of the entire layer of the sub-wavelength antenna unit 105, then irradiating the photoresist with ultraviolet rays using a mask plate to pattern the photoresist, then patterning the material of the sub-wavelength antenna unit 105 using the photoresist as a mask, and removing the photoresist remaining on the formed plurality of antennas 1051.

It should also be noted that other layer structures may also be formed by using a patterning process, where the patterning process includes applying a material of a film layer to be patterned on a base film layer, then forming a photoresist layer on the film layer to be patterned, irradiating the photoresist with ultraviolet light using a mask plate to pattern the photoresist, then patterning the film layer to be patterned with the photoresist as a mask, and removing the residual photoresist to form a final layer structure.

For example, in one example, the first adhesive layer 106 has insulation, and the orthogonal projection of the sub-wavelength antenna unit 105 on the substrate 101 is located within the orthogonal projection of the first adhesive layer 106 on the substrate 101. That is, the area covered by the first adhesive layer 106 may extend to the outside of the area covered by the sub-wavelength antenna unit 105, and the area of the first adhesive layer 106 is larger than the area covered by the sub-wavelength antenna unit 105, which may reduce the complexity of the manufacturing process, thereby reducing the process difficulty.

For example, as shown in fig. 1, a second adhesive layer 107 is provided between the substrate 101 and the mirror layer 102, and the second adhesive layer 107 is arranged to adhere the substrate 101 and the mirror layer 102. The orthographic projection of the second adhesive layer 107 on the substrate 101 and the orthographic projection of the mirror layer 102 on the substrate 101 at least partially overlap, and in one example, the orthographic projection of the second adhesive layer 107 on the substrate 101 and the orthographic projection of the mirror layer 102 on the substrate 101 coincide, i.e., the second adhesive layer 107 fully adheres the mirror layer 102 to the substrate 101, so that the mirror layer 102 and the substrate 101 are tightly connected.

For example, in one example, chemical bonds are formed between the second bonding layer 107 and the substrate 101 and between the second bonding layer 107 and the mirror layer 102, for example, titanium metal, chromium metal, tungsten metal or niobium metal may be deposited on the dielectric layer 104 by evaporation plating, so as to bond the substrate 101 and the mirror layer 102, so that the connection between the substrate 101 and the mirror layer 102 is tighter.

For example, in one example, the thickness of the second bonding layer 107 is 1 nm to 1000 nm, and the material of the second bonding layer 107 includes at least one of a simple metal of titanium, a simple metal of chromium, a simple metal of tungsten, and a simple metal of niobium.

Since the size of the entire light beam control apparatus 100 is set small, the thickness of the second adhesive layer 107 is set thin, for example, the thickness of the second adhesive layer 107 is 1 nm to 1000 nm. The second adhesive layer 107 may have conductivity or insulation, and the embodiment of the present disclosure is not limited thereto.

The second adhesive layer 107 may be formed of other materials, for example, adhesive glue formed of organic materials, as long as the thickness of the formed second adhesive layer 107 is 1 to 1000 nm, which is not limited in the embodiments of the present disclosure.

For example, in one example, the material of the first bonding layer 106 is the same as the material of the second bonding layer 107, such that the first bonding layer 106 and the second bonding layer 107 can be formed using the same process equipment and the same material, thereby simplifying the process of preparing the first bonding layer 106 and the second bonding layer 107 and reducing the equipment cost and the production cost.

For example, in another example, the material of the first adhesive layer 106 and the material of the second adhesive layer 107 may be different, so that the variety of materials used can be made more abundant.

For example, fig. 3 is a schematic plan view illustrating a structure of a sub-wavelength antenna unit according to at least one embodiment of the present disclosure, as shown in fig. 3, each antenna 1051 is shaped like a rod, and a connection terminal is disposed at one end of each antenna 1051, and the connection terminals are respectively connected to an external power source. In fig. 3, 100 antennas 1051 are shown, and the voltage difference formed between each antenna 1051 and the mirror layer 102 is V1, V2, V3, V4 … V99, and V100 in this order. Here, V1-V100 has at least two different values, and the setting of the voltage difference has periodicity. Periodicity refers to two aspects: on one hand, 1-N adjacent antennas are used as a group, and the voltage difference between the same group of antennas and the mirror layer is the same; a second aspect is that the voltage difference for different sets of antennas and mirror layers has a plurality (e.g., 2-N) of different values, and that these different values of voltage difference should occur repeatedly and periodically. For example, with 2 adjacent antennas as a group, there are 3 different voltage differences between the different groups of antennas and the mirror layer: va, Vb, Vc, and appears repeatedly. The voltage difference between the 100 antennas and the mirror layer can be set as follows: v1 ═ Va, V2 ═ Va, V3 ═ Vb, V4 ═ Vb, V5 ═ Vc, V6 ═ Vc, V7 ═ Va, V8 ═ Va, V9 ═ Vb, V10 ═ Vb, V11 ═ Vc, V12 ═ Vc …. The total number of the periodic antennas 1051 may also be more, and the embodiment of the disclosure is not limited thereto. The periodic setting of the voltage difference between the antenna 1051 and the mirror layer 102 may further include grouping 3-N adjacent antennas, and the voltage difference between the antennas of different groups and the mirror layer may have 2-N different values, or may be more, and this is not limited by the embodiment of the disclosure.

For example, in one example, at least two antennas 1051 are configured to form different voltage differences with the mirror layer 102, since the applied voltage can make the conductive layer 103 gather near the interface between the conductive layer 103 and the dielectric layer 104 (called the effective area a), so that the real part of the dielectric constant of the effective area a is close to zero, and the difference of the voltage differences causes the electron concentration of the effective area a to be different, the phase and amplitude of the light reflected or transmitted by the super surface are modulated by controlling the change of the electron concentration of the effective area a, so as to realize "abnormal" reflection or transmission.

For example, if the real part of the permittivity of the effective area a of the conductive layer 103 is close to zero, the electric field component Ez in the direction perpendicular to the conductive layer 103 in the effective area of the conductive layer can be greatly enhanced according to the boundary condition of continuity of the electric displacement at the boundary of the two materials. The coupling of the resonance of the region where the dielectric constant of indium tin oxide goes to zero and the plasmon resonance of the super-surface allows the super-surface structure the ability to voltage tune the phase and amplitude of incident light of a particular wavelength.

If phase and amplitude voltage modulation for a specific wavelength is to be achieved, it is not only necessary that the sub-surface have a specific geometry, e.g. thickness of the individual layers, shape, width, height and period of the arrangement of the antenna, but also that the dielectric constant of the conductive layer can be modulated by the voltage. For example, for a super surface of a conductive layer formed by indium tin oxide, a voltage may be used to adjust an electron concentration of an effective region in indium tin oxide, and according to Drude model, a change in the electron concentration in indium tin oxide may cause a change in a dielectric constant of indium tin oxide, and further cause a different change in a phase of refracted light and a phase of reflected light, for example, fig. 4 is a graph showing a phase change of reflected light with a change in the electron concentration according to at least one embodiment of the present disclosure, and as shown in fig. 4, the electron concentration in the effective region in the conductive layer under all antennas is changed from 2.5x10²⁰cm^-3To 2x10²¹cm^-3The phase change of the reflected light received at a position above the super-surface structure may be up to about 600 deg..

For example, fig. 5 is a schematic plan view of another sub-wavelength antenna unit according to at least one embodiment of the present disclosure, as shown in fig. 5, each antenna is a group, and there are 7 different voltage differences between different groups of antennas and the mirror layer: v1, V2, V3, V4, V5, V6 and V7, and occur periodically, the total number of antennas is not limited. Given that the super-surface structure is used for manipulation of the transmission angle of transmitted light, the interpretation of the "anomalous" refraction of the light refracted by the super-surface is based on the generalized Snell's law, n₂sinβ₂-n₁sinβ₁＝(λ₀/2 π) dφ/dx, where n₁Refractive index of the first medium layer through which incident light passes, n₂Refractive index of the second medium layer, beta, for refracting light through₁Angle of incidence of incident light, beta₂For refracting the refraction angle of the light ray, the phi/dx represents the extra phase in the antenna array period direction caused by the sub-wavelength elements on the super-surface after the incident light ray is incident on the super-surfaceA variable rate of change.

Assuming that the super-surface structure is used for the manipulation of the reflection angle of the reflected light, the periodic manner of setting the voltage difference is still shown in fig. 5, taking each antenna as a group, and there are 7 different voltage differences between the different groups of antennas and the mirror layer: v1, V2, V3, V4, V5, V6, and V7, and occur periodically, and the total number of antennas is not limited. The interpretation of the "anomalous" reflection of the reflected light by a super-surface according to the generalized Snell's law is also analogous: sin beta₃-sinβ₁＝(λ₀/2πn₁) d phi/dx, wherein beta₃Is the angle of reflection of the reflected light. If the wavelength lambda of the incident light₀Is 1400nm, n₁The incident angle of the light is 0 degrees, and the period of the antenna along the x-axis direction is 400nm each. By setting the voltage difference between each antenna and the mirror layer, for example, the voltage differences formed between the first antenna 1051, the second antenna 1051, the third antenna 1051, the fourth antenna 1051, the fifth antenna 1051, the sixth antenna 1051, and the seventh antenna 1051 and the mirror layer 102 are V1, V2, V3, V4, V5, V6, and V7 in this order, in the case of more antennas 1051, the voltage differences are applied in turn with the period of V1-V7, so that the electron concentration in the effective area in the conductive layer under each antenna changes periodically, and the reflected light near each antenna changes periodically: 0, 2 pi/7, 4 pi/7, 6 pi/7, 8 pi/7, 10 pi/7, 12 pi/7, 0, 2 pi/7, 4 pi/7, 6 pi/7, …. It can be calculated that d phi/dx equals pi/1400 nm^-1Then the reflection angle beta can be obtained according to the above formula₃Approximately equal to 30 degrees, therefore, the super-surface realizes the 'abnormal' reflection for the vertically incident light, namely the reflection angle is 30 degrees instead of 0 degree, namely the phase change period can be controlled by setting a proper voltage difference (including the magnitude of the voltage difference and the period of the voltage difference change), and then the emergent angle of the reflected light can be controlled, and the 'abnormal' reflection of the reflected light is realized.

For example, in another example, if the wavelength λ of the incident light is₀Is 1400nm, n₂The incident angle of the light is 0 degrees, and the period of the antenna along the x-axis direction is 400nm each. By arranging each antenna and mirrorThe voltage differences between the surface layers, for example, the voltage differences between the first antenna 1051, the second antenna 1051, the third antenna 1051, the fourth antenna 1051, the fifth antenna 1051, the sixth antenna 1051, the seventh antenna 1051, the eighth antenna 1051, the ninth antenna 1051, the tenth antenna 1051, the eleventh antenna 1051, the twelfth antenna 1051, the thirteenth antenna 1051, and the fourteenth antenna 1051, respectively, and the mirror layer 102 are V1, V1, V2, V2, V3, V3, V4, V4, V5, V5, V6, V6, V7, and V7 in turn, so that the concentration of electrons in the effective area in the conductive layer under each antenna periodically changes, and thus the phase change occurs in the vicinity of each antenna: 0, 0, 2 pi/7, 4 pi/7, 6 pi/7, 8 pi/7, 10 pi/7, 12 pi/7, …, it can be calculated that d phi/dx is equal to pi/2800 nm^-1Then the reflection angle beta can be obtained according to the above formula₃Equal to 14.5 degrees, so that the super-surface realizes "abnormal" reflection for the vertically incident light, i.e. the reflection angle is equal to about 14.5 degrees instead of 0 degrees, i.e. the phase change period can be controlled by setting a suitable voltage difference (including the magnitude of the voltage difference and the period of the voltage difference change), and the exit angle of the reflected light can be controlled, thereby realizing "abnormal" reflection of the reflected light.

For example, fig. 6 is a schematic plan view of another sub-wavelength antenna unit according to at least one embodiment of the present disclosure, and as shown in fig. 6, the sub-wavelength antenna unit 105 includes a plurality of antennas 1051, and the antennas 1051 are arranged in an array. For example, the plurality of antennas 1051 are arranged in a matrix, and the planar shape of each antenna 1051 is a rectangle, a square, a circle, or the like.

As shown in fig. 6, at least two adjacent antennas 1051 in the column direction are arranged to form different voltage differences with the mirror layer 102, or at least two adjacent antennas 1051 in the row direction are arranged to form different voltage differences with the mirror layer 102, or at least two adjacent antennas 1051 in the column direction are arranged to form different voltage differences with the mirror layer 102, and at least two adjacent antennas 1051 in the row direction are arranged to form different voltage differences with the mirror layer 102, so that the antennas 1051 in the row direction and/or the column direction are arranged to form different voltage differences with the mirror layer 102.

For example, in one example, along the first row, the voltage difference between the antenna 1051 and the mirror layer 102 is V11, V12, V13, V14, and V15 in sequence, and the size of V11, V12, V13, V14, and V15 may be V11 ═ V12 ═ V15, V13 ═ V14, but the sizes of V11 and V13 are not equal, or V11, V12, V13, V14, and V15 are all different, and the number of antennas 1051 is not limited in the embodiments of the present disclosure.

As shown in fig. 1 and 6, the antennas 1051 have sub-wavelength periodic structures on both the x-axis and the y-axis, and the z-axis is perpendicular to the plane of the x-axis and the y-axis, so that the exit angles of the reflected light rays can be controlled on the xz plane and the yz plane, and the "abnormal" reflection of the reflected light can be realized.

For example, fig. 7 is a schematic plan view of another sub-wavelength antenna unit provided in at least one embodiment of the present disclosure, as shown in fig. 7, the sub-wavelength antenna unit 105 includes a plurality of annular antennas 1051, the antennas 1051 are arranged in concentric circles, different voltages V between the antennas 1051 and the mirror layer 102 are different, different phase changes of reflected light or transmitted light at different positions of the super-surface are induced, and reflected light or transmitted light at different angles can be obtained according to the speed of the phase changes d Φ/dx. For example, in fig. 7, a plurality of antennas 1051 are shown, and the voltage difference formed between the first antenna and the mirror layer 102 and between the fifth antenna and the mirror layer 102 in the direction from the center of the circle to the center of the circle is equal in magnitude, and is V1; the voltage difference formed between the second antenna and the mirror layer 102 and between the sixth antenna and the mirror layer 102 is equal in magnitude, and is V2; the voltage difference formed between the third antenna and the mirror layer 102 and between the seventh antenna and the mirror layer 102 is equal in magnitude, and is V3; the voltage difference formed between the fourth antenna and the mirror layer 102 and between the eighth antenna and the mirror layer 102 is equal in magnitude to V4, and thus the four voltage differences V1, V2, V3, and V4 are cyclically operated. The voltage difference that can be formed between the first antenna and the mirror layer 102 and between the fifth antenna and the mirror layer 102 with the same power line is V1; the voltage difference between the second antenna and the mirror layer 102 and between the sixth antenna and the mirror layer 102 can be both V2 by using the same power line; the voltage differences that can be formed between the third antenna and the mirror layer 102 and between the seventh antenna and the mirror layer 102 with the same power line are both V3; the same power line can be used to form the voltage difference between the fourth antenna and the mirror layer 102 and between the eighth antenna and the mirror layer 102 to be V4, thereby saving the number of power lines. Of course, the cyclic operation may be performed with two voltage differences V1 and V2 as a period, or may be performed with three voltage differences V1, V2, and V3 as a period, which is not limited in the embodiment of the disclosure.

For example, fig. 8 is a schematic plan view of a sub-wavelength antenna unit and a connection portion according to at least one embodiment of the present disclosure, as shown in fig. 8, the sub-wavelength antenna unit 105 includes a plurality of antennas 1051, and voltage differences between first, second, third, and fourth antennas and a mirror layer along the x-axis are V1, V2, V3, and V4, respectively, and use V1, V2, V3, and V4 as a repeating unit, and voltage differences between fifth, sixth, seventh, eighth, and mirror layers are V1, V2, V3, and V4, respectively, so as to form a new cycle. And each antenna 1051 included in the sub-wavelength antenna unit 105 is electrically connected to the power supply line 108 through the connection portion 109.

For example, fig. 9 is a schematic perspective view of a sub-wavelength antenna unit and a connection portion according to at least one embodiment of the present disclosure, as shown in fig. 9, a sub-wavelength antenna unit 105 and a power line 108 are electrically connected through a connection portion 109, and the power line 108 is configured to apply a voltage to a corresponding antenna 1051, for example, each power line 108 is connected to at least two antennas 1051, so as to apply the same voltage to the antennas 1051 connected thereto.

For example, as shown in fig. 9, an insulating layer 110 is provided between the subwavelength antenna unit 105 and the power supply line 108, and the insulating layer 110 is formed entirely on the plane where the antenna 1051 is formed. The connection portion 109 is provided in a via structure 110a penetrating the power line 108 and the insulating layer 110, so that the antenna 1051 and the corresponding power line 108 are electrically connected through the connection portion 109.

For example, referring to fig. 1 to 9, the material of the sub-wavelength antenna unit 105 may be any material that can generate plasmon electromagnetic response to light of a corresponding wavelength and has conductivity. The material of the sub-wavelength antenna unit 105 includes a conductive metal, the conductive metal includes gold, silver, aluminum, or copper, and the like, and the material of the sub-wavelength antenna unit 105 may further include at least one of a conductive metal oxide and conductive graphene, which is not limited in this disclosure.

For example, referring to fig. 1 to 9, the material of the mirror layer 102 is a metal having high reflectivity to light with a specific wavelength and electrical conductivity. For example, the material of the mirror layer 102 includes gold, silver, aluminum, or copper, and the like, and the material of the mirror layer 102 may further include at least one of a conductive metal oxide and conductive graphene, which is not limited in this respect by the embodiment of the disclosure.

For example, in one example, the material of the conductive layer 103 includes indium tin oxide, aluminum or gallium doped zinc oxide, indium gallium zinc oxide, graphene, or conductive nitride, or the like. The material of the conductive layer 103 only needs to satisfy the requirement of generating plasmon electromagnetic response to light with corresponding wavelength, and the voltage difference existing in the conductive layer 103 can make the electron concentration in the conductive layer 103 change regionally, so as to regulate and control the real part of the dielectric constant of the material in the region.

For example, in one example, the electron concentration of the conductive layer 103 changes with the applied voltage, and it suffices that the real part of the dielectric constant is close to 0.

For example, the material of the dielectric layer 104 includes an inorganic insulating layer material or an organic insulating layer material, and the material of the inorganic insulating layer can ensure adhesion between the dielectric layer 104 and the conductive layer 103, so that the connection between the dielectric layer 104 and the conductive layer 103 is tighter.

At least one embodiment of the present disclosure provides a light beam control apparatus, which has at least one of the following beneficial technical effects:

(1) in the beam control device provided in at least one embodiment of the present disclosure, the first adhesive layer is disposed between the dielectric layer and the sub-wavelength antenna unit to achieve a tighter connection between the dielectric layer and the sub-wavelength antenna unit, thereby ensuring structural stability of the entire beam control unit.

(2) In the light beam control device provided by at least one embodiment of the present disclosure, the electron concentration of the effective area in the conductive layer can be adjusted and controlled by changing the voltage difference formed between the sub-wavelength antenna unit and the mirror layer.

The following points need to be explained:

(1) the drawings of the embodiments of the disclosure only relate to the structures related to the embodiments of the disclosure, and other structures can refer to the common design.

(2) For purposes of clarity, the thickness of layers or regions in the figures used to describe embodiments of the present disclosure are exaggerated or reduced, i.e., the figures are not drawn on a true scale.

(3) Without conflict, embodiments of the present disclosure and features of the embodiments may be combined with each other to arrive at new embodiments.

The above description is only a specific embodiment of the present disclosure, but the scope of the present disclosure is not limited thereto, and the scope of the present disclosure should be subject to the scope of the claims.

Claims

1. An optical beam steering apparatus comprising: a substrate, and a mirror layer, a conductive layer, a dielectric layer and a sub-wavelength antenna unit laminated on the substrate,

wherein the sub-wavelength antenna elements and the mirror layer are configured to apply different voltages;

a first adhesive layer is disposed between the dielectric layer and the sub-wavelength antenna element.

2. The optical beam steering device of claim 1, wherein a chemical bond is formed between the first adhesive layer and the dielectric layer and between the first adhesive layer and the sub-wavelength antenna element, the first adhesive layer configured to bond the dielectric layer and the sub-wavelength antenna element.

3. The light beam control device according to claim 1 or 2, wherein the thickness of the first bonding layer is 1 nm to 50 nm, and the material of the first bonding layer includes at least one of a simple metal of titanium, a simple metal of chromium, a simple metal of tungsten, and a simple metal of niobium.

4. The optical beam steering device of claim 1, wherein the first adhesive layer has an electrical conductivity, and an orthographic projection of the first adhesive layer on the substrate and an orthographic projection of the sub-wavelength antenna element on the substrate at least partially overlap.

5. The light beam steering device of claim 1, wherein the first adhesive layer is insulative, and an orthographic projection of the sub-wavelength antenna element on the substrate is within an orthographic projection of the first adhesive layer on the substrate.

6. The optical beam control device of claim 1, wherein a second adhesive layer is disposed between the substrate and the mirror layer, the second adhesive layer configured to adhere the substrate and the mirror layer.

7. The light beam control device of claim 6, wherein a chemical bond is formed between the second adhesive layer and the substrate and between the second adhesive layer and the mirror layer to bond the substrate and the mirror layer.

8. The optical beam control apparatus according to claim 6, wherein the thickness of the second adhesive layer is 1 nm to 1000 nm, and the material of the second adhesive layer includes at least one of a simple metal of titanium, a simple metal of chromium, a simple metal of tungsten, and a simple metal of niobium.

9. The light beam control device according to any one of claims 6 to 8, wherein a material of the first adhesive layer and a material of the second adhesive layer are the same or different.

10. The beam steering apparatus of claim 1, wherein the sub-wavelength antenna unit comprises a plurality of antennas, each of the antennas being rod-shaped.

11. The beam control device of claim 10, wherein at least two adjacent antennas are configured to form different voltage differences with the mirror layer.

12. The beam steering device of claim 1, wherein the sub-wavelength antenna unit comprises a plurality of antennas arranged in an array.

13. Optical beam control device according to claim 12, wherein at least two adjacent antennas in the column direction are arranged to form a different voltage difference with the mirror layer and/or at least two adjacent antennas in the row direction are arranged to form a different voltage difference with the mirror layer.

14. The beam steering apparatus of claim 1, wherein the sub-wavelength antenna unit comprises a plurality of antennas in a shape of a loop, the plurality of antennas being arranged in concentric circles.

15. The beam control device of claim 14, wherein at least two adjacent antennas are configured to form different voltage differences with the mirror layer.

16. A beam control apparatus according to any one of claims 10 to 15, further comprising at least two power lines, the plurality of antennas and the power lines being electrically connected by respective connection portions, each power line being electrically connected to one or more of the antennas, the power lines being configured to apply a voltage to the corresponding antenna.

17. The beam steering arrangement of claim 16, wherein an insulating layer is disposed between the sub-wavelength antenna element and the power line, the connection being disposed in a via structure that extends through the power line and the insulating layer.

18. The beam steering device of claim 1, wherein the material of the sub-wavelength antenna element comprises at least one of a conductive metal, a conductive metal oxide, and conductive graphene.

19. The optical beam steering apparatus of claim 1, wherein the material of the mirror layer comprises at least one of a metal having reflectivity and conductivity, a conductive metal oxide, and conductive graphene.

20. A beam control device according to claim 1, wherein the material of the conductive layer comprises indium tin oxide, indium zinc oxide or indium gallium zinc oxide.

21. The optical beam steering apparatus of claim 1, wherein the material of the dielectric layer comprises an inorganic insulating material or an organic insulating material.