Optical device and method for manufacturing the same

Abstract

The present invention relates to an optical device and a method for manufacturing the same, and more particularly, to an optical device comprising: a lower electrode; an insulating film formed on the lower electrode; a plurality of upper electrodes formed on the insulating film; and a plurality of variable conductivity patterns disposed on the insulating film adjacent to the plurality of upper electrodes, respectively. The plurality of upper electrodes comprise a plurality of first electrodes and a plurality of second electrodes arranged alternately, the spacing between the plurality of first electrodes being the same as the spacing between the plurality of second electrodes, the second electrode being disposed between adjacent plurality of first electrodes, the distance between one of the adjacent plurality of first electrodes and the second electrode being a first distance, the distance between another of the adjacent plurality of first electrodes and the second electrode being a second distance, and the second distance being different from the first distance.

Description

Technical Field

[0001] The present invention relates to an optical device and a manufacturing method thereof, and more particularly, to an optical modulator and a manufacturing method thereof. Background Art

[0002] Optical devices that change the transmission, reflection, polarization, phase, intensity, path, etc. of incident light are widely used in various optical devices. In addition, optical modulators of various structures are provided in order to control the above properties in a desired manner in an optical system.

[0003] Previous wave modulators have used liquid crystals or micro-unit mirrors. Liquid crystal modulators operate by applying an electrical or thermal signal. Liquid crystal modulators use the property of determining the direction of the liquid crystal array according to the signal to adjust the response to incident light. Micro-mirror modulators (e.g., digital mirror devices (DMDs)) use the principle of adjusting the direction of multiple micro-mirrors to reflect incident light in the desired direction.

[0004] Metasurface is an optical material with a thin thickness that changes the characteristics of incident light. Compared with existing technologies using liquid crystals or micro mirrors, metasurfaces show improved modulation performance and can reduce the size of elements to a size several dozen times smaller than the wavelength. In addition, the required form of reflected light or transmitted light can be obtained according to the characteristics of the metasurface, so it is actively studied as a core technology for flat lenses, ultra-small holography, Lidar, cloaking, etc.

[0005] Graphene has good characteristics as a material constituting a super surface. First, its characteristics are changed by the applied voltage. If a super surface using graphene is constructed, the modulation degree can be adjusted by applying an electrical signal. The above method is a method of adjusting the Fermi energy of graphene, so a faster modulation speed can be obtained compared to the previous method using liquid crystal. Second, the size of graphene plasma is hundreds of times smaller than the size of a photon in free space. This is an important characteristic for miniaturizing super surfaces. Summary of the invention

[0006] An object of the present invention is to provide an optical device having improved optical characteristics.

[0007] Another object of the present invention is to provide a method for manufacturing an optical device having improved optical characteristics.

[0008] The optical device of the concept of the present invention may include: a lower electrode; an insulating film formed on the above-mentioned lower electrode; a plurality of upper electrodes formed on the above-mentioned insulating film; and a plurality of variable conductivity patterns, which are arranged on the above-mentioned insulating film and are respectively adjacent to the plurality of the above-mentioned upper electrodes, the plurality of the above-mentioned upper electrodes include a plurality of first electrodes and a second electrode arranged alternately, the spacing between the plurality of the above-mentioned first electrodes is the same as the spacing between the plurality of the above-mentioned second electrodes, the plurality of the above-mentioned second electrodes are arranged between the adjacent plurality of the above-mentioned first electrodes, the distance between one of the adjacent plurality of the above-mentioned first electrodes and the above-mentioned second electrode is a first distance, the distance between another of the adjacent plurality of the above-mentioned first electrodes and the above-mentioned second electrode is a second distance, and the second distance is different from the first distance.

[0009] An optical device of another concept of the present invention may include: a lower electrode; an insulating film formed on the above-mentioned lower electrode; a plurality of upper electrodes on the above-mentioned insulating film; and a plurality of variable conductivity patterns on the above-mentioned insulating film, respectively arranged adjacent to the plurality of the above-mentioned upper electrodes, the plurality of the above-mentioned upper electrodes include a plurality of first electrodes and second electrodes arranged alternately, the plurality of the above-mentioned variable conductivity patterns include a plurality of first variable conductivity patterns and a second variable conductivity patterns respectively arranged adjacent to the plurality of the above-mentioned first electrodes and the second electrodes, the plurality of the above-mentioned first electrodes and the second electrodes have the same first width, the plurality of the above-mentioned first variable conductivity patterns have a second width, and the plurality of the above-mentioned second variable conductivity patterns have a third width different from the second width.

[0010] Another concept of an optical device of the present invention may include: a lower electrode; an insulating film formed on the above-mentioned lower electrode; a plurality of upper electrodes formed on the above-mentioned insulating film; and a plurality of variable conductivity patterns, which are arranged on the above-mentioned insulating film adjacent to the plurality of upper electrodes, respectively, the plurality of upper electrodes include a plurality of first electrodes and second electrodes arranged alternately, the plurality of variable conductivity patterns include a plurality of first variable conductivity patterns and a second variable conductivity patterns respectively arranged adjacent to the plurality of first electrodes and second electrodes, the adjacent plurality of first electrodes and second electrodes are separated by a first distance via the above-mentioned first variable conductivity pattern, the adjacent plurality of first electrodes and second electrodes are separated by a second distance via the above-mentioned second variable conductivity pattern, and the first distance and the second distance are different from each other.

[0011] An optical device according to another concept of the present invention may include: a lower electrode; an insulating film formed on the lower electrode; a plurality of upper electrodes formed on the insulating film; and a plurality of variable conductivity patterns arranged on the insulating film adjacent to the plurality of upper electrodes, respectively, the conductivity of the plurality of variable conductivity patterns changing according to a voltage applied to the plurality of upper electrodes, the plurality of variable conductivity patterns comprising graphene having at least one layer, the plurality of upper electrodes comprising a plurality of first electrodes and a second electrode arranged alternately, the spacing between the plurality of first electrodes being the same as the spacing between the plurality of second electrodes, the plurality of second electrodes being arranged between adjacent plurality of first electrodes, the distance between one of the adjacent plurality of first electrodes and the second electrode being a first distance, the distance between another of the adjacent plurality of first electrodes and the second electrode being a second distance, the second distance being different from the first distance, and the plurality of upper electrodes The variable conductivity pattern includes a plurality of first variable conductivity patterns and a plurality of second variable conductivity patterns respectively arranged adjacent to the first electrode and the second electrode, the plurality of first electrodes and the plurality of second electrodes have the same first width, the plurality of first variable conductivity patterns respectively have a second width, the plurality of second variable conductivity patterns respectively have a third width different from the second width, the third width is greater than the second width, the second width is half of the first distance, and the third width is half of the second distance, the plurality of first variable conductivity patterns are combined with the plurality of first electrodes, and the plurality of second variable conductivity patterns are combined with the plurality of second electrodes, and when a first voltage is applied to the plurality of first electrodes and a second voltage different from the first voltage is applied to the plurality of second electrodes, different Fermi energies are provided to the plurality of first variable conductivity patterns and the plurality of second variable conductivity patterns.

[0012] An optical device according to another concept of the present invention may include: a lower electrode; an insulating film formed on the lower electrode; a plurality of upper electrodes formed on the insulating film; and a plurality of variable conductivity patterns arranged on the insulating film adjacent to the plurality of upper electrodes, respectively, the conductivity of the plurality of variable conductivity patterns changing according to a voltage applied to the plurality of upper electrodes, the plurality of variable conductivity patterns including graphene having at least one layer, the plurality of upper electrodes including a plurality of first electrodes and a plurality of second electrodes arranged alternately, the plurality of variable conductivity patterns including a plurality of first variable conductivity patterns and a plurality of second variable conductivity patterns arranged adjacent to the plurality of first electrodes and the second electrodes, the plurality of first electrodes and the second electrodes having the same first width, the plurality of first variable conductivity patterns having a second width, the plurality of second variable conductivity patterns having a third width different from the second width, the third width being greater than the second width, and the plurality of first electrodes The first electrodes and the plurality of second electrodes are alternately arranged, one of the plurality of second electrodes is configured between adjacent first electrodes, a distance between one of the adjacent first electrodes and the one of the plurality of second electrodes is a first distance, a distance between another first electrode of the adjacent first electrodes and the one of the plurality of second electrodes is a second distance, the second distance is different from the first distance, the second width is half of the first distance, the third width is half of the second distance, the plurality of first variable conductivity patterns are combined with the plurality of first electrodes, the plurality of second variable conductivity patterns are combined with the plurality of second electrodes, and when a first voltage is applied to the plurality of first electrodes and a second voltage different from the first voltage is applied to the plurality of second electrodes, different Fermi energies are provided to the plurality of first variable conductivity patterns and the plurality of second variable conductivity patterns.

[0013] The optical device of the present invention can adjust the phase while maintaining the amplitude of the mid-infrared reflected wave, or adjust the amplitude while maintaining the phase of the mid-infrared reflected wave. In other words, when incident on the optical device of the present invention, the amplitude and phase of the reflected wave can be adjusted independently. As described above, the optical device of the present invention can freely adjust the mid-infrared wave. The optical device of the present invention can be applied to lenses, beam steering devices for laser radars, ultra-wideband long-distance communications, active thermal radiation control, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention.

[0015] Figure 2 for Figure 1 A cross-sectional view along the A-A' line.

[0016] Figure 3 , Figure 4 , Figure 5 It is a three-dimensional diagram showing a method for manufacturing an optical device according to an embodiment of the present invention.

[0017] Figure 6 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention.

[0018] Figure 7 for Figure 6 A cross-sectional view along the A-A' line.

[0019] Figure 8 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention.

[0020] Fig. 9 for Figure 8 A cross-sectional view along the A-A' line.

[0021] Fig.10 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention.

[0022] Fig.11A and Fig. 11B They are Fig.10 Cross-sectional view along line A-A' and line BB'.

[0023] Fig.12 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to fully understand the composition and effect of the present invention, the preferred embodiments of the present invention are described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be embodied in various forms and can be subjected to various changes. However, through the description of this embodiment, the present invention will become complete and provide the full scope of the present invention to those skilled in the art to which the present invention belongs.

[0025] In this embodiment, when it is mentioned that a structural element is formed on other structural elements, it means that a third structural element can be directly formed on other structural elements or formed between them. In addition, in the figure, the thickness of the structural element is magnified in order to effectively illustrate the technical content. Throughout the specification, the same reference numerals represent the same structural elements.

[0026] The embodiments described in this specification will be described with reference to the ideal or illustrative cross-sectional views and / or top views of the present invention. In the figure, the thickness of the film and the region is magnified in order to effectively illustrate the technical content. Therefore, the region illustrated in the figure has a brief attribute, and the shape of the region illustrated in the figure is used to illustrate the specific form of the device region, rather than to limit the scope of the invention. In various embodiments of this specification, the terms first, second, third, etc. are used to describe various structural elements, but these structural elements are not limited to the above terms. These terms are only used to distinguish between two structural elements. The embodiments described and illustrated herein include self-complementary embodiments.

[0027] The terms used in this specification are used to illustrate the embodiments, but are not used to limit the present invention. In this specification, unless otherwise specified, the singular includes the plural. The terms "comprices" and / or "comprising" used in the specification mean that the structural elements mentioned do not exclude the existence or addition of one or more other structural elements.

[0028] Figure 1 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention. Figure 2 for Figure 1 A cross-sectional view along the A-A' line.

[0029] Reference Figure 1 and Figure 2 The optical device of the embodiment of the present invention may include a light modulator (LM). The light modulator LM includes a substrate SUB, a lower electrode LEL, an insulating film IL, an upper electrode UEL and a variable conductivity pattern (GA). The substrate SUB may include a semiconductor substrate such as a silicon substrate.

[0030] A lower electrode LEL may be formed on the substrate SUB. The lower electrode LEL may be in a flat plate shape. The lower electrode LEL may include at least one of a metal material (e.g., titanium, tantalum, tungsten, gold, silver, copper, or aluminum) and a conductive metal nitride (e.g., titanium nitride or tantalum nitride). A ground voltage may be applied to the lower electrode LEL. Although not shown in the figure, a film (e.g., an insulating film) may be additionally formed between the substrate SUB and the lower electrode LEL.

[0031] An insulating film IL may be formed on the lower electrode LEL. The insulating film IL may include a silicon oxide film, a silicon nitride film, or a silicon nitride oxide film. As an example, the thickness of the insulating film IL may be greater than the thickness of the lower electrode LEL.

[0032] A plurality of upper electrodes UEL may be formed on the insulating film IL. The plurality of upper electrodes UEL may include a plurality of first electrodes EL1 and a plurality of second electrodes EL2. The plurality of upper electrodes UEL, that is, the plurality of first electrodes EL1 and the second electrodes EL2 may include at least one of a metal substance (e.g., titanium, tantalum, tungsten, gold, silver, copper, or aluminum) and a conductive metal nitride (e.g., titanium nitride or tantalum nitride). The plurality of first electrodes EL1 and the second electrodes EL2 may include the same conductive substance.

[0033] The plurality of first electrodes EL1 and the second electrodes EL2 may extend parallel to each other along the first direction D1. From a planar viewpoint, the plurality of first electrodes EL1 and the second electrodes EL2 may be in a linear form or a rod form. The plurality of first electrodes EL1 and the second electrodes EL2 may be arranged alternately along the second direction D2. In other words, the second electrode EL2 may be arranged between the plurality of adjacent first electrodes EL1. The first electrode EL1 may be arranged between the plurality of adjacent second electrodes EL2.

[0034] The plurality of first electrodes EL1 may have a first width W1. The plurality of second electrodes EL2 may also have a first width W1. In other words, substantially, the plurality of first electrodes EL1 and the second electrodes EL2 may have the same width. As another embodiment of the present invention, the width of the plurality of first electrodes EL1 may be different from the width of the plurality of second electrodes EL2, and is not particularly limited to Figure 2 The form shown.

[0035] The spacing between the plurality of first electrodes EL1 may be the first spacing P1. The spacing between the plurality of second electrodes EL2 may also be the first spacing P1. In other words, the plurality of first electrodes EL1 may be arranged at the first spacing. The plurality of second electrodes EL2 may also be arranged at the first spacing.

[0036] The distance between the first electrode EL1 and the adjacent second electrode EL2 along the second direction D2 may be a first distance L1. The distance between the second electrode EL2 and the adjacent first electrode EL1 along the second direction D2 may be a second distance. The second distance L2 may be greater than the first distance L1.

[0037] The second electrode EL2 between the adjacent plurality of first electrodes EL1 may be offset at the center position between the adjacent plurality of first electrodes EL1. The distance between one of the adjacent plurality of first electrodes EL1 and the second electrode EL2 may be the first distance L1, and the distance between another of the adjacent plurality of first electrodes EL1 and the second electrode EL2 may be the second distance L2.

[0038] The plurality of first electrodes EL1 may apply a first voltage V1 in common, and the plurality of second electrodes EL2 may apply a second voltage V2 in common. The second voltage V2 may be different from the first voltage V1.

[0039] A variable conductivity pattern GA may be formed on the insulating film IL. The plurality of variable conductivity patterns GA may include a plurality of first variable conductivity patterns GA1 and a plurality of second variable conductivity patterns GA2.

[0040] The plurality of first variable conductivity patterns GA1 and the second variable conductivity patterns GA2 may extend parallel to each other along the first direction D1. From a plane point of view, the plurality of first variable conductivity patterns GA1 and the second variable conductivity patterns GA2 may be in a line form or a rod form. The plurality of first variable conductivity patterns GA1 and the second variable conductivity patterns GA2 may be alternately arranged along the second direction D2.

[0041] The plurality of first variable conductivity patterns GA1 may be respectively disposed adjacent to the sidewalls of the plurality of first electrodes EL1. The plurality of second variable conductivity patterns GA2 may be respectively disposed adjacent to the sidewalls of the plurality of second electrodes EL2. The first variable conductivity pattern GA1 may be in contact with the adjacent first electrode EL1. In other words, the first variable conductivity pattern GA1 may be electrically connected to the adjacent first electrode EL1. The second variable conductivity pattern GA2 may be in contact with the adjacent second electrode EL2. In other words, the second variable conductivity pattern GA2 may be electrically connected to the adjacent second electrode EL2.

[0042] The plurality of first variable conductivity patterns GA1 may have a second width W2. The plurality of second variable conductivity patterns GA2 may have a third width W3. The third width W3 may be greater than the second width W2. As an example, the second width W2 may be half of the first distance L1, and the third width W3 may be half of the second distance L2.

[0043] The plurality of variable conductivity patterns GA may change their conductivity according to the voltage applied to the plurality of upper electrodes UEL. As an example, the plurality of variable conductivity patterns GA may include graphene, indium tin oxide (ITO) or black phosphorus. Preferably, the variable conductivity pattern GA may include a two-dimensional material having a single-layer structure.

[0044] Graphene may have a monolayer structure or a multilayer structure of 2 to 10 layers. The plurality of variable conductivity patterns GA including graphene may have a two-dimensional structure. As an example, the variable conductivity pattern GA including graphene may form a super surface using graphene plasmon.

[0045] The optical device of the embodiment of the present invention applies a first voltage V1 to the plurality of first electrodes EL1 and applies a second voltage V2 to the plurality of second electrodes EL2. Thus, different Fermi energies can be provided to the plurality of first variable conductivity patterns GA1 combined with the plurality of first electrodes EL1 and the plurality of second variable conductivity patterns GA2 combined with the plurality of second electrodes EL2. As an example, when the plurality of variable conductivity patterns GA include graphene, light can be modulated by adjusting the Fermi energy of the graphene.

[0046] In the optical device of the present invention, a plurality of first electrodes EL1 and second electrodes EL2 can be arranged alternately, thereby, the two resonance characteristics can complement each other. The optical device of the present invention can appropriately combine the first voltage V1 and the second voltage V2, thereby, the phase can be adjusted while maintaining the amplitude of the mid-infrared reflected wave, or the amplitude can be adjusted while maintaining the phase of the mid-infrared reflected wave. In other words, when the mid-infrared ray is incident on the optical modulator LM of the present invention, the amplitude and phase of the reflected wave can be adjusted independently by adjusting the first voltage V1 and the second voltage V2.

[0047] As described above, the optical device of the embodiment of the present invention can freely adjust the mid-infrared wave. Therefore, the optical device of the embodiment of the present invention can be applied to lenses, laser radar beam steering devices, ultra-wideband long-distance communications, active thermal radiation control, etc.

[0048] Figure 3 , Figure 4 , Figure 5 It is a three-dimensional diagram showing a method for manufacturing an optical device according to an embodiment of the present invention.

[0049] Reference Figure 3 , a lower electrode LEL may be formed on the substrate SUB. The lower electrode LEL may include at least one of a metal material and a conductive metal nitride. The lower electrode LEL may be formed by an evaporation process or a gold plating process.

[0050] An insulating film IL may be formed on the lower electrode LEL. The insulating film IL may include a silicon oxide film, a silicon nitride film, or a silicon nitride oxide film. The insulating film IL may be formed by an evaporation process.

[0051] Reference Figure 4 A plurality of upper electrodes UEL may be formed on the insulating film IL. The plurality of upper electrodes UEL may include a plurality of first electrodes EL1 and a plurality of second electrodes EL2 that are alternately arranged.

[0052] As an example, the process of forming a plurality of upper electrodes UEL includes a process of forming an electrode film on the insulating film IL and a process of patterning the electrode film to form a plurality of first electrodes EL1 and a second electrode EL2. As another example, the process of forming a plurality of upper electrodes UEL includes a process of directly forming a plurality of first electrodes EL1 and a second electrode EL2 on the insulating film IL using a mask. The plurality of first electrodes EL1 and the second electrode EL2 may be formed at the same time. Furthermore, the plurality of second electrodes EL2 may be formed after the plurality of first electrodes EL1 are formed.

[0053] Reference Figure 5 , a variable conductivity film GAL may be formed on the plurality of upper electrodes UEL. As an example, the process of forming the variable conductivity film GAL includes the process of performing a steam process on the front surface of the substrate SUB. As another example, the process of forming the variable conductivity film GAL may include the step of transferring the variable conductivity film GAL to the plurality of upper electrodes UEL.

[0054] Refer again Figure 1 and Figure 2 , a plurality of variable conductivity patterns GA may be formed by patterning the variable conductivity film GAL. The plurality of variable conductivity patterns GA may include a plurality of first variable conductivity patterns GA1 and a second variable conductivity pattern GA2. The plurality of first variable conductivity patterns GA1 and the second variable conductivity patterns GA2 may be formed adjacent to sidewalls of the plurality of first electrodes and the second electrodes, respectively.

[0055] Figure 6 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention. Figure 7 for Figure 6 In this embodiment, the cross-sectional view of the line A-A' is omitted. Figure 1 and Figure 2 A detailed description of the repeated technical features of the optical devices described is given, and the differences are explained in detail.

[0056] Reference Figure 6 and Figure 7 In essence, the plurality of first variable conductivity patterns GA1 and the second variable conductivity patterns GA2 may have the same width. For example, the plurality of first variable conductivity patterns GA1 may have a second width W2, and the plurality of second variable conductivity patterns GA2 may also have a second width W2.

[0057] Figure 8 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention. Fig. 9 for Figure 8 In this embodiment, the cross-sectional view of the line A-A' is omitted. Figure 1 and Figure 2A detailed description of the repeated technical features of the optical devices described is given, and the differences are explained in detail.

[0058] Reference Figure 8 and Fig. 9 The plurality of first electrodes EL1 may include a first side wall SW1 and a second side wall SW2 facing the first side wall SW1. The second side wall SW2 may be spaced apart from the first side wall SW1 along the second direction D2. The plurality of second electrodes EL2 may include a first side wall SW1 and a second side wall SW2 facing the first side wall SW1.

[0059] The plurality of first variable conductivity patterns GA1 may be disposed between the first electrode EL1 and the second electrode EL2 adjacent to the first electrode EL1 along the second direction D2. In other words, the first variable conductivity pattern GA1 may be disposed between the second side wall SW2 of the first electrode EL1 and the first side wall SW1 of the second electrode EL2. The first variable conductivity pattern GA1 may be separated from the second side wall SW2 of the first electrode EL1, and may also be separated from the first side wall SW1 of the second electrode EL2. In other words, the first variable conductivity pattern GA1 may be separated from the plurality of first electrodes EL1 and the second electrode EL2.

[0060] The plurality of second variable conductivity patterns GA2 may be disposed between the second electrode EL2 and the first electrode EL1 adjacent to the second electrode EL2 along the second direction D2. In other words, the second variable conductivity pattern GA2 may be disposed between the second side wall SW2 of the second electrode EL2 and the first side wall SW1 of the first electrode EL1. The second variable conductivity pattern GA2 may be separated from the second side wall SW2 of the second electrode EL2, and may also be separated from the first side wall SW1 of the first electrode EL1. In other words, the second variable conductivity pattern GA2 may be separated from the plurality of first electrodes EL1 and the second electrode EL2.

[0061] Fig.10 FIG. 1 is a perspective view showing an optical device according to an embodiment of the present invention. Fig.11A and Fig. 11B They are Fig.10 In this embodiment, the cross-sectional view of the A-A' line and the BB' line is omitted. Figure 1 and Figure 2 A detailed description of the repeated technical features of the optical devices described is given, and the differences are explained in detail.

[0062] Reference Fig.10 , Fig.11A and Fig. 11B, a plurality of upper electrodes UEL may be formed on the insulating film IL. The plurality of upper electrodes UEL may include a plurality of first electrodes EL1 and a plurality of second electrodes EL2. The first electrodes EL1 and the second electrodes EL2 may be in the form of plates, respectively. From a planar point of view, the plurality of first electrodes EL1 and the second electrodes EL2 may be in the form of polygons (e.g., quadrangles).

[0063] The plurality of first electrodes EL1 and second electrodes EL2 may be arranged two-dimensionally on the insulating film. The plurality of first electrodes EL1 and second electrodes EL2 may be arranged alternately along the second direction D2. Furthermore, the plurality of first electrodes EL1 and second electrodes EL2 may be arranged alternately along the first direction D1.

[0064] For example, four second electrodes EL2 may be arranged around one first electrode EL1. The four second electrodes EL2 may be adjacent to the one first electrode EL1 along the first direction D1 and the second direction D2. Four first electrodes EL1 may be arranged around one second electrode EL2. The four first electrodes EL1 may be adjacent to the one second electrode EL2 along the first direction D1 and the second direction D2.

[0065] In essence, the first electrodes EL1 and the second electrodes EL2 may have the same size. In essence, the first electrodes EL1 and the second electrodes EL2 may have the same planar shape.

[0066] The plurality of first electrodes EL1 may be arranged at a first pitch P1 along the first direction D1. The plurality of first electrodes EL1 may be arranged at a first pitch P1 along the second direction D2. The plurality of second electrodes EL2 may be arranged at a first pitch P1 along the second direction D2.

[0067] A variable conductivity pattern GA may be formed on the insulating film IL. The variable conductivity pattern GA may be in a grid form. Specifically, the variable conductivity pattern GA may include: a plurality of first extensions EP1 extending along the first direction D1; a plurality of second extensions EP2 extending along the first direction D1; a plurality of third extensions EP3 extending along the second direction D2; and a plurality of fourth extensions EP4 extending along the second direction D2.

[0068] The plurality of first extension portions EP1 and the second extension portions EP2 may be arranged alternately along the second direction D2. The plurality of third extension portions EP3 and the fourth extension portions EP4 may be arranged alternately along the first direction D1. The plurality of first extension portions EP1 and the third extension portions EP3 may have a second width W2. The plurality of second extension portions EP2 and the fourth extension portions EP4 may have a third width W3.

[0069] The first extension portion EP1 , the second extension portion EP2 , the third extension portion EP3 , and the fourth extension portion EP4 may intersect with each other to form an opening OP. The first electrode EL1 or the second electrode EL2 may be disposed in the opening OP.

[0070] Fig.12 The 3D diagram of the optical device of the embodiment of the present invention is shown. Figure 1 and Figure 2 A detailed description of the repeated technical features of the optical devices described is given, and the differences are explained in detail.

[0071] The optical modulator LM of the present invention can omit the substrate SUB below the lower electrode LEL. For example, although not shown in the figure, a support body for supporting the optical modulator LM can be arranged at both ends of the optical modulator LM. Fig.12 The active area of ​​the light modulator LM shown may be suspended in the air.

[0072] The lower electrode LEL of this embodiment may be an electrode that transmits mid-infrared rays. As an example, the lower electrode LEL may include a transparent conducting oxide (TCO). The transparent conductive oxide may be selected from the group consisting of indium tin oxide (ITO), fluorine-doped tin oxide (FTO), zinc oxide (ZnO), titanium dioxide (TiO2), gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO) and combinations thereof. As another example, the lower electrode LEL may include doped silicon.

Claims

1. An optical device, characterized in that: include: Lower electrode; an insulating film formed on the lower electrode; A plurality of upper electrodes formed on the insulating film; and A plurality of variable conductivity patterns are disposed on the insulating film adjacent to the plurality of upper electrodes, respectively, and the conductivity of the plurality of variable conductivity patterns changes according to a voltage applied to the plurality of upper electrodes. A plurality of the above-mentioned variable conductivity patterns include graphene having at least one layer, The plurality of upper electrodes include a plurality of first electrodes and second electrodes arranged alternately, The spacing between the plurality of first electrodes is the same as the spacing between the plurality of second electrodes. The plurality of second electrodes are arranged between the plurality of adjacent first electrodes. The distance between one of the plurality of adjacent first electrodes and the second electrode is a first distance, The distance between another one of the adjacent plurality of first electrodes and the second electrode is a second distance, The second distance is different from the first distance. The plurality of variable conductivity patterns include a plurality of first variable conductivity patterns and a plurality of second variable conductivity patterns respectively arranged adjacent to the first electrode and the second electrode, the plurality of first electrodes and the plurality of second electrodes have the same first width, the plurality of first variable conductivity patterns respectively have a second width, and the plurality of second variable conductivity patterns respectively have a third width different from the second width. The third width is greater than the second width, the second width is half of the first distance, and the third width is half of the second distance. The plurality of first variable conductivity patterns are combined with the plurality of first electrodes, and the plurality of second variable conductivity patterns are combined with the plurality of second electrodes. When a first voltage is applied to the first electrodes and a second voltage different from the first voltage is applied to the second electrodes, different Fermi energies are provided to the first variable conductivity patterns and the second variable conductivity patterns.

2. The optical device according to claim 1, characterized in that: The plurality of first variable conductivity patterns are directly in contact with one side of the first electrode. The plurality of second variable conductivity patterns directly contact one side of the second electrode.

3. The optical device according to claim 2, characterized in that: The plurality of first variable conductivity patterns are separated from adjacent second electrodes. The plurality of second variable conductivity patterns are respectively spaced apart from adjacent first electrodes.

4. The optical device according to claim 1, characterized in that: The plurality of first variable conductivity patterns are separated from the adjacent first electrodes and the second electrodes. The plurality of second variable conductivity patterns are separated from adjacent first electrodes and second electrodes.

5. The optical device according to claim 1, characterized in that: The lower electrode is in the form of a flat plate.

6. The optical device according to claim 1, characterized in that: The upper electrode is in the form of a line extending along the first direction. The plurality of variable conductivity patterns extend along the upper electrode in the first direction.

7. The optical device according to claim 1, characterized in that: applying a first voltage to the plurality of first electrodes, A second voltage is commonly applied to the plurality of second electrodes.

8. An optical device, characterized in that: include: Lower electrode; an insulating film formed on the lower electrode; A plurality of upper electrodes formed on the insulating film; and A plurality of variable conductivity patterns are disposed on the insulating film adjacent to the plurality of upper electrodes, respectively, and the conductivity of the plurality of variable conductivity patterns changes according to a voltage applied to the plurality of upper electrodes. A plurality of the above-mentioned variable conductivity patterns include graphene having at least one layer, The plurality of upper electrodes include a plurality of first electrodes and second electrodes arranged alternately, The plurality of variable conductivity patterns include a plurality of first variable conductivity patterns and a plurality of second variable conductivity patterns respectively arranged adjacent to the plurality of first electrodes and the plurality of second electrodes. The plurality of first electrodes and second electrodes have the same first width. The plurality of first variable conductivity patterns have a second width, The plurality of second variable conductivity patterns have a third width different from the second width, and the third width is greater than the second width. The plurality of first electrodes and the plurality of second electrodes are arranged alternately, one of the plurality of second electrodes is arranged between adjacent first electrodes, a distance between one of the adjacent first electrodes and the one of the plurality of second electrodes is a first distance, a distance between another first electrode of the adjacent first electrodes and the one of the plurality of second electrodes is a second distance, and the second distance is different from the first distance. The second width is half of the first distance, the third width is half of the second distance, The plurality of first variable conductivity patterns are combined with the plurality of first electrodes, and the plurality of second variable conductivity patterns are combined with the plurality of second electrodes. When a first voltage is applied to the first electrodes and a second voltage different from the first voltage is applied to the second electrodes, different Fermi energies are provided to the first variable conductivity patterns and the second variable conductivity patterns.

9. The optical device according to claim 8, characterized in that: The adjacent first electrodes and second electrodes are separated by a first distance via the first variable conductivity pattern. The adjacent first electrodes and second electrodes are separated by a second distance via the second variable conductivity pattern. The first distance and the second distance are different from each other.

10. The optical device according to claim 8, characterized in that: The spacing between the plurality of first electrodes is the same as the spacing between the plurality of second electrodes.

11. The optical device according to claim 8, characterized in that: The plurality of upper electrodes are in the form of lines extending along a first direction, The plurality of variable conductivity patterns extend in the first direction along the plurality of upper electrodes.

12. The optical device according to claim 11, characterized in that: The plurality of first electrodes and second electrodes are alternately arranged along a second direction intersecting the first direction.

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