KR101775989B1 - Optical filter including array of hybrid nanostructures and method of preparing the same - Google Patents

Abstract

An optical filter including an array of hybrid nanostructures and a method of manufacturing the same are provided.

Description

[0001] OPTICAL FILTER INCLUDING ARRAY OF HYBRID NANOSTRUCTURES AND METHOD OF PREPARING THE SAME [0002]

The present invention relates to an optical filter comprising an array of hybrid nanostructures and a method of making the same.

Optical filters are known to be a key component in a wide range of optical applications, including optical communications, displays, and imaging. Optical filters in micros are generally composed of dielectric thin films with a thickness corresponding to the wavelength of light, and light of a specific wavelength is transmitted or reflected due to interference caused by this structure. On the other hand, one of the promising alternatives to achieve the goal of miniaturization is plasmon grating, which operates on interference between surface plasmon polarites (SPPs) [Barnes, WL; Dereux, A .; Ebbesen, TW Surface plasmon subwavelength optics. Nature 2003, 424, (6950), 824-830]. Various designs based on this plasmon grating are leading various visible light filters. In all cases, a large number of grating elements resulted in improved transmission efficiency and a narrower linewidth due to the increased momentum between light and SPPs. This type of filter provides several important advantages over traditional filters, but it is difficult to control the transmittance, the performance decreases as the number of grating elements decreases, the transmission of light in multiple bands is not easily controlled Suggest the limit of the filter. In addition, when it is desired to design a specific line-shaped transmission band, it is very difficult or impossible to realize a thin film filter or a plasmonic grating driven by an interference phenomenon.

The present invention provides an optical filter in which hybrid nanostructures are arranged and a method of manufacturing the same.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description.

A first aspect of the present application provides a nanostructure comprising: a nanostructure disposed on a transparent substrate; And an array of hybrid nanostructures comprising at least a portion of a surface of the nanostructure and a first layer coated on a surface of the transparent substrate on which the nanostructure is not disposed, The positive number of the permittivity < RTI ID = 0.0 > epsilon < / RTI > Wherein the first layer comprises a material in which the value of epsilon ', which is the real part of the dielectric constant epsilon, expressed as Equation 1 in the wavelength band in which the optical filter operates is negative:

[Formula 1]

The dielectric constant ε = ε '+ iε ".

The optical filter according to an embodiment of the present invention has a function of simultaneously transmitting light even in a plurality of bands based on a mechanism differentiated from an interference phenomenon due to a thin film laminated structure or a plasmonic phenomenon due to a noble metal concave and convex structure. The optical filter according to an embodiment of the present invention can transmit light of a plurality of bands simultaneously by arranging hybrid nano-structures of different thicknesses or diameters and materials or a combination thereof. By controlling the number and spacing of the hybrid nanostructures, Can be effectively controlled. Unlike the plasmonic filter, the transmission bandwidth of light is kept constant regardless of the number of hybrid nanostructures of the optical filter, and the total transmittance can be adjusted according to the number of the hybrid nanostructures or the interval between the elements. This is very different from the plasmonic filter in that the transmittance and the transmission wavelength can be controlled independently.

When the nanostructures having different diameters are arranged based on these functions, a multi-band filter capable of transmitting light in individual bands corresponding to the diameters of the respective nanostructures, rather than one band, can be realized. Furthermore, it is possible to arrange the hybrid nanostructures having different thicknesses or diameters and / or materials in a certain order (for example, arranging the hybrid nanostructures at regular intervals) It is possible to form specific lineshape and bandwidth by using a 'sculpting technique'.

The multi-band filter according to the present invention can be applied to various fields such as bio-imaging and optical communication. In the bioimaging, it is possible to simultaneously measure the lights of the phosphors having different wavelengths. Optical communication is expected to be applicable to multiplexing technology.

In this paper, we propose a new paradigm which is different from the existing optical filters' operation principle, so that the control of the filter performance is facilitated and the functions that could not be realized become possible. It is expected that the basic and practical development of various application fields will occur radically.

1A and 1B are schematic diagrams of an optical filter according to an embodiment of the invention.
2 is a schematic view of a method of manufacturing an optical filter according to an embodiment of the present invention;
3A is a schematic diagram of an optical filter according to one embodiment of the present disclosure.
3B is an SEM image of an optical filter according to an embodiment of the present invention. The scale bar is 1 占 퐉.
FIG. 3C is a schematic diagram of a setup for measuring far field transmission through an optical filter according to an embodiment of the invention; FIG.
FIG. 3D shows the transmission of an optical filter according to one embodiment of the present invention, which modeled the setup according to FIG. 3C in two dimensions and numerically simulated as a function of diameter and wavelength.
4A is a schematic diagram of an optical filter according to one embodiment of the present disclosure having exemplary parameters.
Figure 4b shows the power transfer efficiency determined numerically as a function of the top Ag layer thickness and wavelength of the optical filter according to one embodiment of the present invention.
4C shows power transfer efficiency through an optical filter having a top Ag layer of 30 nm thickness as a function of wavelength according to one embodiment of the invention.
Figure 5 shows, in an embodiment of the invention, the power transfer efficiency (a) through an optical filter (a) without an upper Ag layer and an optical filter (b) without a lower Ag layer, which are numerically simulated as a function of core diameter and wavelength Lt; / RTI >
Figure 6 shows measurement results for Mie scattering for a core-shell (top) and an uncoated (bottom) cylinder, in one embodiment of the invention. (a) is a schematic diagram of a core-shell ZnO-Ag cylinder (top) and an uncoated ZnO cylinder (bottom), the Ag shell thickness being fixed at 30 nm. (b) is an analytically calculated scattering cross-section as a function of diameter and wavelength, and (c) is scattering (black curve) and absorption cross section (blue curve) as a function of wavelength for core-diameter of 180 nm. (d) is a normalized angular scattering distribution at a wavelength of 591 nm and a core-diameter of 180 nm, corresponding to the fundamental absorption resonance in the core-shell cylinder, and the angle? is defined in (a).
Figure 7 shows the analytically calculated absorption cross-section as a function of diameter and wavelength for a ZnO cylinder (a) surrounded by an Ag shell of 30 nm thickness and an uncoated ZnO cylinder (b) in one embodiment of the present invention will be.
Figure 8a shows the transfer efficiencies calculated with a two-dimensional model on the Ag filter for the incidence of condensed light on an optical filter (red curve) and a basic Ag film (black curve) according to one embodiment of the present invention . The optical filter was formed with a core-diameter of 180 nm, an upper Ag layer 30 nm thick, and a lower Ag layer 15 nm thick. The basic Ag film is 45 nm thick.
FIG. 8B illustrates the interaction between the light condensed onto the optical filter (top) and the basic Ag film (bottom) according to one embodiment of the present invention, wherein the error of the pointing vector along the y- And the real part. The diagrams labeled 1, 2, and 3 show the interactions occurring at 475 nm, 612 nm, and 750 nm, respectively, as indicated by the arrows in FIG.
Figure 9 shows the electric field distribution within the optical filter of Figure 8A, where at an operating wavelength of 612 nm (plotted as 2), the electric field was shown to be primarily localized within the nanostructure, whereas 475 nm And the electric field at 750 nm (plotted as 3) show little intensity within the same size.
10A is an SEM image of three uncoated ZnO nanorods on an Ag film prior to deposition of a first Ag layer according to one embodiment of the present application, wherein the left and right views are magnified and full images of the nanorod, respectively . The nominal diameters correspond respectively to 186 nm, 156 nm and 125 6 nm from top to bottom. The left and right scale bars are 250 nm and 500 nm, respectively.
10B is an optical microscope image of three nanorods after deposition of the first Ag layer according to one embodiment of the present invention. The scale bar is 2.5 占 퐉.
FIG. 10C shows the transmission (top) and the numerically simulated transmission (bottom) measured through the hybrid device normalized by transmission through the Ag film around three optical filters according to one embodiment of the present application.
Figure 10d shows experimental and calculated wavelength-diameter variance from other hybrid nano-rods according to one embodiment of the present application. Exp1 and Exp2 correspond to two sets of hybrid nano rods, each individually manufactured.
The upper part of FIG. 10E is an SEM image of an increasingly tapered ZnO nanorod on the Ag film before deposition of the second Ag layer. The scale bar is 500 nm. The bottom is an optical microscope image of the same ZnO nanorod after deposition of the second Ag layer. The scale bar is 2.5 占 퐉.
Figure 11 shows the response from light polarized at right angles to the nano-rod axis in the three optical filters as in Figure 10c. (a) is an optical microscope image of an optical filter emitted by polarized white light in parallel (left image) and at right angles (right image), (b) 186 ± 6 nm (red curve), 156 ± 6 nm ), And three optical filters including a ZnO nanorod having a diameter of 125 +/- 6 nm (blue curve), as measured by transmission through a surrounding Ag film. The scale bar is 2.5 占 퐉.
FIGS. 12A to 12C are graphs showing the transmission reaction of the hybrid nanostructure according to an embodiment of the present invention.
Figure 13 is a graphical representation of an embodiment of a hybrid NR-Ag filter according to one embodiment of the present invention, wherein (a) the hybrid NR-Ag filter according to the present invention, and (b) And the dependence of the transmission linearity is shown.
Figure 14 shows the absolute transmission through an infinite array of conventional plasmonic nanocavities (red), hybrid nano-rods (blue) and substantial hybrid filters (black) according to the present invention, in one embodiment of the present invention.
Figure 15 shows the transmittance of the hybrid nanoload filter from an infinite array at different periods of 500 nm to 800 nm, in one embodiment of the invention.
16A shows simulated transmission from an array of hybrid nano-load filters for different numbers of elements, in one embodiment of the invention.
Figure 16b shows the simulated transmission from an array of substantially usable hybrid filters each of which has a rectangular cross section, in one embodiment of the present invention.
Figure 16c shows, in one embodiment of the present invention, the simulated transmittance (top) through an infinite array of nanodrode filters having a diameter of 170 nm for different periods and the maximum transmittance for the same assembly of filters as a function of period Bottom).
17 shows, in one embodiment of the present application, (a) simulated transmission from an infinite array of 170 nm-sized hybrid filters with periods less than 500 nm and (b) 400 nm from left to right, 300 nm And an electric field distribution from a unit cell at 200 nm periodicity.
18 shows an optical filter system according to an embodiment of the present invention.
FIG. 19 shows calculation results derived based on an optical filter system according to an embodiment of the present invention.
FIG. 20 shows a calculation result derived based on an optical filter system according to an embodiment of the present invention.
FIG. 21 is a graph illustrating the results of calculation of an optical filter system based on three kinds of nanoload combination as shown in FIG. 17B in the embodiment of the present invention. (A) P1 = P2 = P3 = 475 nm and D1 = 100 (B) the transmittance derived from the system where P1 = P2 = P3 = 600 nm and D1 = 160 nm, D2 = 180 nm, D3 = 200 nm will be.
FIG. 22 is a photograph of a pixel formed by combining and arranging a plurality of nanowires, each having a different diameter, according to an embodiment of the present invention, taken by a light microscope.
23 is an SEM image of an optical filter in an embodiment of the present invention.

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. It should be understood, however, that the present invention may be embodied in many different forms and is not limited to the embodiments and examples described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout this specification, when a part is referred to as being "connected" to another part, it is understood that it includes not only "directly connected" but also "electrically connected" do.

Throughout this specification, when a member is "on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as "including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

As used herein, the terms "about," " substantially, "and the like are used herein to refer to or approximate the numerical value of manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to prevent unauthorized exploitation by unauthorized intruders of the mentioned disclosure.

The term " step "or" step of ~ " as used throughout the specification does not imply "step for.

Throughout this specification, the term "combination (s) thereof " included in the expression of the machine form means a mixture or combination of one or more elements selected from the group consisting of the constituents described in the expression of the form of a marker, Quot; means at least one selected from the group consisting of the above-mentioned elements.

Throughout this specification, the description of "A and / or B" means "A or B, or A and B".

Hereinafter, embodiments of the present invention are described in detail, but the present invention is not limited thereto.

A first aspect of the present application provides a nanostructure comprising: a nanostructure disposed on a transparent substrate; And an array of hybrid nanostructures comprising at least a portion of a surface of the nanostructure and a first layer coated on a surface of the transparent substrate on which the nanostructure is not disposed, The positive number of the permittivity < RTI ID = 0.0 > epsilon < / RTI > Wherein the first layer comprises a material in which the value of epsilon ', which is the real part of the dielectric constant epsilon, expressed as Equation 1 in the wavelength band in which the optical filter operates is negative:

[Formula 1]

The dielectric constant ε = ε '+ iε ".

Throughout this specification, the term "permittivity" refers to a measure of the resistance that occurs when an electric field is created in a medium, which is a measure of how an electric field affects or receives the dielectric medium, Lt; / RTI > The dielectric constant can be calculated by the following equation:

[Formula 1]

The dielectric constant ε = ε '+ iε ".

The dielectric function (or relative permittivity, ε = ε '+ iε) is a function describing the optical properties of a material and is defined by a complex number. N = n + ik), but relative permittivity is a more appropriate representation in the region where the light corresponds to the wavelength. The refractive index and the dielectric constant can easily be interchanged by the following equation:

^{(1) ε '= n 2} - k 2;

(2)? "= 2 nk;

Where n is a real number representing the ratio of the speed of light (c) and the speed of light (phase velocity, v) in the material;

(3) n = c / v

k represents the extinction coefficient, which is a coefficient indicating the weakening of the light wedge when the light travels through the material.

The combination of n and k can represent the optical properties of all materials, and ε 'and ε "are more appropriate when describing the phenomenon occurring in fine structures. This is due to the phonon structure of the material And the electronic structure. The models that theoretically predict the ε of a material vary, including the Lorentz model, the Drude model, and the Debye relaxation model (see Chapter 9 in 'Absorption and Scattering of Light by Small Particles'', CF Bohren and DR Huffman, Wiley-VCH 2004. The dielectric constant is closely related to the electrical susceptibility of the material, χ _e, and can be expressed as:

(4) ε = 1 + χ _e.

The electrical susceptibility thus represents the degree of polarization of the material when an electric field is applied. In the case of metals, the value of ε 'is negative due to the high conductivity. Loss is expressed as " epsilon "(Lourtioz, J.-M. et al. (2005) Photonic crystals: towards nanoscale photonic devices. The selection of suitable materials for the first layer, the second layer, the nanostructure, etc. in the selection of suitable materials, and the selection of such suitable materials may be accomplished as described above, The dielectric constant of each material can be measured and / or calculated by using a measuring method such as refractive index, data, or the like.

In one embodiment of the present invention, the characteristic dimension or diameter and / or the material of each of the nanostructures included in each of the hybrid nanostructures may be the same or different from each other. The transmission band of light can be determined according to the diameter or the material of the nanostructure. Band filters that simultaneously transmit light in a plurality of wavelength bands by including nanostructures of different thickness, diameter, and / or material.

In one embodiment of the present invention, the total transmittance can be controlled by controlling the number or arrangement interval of the hybrid nanostructures.

In one embodiment of the present invention, the width and linehape of the transmission wavelength band can be adjusted by adjusting the arrangement and / or arrangement of the hybrid nanostructures. For example, hybrid nanostructures having different thicknesses or diameters and / or materials may be arranged in a predetermined order (e.g., in a certain order) with a variety of arrangements of the hybrid nanostructures (e.g., arranging hybrid nanostructures at regular intervals) The 'fragmentation technique' by means of the arrangement allows the formation of specific lineshape and bandwidth.

FIG. 18 shows an optical filter in which a plurality of hybrid nanostructures having different diameters are arranged. It is possible to realize a filter of a plurality of bands by varying not only the diameter of the hybrid nanostructures but also the arrangement interval.

In one embodiment of the present invention, the hybrid nanostructure may be nano-sized, but may not be limited thereto. The hybrid nanostructure may have a nano-sized thickness or diameter, for example, a thickness or diameter of about 100 nm to about 5,000 nm.

In one embodiment of the invention, the optical filter can be used for a light source that includes focused light or plane waves.

In one embodiment of the present invention, the operating wavelength band of the optical filter may include a visible light range or an infrared range.

1A and 1B are schematic diagrams of an optical filter according to an embodiment of the present invention.

In one embodiment of the present invention, the nanostructure 400 includes a material having a positive value of ε ', which is a real part of a permittivity ε expressed by the following equation 1 in a wavelength range in which the optical filter operates, ; The first layer 500 includes a material having a negative value of a real part ε 'of a dielectric constant ε expressed by the following formula 1 in a wavelength region in which the optical filter operates:

[Formula 1]

The dielectric constant ε = ε '+ iε ".

In one embodiment of the present invention, the nanostructure 400 may have a thickness smaller than an operating wavelength of the optical filter. For example, when the operating wavelength of the optical filter is visible light or infrared light, the nanostructure 400 may have a thickness or diameter smaller than the operating wavelength.

1A, the thickness t of the first layer 500 formed on at least a portion of the surface of the nanostructure 400 may be greater than the thickness of the first layer 500 and the thickness of the nanostructure 400. In one embodiment, A < a < a or 0 < t / a < 1 with respect to the thickness a of the first layer (or the length from the center of the nanostructure to the top of the first layer) a. In addition, the thickness t of the first layer 500 may be thinner than the radius of the nanostructure 400, but may not be limited thereto. This condition is satisfied when the real part ε 'of the dielectric constant of the material forming the nanostructure 400 is different from the symbol of the first layer 500 or the real part ε' of the dielectric constant of the first layer and the second layer , A condition necessary to form a combination for minimizing light scattering.

In one embodiment of the invention, the hybrid nanostructure comprises a first layer coated on at least a portion of a surface of the nanostructure disposed on the transparent substrate and a surface of the transparent substrate on which the nanostructure is not disposed . For example, the first layer is formed on at least a portion of the surface of the nanostructure that is not in contact with the substrate (FIG. 1A) or all surfaces that are not in contact (FIG. 1B) The first layer is formed on a surface of the nanostructure corresponding to a portion through which light passes.

In one embodiment of the present invention, the nanostructure may additionally include a second layer formed under the first layer, but the present invention is not limited thereto. In one embodiment of the present invention, the second layer 300 includes a material having a negative value of ε ', which is a real part of the permittivity ε indicated by the formula 1.

The first layer and the second layer may comprise the same or different materials. The thickness of the second layer may be in a range satisfying the thickness condition of the first layer with respect to the thickness a of the first layer 500 plus the radius of the nanostructure 400, The layer may have a thickness that is thinner than the first layer.

In one embodiment of the present invention, the first layer and the second layer may be the minimum thickness that can not transmit light. The thickness of the first layer and the second layer may be adjusted to control the transmission efficiency.

The thickness of the first layer 500 formed on at least a part of the surface of the nanostructure 400 may be varied according to the material contained in the first layer 500. In one embodiment of the present invention, A <0 or 0 <t / a with respect to a thickness (or a length from the center of the nanostructure to the top of the first layer) a of the thickness of the first layer 500 and the radius of the nanostructure 400 &Lt; 1. In addition, the thickness t of the first layer 500 may be thinner than the radius of the nanostructure 400, but may not be limited thereto. This condition is satisfied when the real part ε 'of the dielectric constant of the material forming the nanostructure 400 is different from the symbol of the first layer 500 or the real part ε' of the dielectric constant of the first layer and the second layer , A condition necessary to form a combination for minimizing light scattering.

In one embodiment herein, the thickness of the first layer satisfies the thickness condition according to the material forming the first layer, for example, the first layer has a thickness in the range of about 10 nm to about 70 nm From about 10 nm to about 50 nm, from about 10 nm to about 50 nm, from about 10 nm to about 40 nm, from about 10 nm to about 30 nm, from about 10 nm to about 20 nm, from about 20 nm to about 70 nm , From about 30 nm to about 70 nm, from about 40 nm to about 70 nm, from about 50 nm to about 70 nm, or from about 60 nm to about 70 nm.

In one embodiment herein. The second layer may vary in thickness depending on the material it is in, and may have a thickness in the range of, for example, about 5 nm to about 50 nm, about 5 nm to about 40 nm, about 5 nm to about 30 nm, From about 5 nm to about 10 nm, from about 10 nm to about 50 nm, from about 20 nm to about 50 nm, from about 30 nm to about 50 nm, or from about 40 nm to about 50 nm have.

In one embodiment herein, the second layer is about 10 nm to about 20 nm thick and the first layer can be about 25 nm to about 45 nm thick.

In one embodiment of the present invention, the first layer includes a material having a negative value of a permittivity ε, which is a real part of permittivity ε expressed by Equation 1, in accordance with an operating wavelength band of an optical filter to be used can do. In one embodiment of the present invention, when the operating wavelength band of the optical filter includes a visible light range, the first layer may include Ag, Au, Pt, Al, Si, Ge, Cu, Doped Si, and P-doped Ge, and the like. In one embodiment of the present invention, when the operating wavelength band of the optical filter includes an infrared range, the first layer may be formed of TiN, InP, Si, Ge, ZnO, GaN, InGaN, InN, Cu, , And doped semiconductors such as Si-doped GaN, and the like.

In one embodiment of the present invention, the nanostructure includes a material having a positive value of ε ', which is a real part of a permittivity ε expressed by the following equation 1 in a wavelength band in which the optical filter operates, A material having a bandgap greater than the operating wavelength band of the optical filter. The nanostructure can be used without limitation as long as it is an inorganic or organic semiconductor material satisfying the above conditions. The nanostructure can be selected depending on the operating wavelength range of the optical filter in the visible light range or the infrared range. The nano-structure, when the operating wavelength band of the optical filter including a visible light range, for example, C (diamond), Si, Ge, Sn, SiC, S _8, Se, Te, BN, BP, BAs ZnS, ZnS, ZnTe, CuCl, Cu ₂ S, PbSe, PbS, ObTe, SnS, SnS ₂ , SnTe, B ₁₂ As ₂ , AlN, AlP, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb CdSe, CdTe, InGaP, InGaN, InN, InP, InAs, InSb, BaTiO ₂ , BaTiO ₃ , PbSeTe, Tl ₂ SnTe ₅ , Tl ₂ GeTe ₅ , Bi ₂ Te ₃ , Cd ₃ P ₂ , Cd ₃ As _{2, Cd 3 Sb 2, ZnsP} 2, Zn 3 As 2, Zn 3 Sb 2, TiO 2, Cu 2 O, CuO, UO 2, UO 3, Bi 2 O 3, SnO 2, SrTiO 3, LiNbO 3, La _{2 CuO 4, PbI 2, MoS} 2, VO 2, V 2 O 3, GaSe, Bi 2 S 3, NiO, CuInSe 2, Ag 2 S, FeS 2, Cu 2 ZnSnS 4, CuZnSbS, Cu 2 SnS 3, Si _{1 - x Ge x, Si 1} - x Sn x, Al x Ga 1 -x As, In x Ga 1 - x As, In x Ga 1 -x P, Al x In 1 - x As, Al x In 1 - _{x Sb, GaAsN, GaAsP, GaAsSb} , AlGaN, AlGaP, InGaN, InAsSb, InGaSb, AlGaInP, AlGaAsP, IGaAsP, InGaAsSb, InAsSbP, AlInAsP, AlGaAsN, InGaAsN, InAsAsN, GaAsSbN, GaInNAsSb, GaInAs It may comprise a dielectric material selected from the SbP, CdZnTe, HgCdTe, HgZnTe, HgZnSe, and Cu (In, Ga) Se ₂ the group consisting of, but may not be limited thereto. The nano-structure, when the operating wavelength band of the optical filter including the infrared range, for example, C (diamond), Si, Ge, Sn, SiC, S _8, Se, Te, BN, BP, BAs, ZnO, ZnSe, ZnS, ZnTe, CuCl, Cu 2 S, PbSe, PbS, ObTe, SnS, SnS 2, SnTe, B 12 As 2, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, CdS, CdSe, CdTe, InGaP, InGaN, InN, InP, InAs, InSb, BaTiO ₂ , BaTiO ₃ , PbSeTe, Tl ₂ SnTe ₅ , Tl ₂ GeTe ₅ , Bi ₂ Te ₃ , Cd ₃ P ₂ , Cd ₃ As ₂ , Cd _{3 Sb 2, ZnsP 2, Zn} 3 As 2, Zn 3 Sb 2, TiO 2, Cu 2 O, CuO, UO 2, UO 3, Bi 2 O 3, SnO 2, SrTiO 3, LiNbO 3, La 2 CuO 4 _{, PbI 2, MoS 2, VO} 2, V 2 O 3, GaSe, Bi 2 S 3, NiO, CuInSe 2, Ag 2 S, FeS 2, Cu 2 ZnSnS 4, CuZnSbS, Cu 2 SnS 3, Si 1 - x _{Ge x, Si 1 -x Sn x} , Al x Ga 1 - x As, In x Ga 1 - x As, In x Ga 1 -x P, Al x In 1 - x As, Al x In 1 - x Sb, GaAsS, GaAsP, GaAsSb, AlGaN, AlGaP, InGaN, InAsSb, InGaSb, AlGaInP, AlGaAsP, IGaAsP, InGaAsSb, InAsSbP, AlInAsP, AlGaAsN, InGaAsN, InAsAsN, GaAsSbN, GaInNAsSb, GaInAsSbP, CdZ nTe, HgCdTe, HgZnTe, HgZnSe, and Cu (In, Ga), but may include a material selected from the group consisting of Se _2, it may not be limited thereto.

In one embodiment of the present invention, the nanostructure may be doped with Al or Ga, but the present invention is not limited thereto.

In one embodiment of the present invention, by controlling the thickness or the diameter of the nanostructure, the transmission wavelength or the transmission wavelength region can be controlled, and the transmission band of light can be determined. The diameter of the nanostructure may be determined according to the operating wavelength of the optical filter, for example, the visible range and / or the infrared range, and the material contained in the nanostructure. For example, since the dielectric constant varies depending on the material in the desired operating wavelength range of the optical filter, a suitable thickness or diameter that satisfies the size combination of the dielectric constant versus the nanostructure that minimizes light scattering can be determined through calculation .

In one embodiment of the present invention, the nanostructure may have a thickness or diameter smaller than the operating wavelength of the optical filter. For example, when the operating wavelength band of the optical filter includes a visible light range, when the nanorod comprises ZnO, the thickness or diameter of the nanostructure may range from about 50 nm to about 400 nm or less, From about 50 nm to about 200 nm, from about 50 nm to about 350 nm, from about 50 nm to about 300 nm, from about 50 nm to about 250 nm, from about 50 nm to about 200 nm, from about 50 nm to about 150 nm nm, about 50 nm to about 100 nm, about 100 to about 390 nm, about 100 nm to about 350 nm, about 100 nm to about 300 nm, about 100 nm to about 250 nm, about 100 nm to about 200 nm, About 150 nm to about 300 nm, about 150 nm to about 250 nm, about 150 nm to about 200 nm, about 200 to about 100 nm, about 150 nm to about 400 nm, about 150 nm to about 390 nm, 390 nm, from about 200 nm to about 350 nm, from about 200 nm to about 300 nm, or from about 200 nm to about 250 nm.

In one embodiment of the present invention, when the operating wavelength region of the optical filter includes an infrared range, when the nanorod includes ZnO, the thickness or diameter of the nanostructure may be about 50 nm to about 5,000 nm And may range from about 50 nm to about 4,500 nm, from about 50 nm to about 4,000 nm, from about 50 nm to about 3,500 nm, from about 50 nm to about 3,000 nm, from about 50 nm to about 2,500 nm, From about 50 nm to about 2,000 nm, from about 50 nm to about 1,500 nm, from about 50 nm to about 1,000 nm, from about 50 nm to about 500 nm, from about 50 nm to about 250 nm, from about 50 nm to about 100 nm, from about 500 nm to about 5,000 nm, from about 500 nm to about 5,000 nm, from about 1,000 nm to about 5,000 nm, from about 1,500 nm to about 5,000 nm, from about 2,000 nm to about 5,000 nm, from about 2,500 nm to about 5,000 nm, From about 5,000 nm, from about 3,500 nm to about 5,000 nm, from about 4,000 nm to about 5,000 nm, or from about 4,500 nm to about 5,000 nm Can.

The thickness of the first layer 500 formed on at least a part of the surface of the nanostructure 400 depends on the material of the first layer 500, A <0 or 0 <t / a with respect to a thickness (or a length from the center of the nanostructure to the top of the first layer) a of the thickness of the first layer 500 and the radius of the nanostructure 400 &Lt; 1. Also, the thickness t of the first layer 500 may be thinner than the radius of the nanostructure 400.

For example, the characteristic dimension or diameter of the nanostructure may be less than or equal to about 400 nm, less than or equal to about 350 nm, less than or equal to about 300 nm, less than or equal to about 250 nm, less than or equal to about 200 nm, About 150 nm or less, or about 100 nm or less, and the lower limit of the length may be, for example, about 10 nm, about 50 nm, about 70 nm, or about 100 nm.

In one embodiment of the present invention, the nanostructure is not limited in its shape but may include, for example, a nanorod, a nanowire, a nanowire, a nanowall, or a nanodisc, But may not be limited. The nanorod or nanobar may be in the form of a conical column, a cylindrical column, a triangular column, a quadrangular column, a pentagonal column, or a hexagonal column, or may include, but is not limited to, .

In one embodiment of the present invention, the length of the nanostructure is not limited, and may be, for example, equal to or longer than the thickness or diameter of the nanostructure, but may not be limited thereto. The nanostructure may have a length of less than about 10 microns, such as from about 1 to about 10 microns, for example, from about 1 to about 8 microns, from about 1 to about 7 microns, from about 1 to about 5 microns, from about 1 To about 3 占 퐉, from about 3 to about 10 占 퐉, from about 5 to about 10 占 퐉, or from about 8 to about 10 占 퐉.

In one embodiment of the present invention, the optical filter may additionally include, but is not limited to, a wetting layer formed under the second layer. The wetting layer can reduce the surface roughness of the second layer. The wetting layer may have a thickness ranging from about 0.5 nm to about 10 nm, for example, from about 0.5 nm to about 8 nm, from about 0.5 nm to about 6 nm, from about 0.5 nm to about 4 nm, from about 0.5 nm to about 2 nm , From about 1 nm to about 10 nm, from about 3 nm to about 10 nm, from about 5 nm to about 10 nm, or from about 8 nm to about 10 nm. The wetting layer may include, but is not limited to, Ge, or Al-doped Ag.

FIGS. 1A and 1B are schematic diagrams of an optical filter according to an embodiment of the invention, comprising a substrate 100; A wetting layer (200) formed on the substrate; A second layer (300) formed on the wetting layer; A nanostructure (400) disposed on the second layer; And a first layer (500) coated on a surface of the nanostructure and a second layer on which the nanostructure is not disposed. FIG. 1A shows an embodiment in which the first layer 500 is formed on a part of the surface of the nanostructure 400, and FIG. 1B shows an embodiment in which the first layer 500 is formed on the entire surface of the nanostructure. As shown in FIGS. 1A and 1B, as the first layer 500 is coated on the surface and the lower side of the nanostructure 400, a shell or a cavity is formed by the first layer, Can be formed.

In one embodiment of the invention, the hybrid nanostructure comprises a first layer coated on at least a portion of a surface of the nanostructure disposed on the transparent substrate and a surface of the transparent substrate on which the nanostructure is not disposed . For example, the first layer is formed on at least a part of the surface of the nanostructure that is not in contact with the base material or on all surfaces that are not in contact with the surface of the nanostructure, And is formed on the first layer on the surface of the nanostructure.

In one embodiment of the present invention, light can be filtered and adjusted in wavelength using a single nano-sized element in the form of an integrated nanostructure surrounded by a shell formed by the first layer. The principle of light transmission is derived from the ability of the shell to highly concentrate (concentrate) light into the nanostructure and generate strong absorption resonance, or equivalently, to cancel out light scattering by the shell.

In one embodiment of the present invention, the first layer and the second layer may be formed only on the upper and lower portions of the nanostructure, respectively. Since it is unnecessary to uniformly coat the nanostructure concentrically around the nanostructure, The restrictions on manufacturing can be mitigated and the integration of the device into an on-chip platform can be facilitated. Furthermore, unlike the plasmon grating-type filter, which requires an increased number of uneven grating elements to achieve maximum efficiency, a single element according to one embodiment of the present invention, i.e., a hybrid nanostructure, It does not depend on the number of elements for lineshape. This allows the hybrid nanostructure as a single element to realize an ultimate-sized optical filter and provides numerous applications such as nanoscale communication devices and fabrication of ultra high resolution pixel arrays.

In one embodiment of the invention, the dielectric constant of a material is a function of wavelength, so that at a particular wavelength band, epsilon 'is positive or negative. Therefore, in one embodiment of the present invention, in the optical filter, the transmission performance is exerted only at the wavelength band where the signs of the first layer and the second layer and the ε 'of the nanostructure are different. For example, in the case of an optical filter comprising a second Ag layer, a ZnO nanostructure and a first Ag layer, ZnO is positive in the visible range and ε 'of Ag is negative. Therefore, the combination of the two materials weakens scattering in the visible range and can enhance the transmittance.

In one embodiment of the present invention, the polarization direction of the light incident on the optical filter is fixed in the same direction as the axis of the nanostructure, so that a dipole in the first layer formed by the incident light, The scattering of light is canceled by the interference between the dipoles and the transmittance of the optical filter can be increased. For example, in the case of an optical filter including a second Ag layer, a ZnO nanostructure, and a first Ag layer, a polarization existing in the Ag layer formed in response to light and a polarization existing in the ZnO nanostructure core ), The structure of the Ag-ZnO-Ag becomes locally transparent, and thus the resonance effect can be exhibited. The transmission efficiency is derived from the destructive interference of light scattering between the shell and the nanostructure. Light consists of an oscillating electric field and a magnetic field. The phenomenon in which light is scattered by matter comes from the principle that an oscillating electric field reacts with the substance's dipole (dipole), causing the light to vibrate by vibrating the same pole. The dielectric constant, such as the above-described equation ε = 1 + χ _e , is a function of how much the material can be polarized in the electric field. If the real number of the dielectric constant of the material is negative, the phase of the pole changes 180 degrees and oscillates. At this time, if some of the constituents of the material have negative and positive epsilon (')', when they react with light, they interfere with each other and weaken the light. The size of the two components determines the extent of the cancellation of the light. At the same time strong destructive interference requires a small loss of light, which leads to the condition that the imaginary ε "must be weak." When scattering is reduced by strong destructive interference, the material appears to be effectively transparent to light, It becomes possible to transmit.

In one embodiment of the present invention, the optical filter may be used for, but is not limited to, bio-imaging. In bioimaging, the optical filter can simultaneously measure the lights of different phosphors of the wavelength band.

In one embodiment of the present invention, the optical filter may be used for optical communication but may not be limited thereto. In optical communication, the optical filter can be applied to a multiplexing technique.

In one embodiment of the present invention, the method of fabricating the optical filter comprises: disposing a nanostructure on a transparent substrate; And coating the first layer on the surface of at least a portion of the nanostructure and the surface of the transparent substrate on which the nanostructure is not disposed, Lt; RTI ID = 0.0 &gt; a &lt; / RTI &gt; of the permittivity &lt; RTI ID = 0.0 &gt; Wherein the first layer comprises a material having a negative value of a permittivity? Of a real part represented by the following formula 1 in a wavelength band in which the optical filter operates: to provide:

[Formula 1]

The dielectric constant ε = ε '+ iε ".

In one embodiment of the invention, it may further comprise coating the second layer on the substrate prior to placing the nanostructure on the substrate. The first layer and the second layer may include the same material, and the second layer may be coated with a thinner thickness than the first layer, but the present invention is not limited thereto.

1A and 1B are schematic diagrams of an optical filter according to an embodiment of the present invention.

In one embodiment of the present invention, the nanostructure 400 includes a material having a positive value of ε ', which is a real part of a permittivity ε expressed as the following equation 1 in a wavelength range in which the optical filter operates: ; The first layer 500 includes a material having a negative value of a permittivity? Of a real part expressed by the following formula 1 in a wavelength range in which the optical filter operates:

[Formula 1]

The dielectric constant ε = ε '+ iε ".

In one embodiment of the present invention, the nanostructure 400 may have a thickness smaller than an operating wavelength of the optical filter. For example, when the operating wavelength region of the optical filter is a visible light or an infrared region, the nanostructure 400 may have a thickness or diameter that is thinner than the operating wavelength range.

1A, the thickness t of the first layer 500 formed on at least a portion of the surface of the nanostructure 400 may be greater than the thickness of the first layer 500 and the thickness of the nanostructure 400. In one embodiment, A < a < a or 0 < t / a < 1 with respect to the thickness a of the first layer (or the length from the center of the nanostructure to the top of the first layer) a. In addition, the thickness t of the first layer 500 may be thinner than the radius of the nanostructure 400, but may not be limited thereto. This condition is satisfied when the real part ε 'of the dielectric constant of the material forming the nanostructure 400 is different from the symbol of the first layer 500 or the real part ε' of the dielectric constant of the first layer and the second layer , A condition necessary to form a combination for minimizing light scattering.

In one embodiment of the invention, it may further include, but is not limited to, coating the wetting layer on the substrate prior to coating the second layer. The wetting layer may reduce the surface roughness of the second layer, but may not be limited thereto. The wetting layer may have a thickness ranging from about 0.5 nm to about 10 nm, for example, from about 0.5 nm to about 8 nm, from about 0.5 nm to about 6 nm, from about 0.5 nm to about 4 nm, from about 0.5 nm to about 2 nm , From about 1 nm to about 10 nm, from about 3 nm to about 10 nm, from about 5 nm to about 10 nm, or from about 8 nm to about 10 nm. In one embodiment herein, the wetting layer may include, but is not limited to, Ge, or Al-doped Ag.

In one embodiment herein, the nanostructure array can be fabricated by methods known in the art, for example, through electron beam lithography processes, but may not be limited thereto. A photoresist may be formed on the second layer or substrate, and the shape, length, and arrangement of each nanostructure may be designed by an electron beam lithography process, but the present invention is not limited thereto. The nanostructures can be prepared by methods known in the art and can be, for example, but not limited to, vapor phase, solution phase, and solid phase or deposition methods . The gas-phase method includes a metal-organic vapor-phase epitaxy (MOVPE) process or a chemical vapor deposition (CVD) process, and may be, for example, grown on a substrate by MOVPE . The solution phase process may include hydrothermal synthesis, or solvent solvothermal, and the solid phase process may include, but is not limited to, molten salt synthesis. The deposition method may include, but is not limited to, a sputtering deposition method and an e-beam evaporation method. The nanostructure can be fabricated through a sputter deposition and a lift-off process, for example, by forming a pattern on a photoresist by an electron beam lithography and a developing process.

In one embodiment, the first layer and the second layer may be deposited or coated by a deposition or coating method known in the art, respectively, and the nanostructure may be subjected to electron beam lithography and developing procedures The photoresist may be formed by patterning the photoresist, followed by sputter deposition and lift-off processes, but the present invention is not limited thereto. The second layer and the first layer may be deposited using, for example, an e-beam evaporator, but are not limited thereto.

2 is a schematic view of a method of manufacturing an optical filter according to an embodiment of the present invention. One embodiment of the present invention will now be described in detail with reference to FIG.

First, a wetting layer 200 is formed on a substrate 100. The substrate may be any substrate including a dielectric material without limitation, and may be, for example, SiN, SiO ₂ , ITO, Al ₂ O ₃ , or quartz. The wetting layer 200 may be deposited using an e-beam evaporator, but may not be limited thereto. The wetting layer 200 reduces the surface roughness of the second layer to be subsequently deposited. The second layer 300 is then deposited using an e-beam evaporator on the deposited wetting layer 200. But may not be limited to, rapid thermal annealing at a temperature of about 300 DEG C under nitrogen flow in a low oxygen environment to prevent oxidation of the second layer 300. [ Then, a photoresist thin film is formed on the second layer 300, and the length, shape and arrangement pattern of each nanostructure are formed through an electron beam lithography and a developing process, followed by a sputtering deposition process A ZnO thin film having a thickness corresponding to the thickness of the nanostructure can be deposited. The photoresist may be removed through a lift-off process to realize the aligned nanostructure 400. FIG. At this time, the nanostructures 400 may be arranged on the second layer 300 in a desired number and spacing. The first layer 500 may then be deposited using an e-beam evaporator under the same conditions as described above to form the hybrid nanostructure. As shown in FIG. 1D, a first layer 500 is coated on the upper surface of the nanostructure 400 and a second layer 300 on which the nanostructure is not disposed to form a cavity.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following Examples are given for the purpose of helping understanding of the present invention, but the present invention is not limited to the following Examples.

[Example]

[Example 1]

Manufacture of ZnO nanorods

ZnO nanorods were grown on c-plane Al ₂ O ₃ substrates using metal-organic vapor-phase epitaxy (MOVPE) [Park, WI; Kim, DH; Jung, SW; Yi, GC metal organic vapor-phase epitaxial growth of vertically well-aligned ZnO nanorods. Appl Phys Lett 2002, 80, (22), 4232-4234]. Diethylzinc and oxygen were used as reactants and argon was used as the carrier gas. The ZnO nanorods were grown by a two-step MOVPE process with controlled length and diameter. In the first step, the fine ZnO nanorods were grown at 700 ° C. to 800 ° C. for 6 hours to a length of 4 μm to 5 μm. The lateral growth of the ZnO nanorods was then carried out at 450 ° C to 550 ° C for 2 hours to have an average diameter in the range of 100 nm to 240 nm.

Manufacture of hybrid nano-rods

As a substrate, 0.5 T quartz slides were prepared by supporting with 10 nm / 40 nm Ti / Au placement markers designed for photolithography. 1 nm Ge and 15 nm Ag films were sequentially deposited on the substrate in an e-beam evaporator of less than 10 ^-6 torr at deposition rates of 0.1 A / sec and 1.5 A / sec respectively, wherein the Ge layer was wetted layer to reduce the surface roughness of Ag. Then, in order to prevent oxidation of Ag, rapid heating annealing was performed at 300 ° C for 3 minutes under nitrogen flow in a low oxygen environment to improve the quality of Ag.

ZnO NRs in anhydrous ethanol was then drop-cast onto an Ag / Ge coated quartz slide. The slides were dried and plasma washed with Ar at 100 mA for 2 minutes. Individual NRs having a desired range of diameters were identified with a 15 kV FE-SEM and then an additional Ag layer of 30 nm was deposited in an e-beam evaporator operated under the same conditions as described above to deposit the Ag- And formed on a rod to prepare an optical filter.

[Experimental Example 1]

The transmission efficiency of the optical filter manufactured as in Example 1 was calculated using a commercially available FDTD solver (Lumerical). 2D simulations were performed to model the hybrid filter and measurement setup. A Gaussian beam with a lens shape of 0.8 NA was condensed onto the hybrid nano-rod and illuminated. The power transfer efficiency through the nanorod or Ag film was read by a power monitor located 500 nm below the Ag film and was used to generate a far-field distribution. In order to obtain the far field transmission to the objective lens in FIGS. 3 and 10, the collection efficiency was first calculated by dividing the far field distribution integrated on the collection cone in quartz into the far field distribution integrated from all angles. The ratio was then multiplied by the power transfer efficiency to yield the far field transmission. PML (perfectly matched layers) boundary conditions were used. The dielectric function for Ag can be found in Johnson and Christy, Johnson, P. B .; Christy, R. W. Optical Constants of Noble Metals. Phys Rev B 1972, 6, (12), 4370-4379], and the genetic function for ZnO is described in Adachi, Yoshikawa, H .; Adachi, S. Optical constants of ZnO. According to Jpn J Appl Phys 1 1997, 36, (10), 6237-6243, the dielectric function for Ge is described by Palik, Palik, E., Handbook of Optical Constants of Solids. Academic Press: New York, 1985].

In the study of any number of filter elements, plane wave excitation was used. Periodic boundary conditions were performed for infinite array calculations.

[Experimental Example 2]

A supercontinuum laser (Fianium, sc-400) was used as a white light source in order to measure the transmission of the optical filter manufactured in the same manner as in Example 1 above. The light from the infrared was removed using a short-pass filter (FF01-890 / SP-25, Semrock). The incident light was focused onto a single nano-rod filter through an 0.8 NA objective lens with a spot size of about 1 um to about 2 um in size. Transmitted light was collected by a separate 0.8 NA objective located behind the sample and detected by a spectrometer (Princeton Instrument SP2300i) using a 300 mm grid of 500 nm blazed grating equipped with a nitrogen-cooled CCD array. The Ag-coated NR was manually centered by observing the spatial image through the CCD. Integrated power over 400 nm to 700 nm was maintained at approximately 1 μW through the use of a neutral density filter. After measuring the transmission spectrum of the hybrid NR, the focus was shifted to the untreated bare area near the illuminated NR, where background transmission spectra were collected for standardization purposes.

result

3A shows a hybrid optical filter consisting of a single ZnO nanorod positioned between two layers of Ag films. ZnO is chosen because of its large band cap energy, so that visible light is efficiently localized through the real part of its dielectric function and loss is minimized through a small imaging part. Other large bandgap materials such as GaN could also be used, but ZnO was found to be a better material due to the smaller loss factor. The hybrid system may be a MOVPE process [Park, W. I .; Kim, D. H .; Jung, S. W .; Yi, G. C. Metalorganic vapor-phase epitaxial growth of vertically well-aligned ZnO nanoroads. Appl. Phys. Lett. 2002, 80, (22), 4232-4234] and an ultra-high purity ZnO nanorod having a diameter of 100 nm to 200 nm was formed on the Ag surface prepared on the top of the quartz substrate wetted with a Ge thin film First drop-cast. The Ge wetting layer was provided to reduce the roughness of the Ag film. As soon as the geometry of the ZnO nanorods was measured by SEM, a separate Ag layer was deposited on top of the ZnO nanorods to form a first Ag-layer. Here, the first and second Ag-layer thicknesses were numerically determined by finding the optimal combination to maximize the filtered transmission efficiency. A very thin layer of Ag with a total thickness less than the epidermal depth causes light leaking through the background while a thick layer prevents light from entering and exiting the nano rod (Figure 4) 1 &lt; / RTI &gt; and 15 &lt; RTI ID = 0.0 &gt; 5 &lt; / RTI &gt;

3B is an SEM image showing Ag-coated ZnO nanorods. Due to the upper half of the nano-rods enclosing the lower half from the metal evaporation source, the Ag-coating did not completely encapsulate the ZnO nanorods. However, the half-cavity enabled sufficient scattering cancellation and optical constraints to allow the incident light to be strongly resonant in the ZnO nanorods and transmitted through the second Ag layer. The performance of the hybrid device of this embodiment in the far field was measured using a spatially localized excitation using the setup as shown in Figure 3c. (400-700 nm), supplied by Fianium Inc. and polarized along the nano-rod axis, through an 0.8 NA objective lens producing an excitation spot size in the range of 1 [mu] m to 2 [ Lt; / RTI &gt; Polarization along the nanorod axes excludes the excitation of surface plasmons due to the lack of electric field components orthogonal to the Ag surface. The transmitted light was then collected through a separate 0.8 NA objective located behind the device and observed by a spectroscope.

The theoretical far field transmission efficiency resulting from the setup was predicted using a commercially available finite difference time domain (FDTD) solver (Lumerical, Inc). A 2D model was used to describe the 3D system. This simplification, due to the collapse of the incident Gaussian beam in two dimensions, provides a fast and sufficiently accurate approximation of the transmission characteristics, although the transmission strength is somewhat less extrapolated. Figure 3d shows the far field transmission efficiency as a function of wavelength and nominal core diameter. The plot demonstrated that transmission is both filtering and control over visible wavelengths as a function of core diameter. The transmission efficiencies produced and collected by the two 0.8 NA objectives reached values of 20% to 50%. These theoretical values do not include the contribution of the Ge layer and thus represent an upper bound on the achievable efficiency. Because of the strong absorption of Ge, a 1 nm thick Ge layer can actually reduce the maximum far field efficiency from 50% to almost 45% when using focused illumination and collection through a 0.8 NA objective (Fig. 4). In Figure 4, the untreated Ag layer is shown in black, and all calculations involve excitation and collection using two 0.8 NA objectives. Different Ag wetting materials, such as Al-doped Ag alloys, have been reported to exhibit negligible absorption in the visible range, which is an alternative route to achieving a smooth Ag film without sacrificing efficiency It suggests.

The role of the first Ag layer and the second Ag layer was further emphasized, as shown in Figure 5, when the underlying quartz power transmission was observed when one of the first and second layers was absent. In both cases, the filtering functionality was very poor or significantly reduced compared to when both layers were present, as can be seen in FIG. 3D. From this, it can be inferred that each Ag layer provides two main purposes for hybrid nano-rods to be possible as spatial and spectral filters. The first objective is to prevent light leakage through all bands of the Ag film except the hybrid nano-rods. Another goal is to create a spatial-localization filtering mechanism based on the generation of Mie resonance by forming an effective Ag-cavity surrounding the ZnO nanorods.

Considering a simplified model in the form of a core-shell ZnO-Ag cylinder extending infinitely in and out of the context of the present invention to analyze the operating mechanism of the optical filter according to this embodiment, the hybrid nano- Respectively. This model uses the Mie scattering theory to analytically address the problem and to achieve a more intuitive guideline to understand the interaction between light and hybrid nano-rods. A similar approach has been used to describe increased Raman signals in dielectric-coated Ge nanowires. FIG. 6A is a schematic view of the model, with the top view showing a ZnO cylinder surrounded by a 30 nm-thick Ag shell and the bottom view showing a ZnO cylinder with nothing coated. Light is incident at right angles to the nano-rod axis and polarized along the nano-rod axis.

As shown in Fig. 6B, the scattering cross-sections of the core-shell and uncoated cylinders over the range of core diameter and wavelength were analytically calculated. In both cases, it was found that scattering was controlled by the bipolar (m = 0) scattering mode in the desired wavelength and diameter range. In core-shell cylinders, scattering at specific diameters and wavelengths, shown as a dense band in the plot, was significantly reduced. These characteristics were similar to the transmission characteristics shown in Fig. 3d, but showed opposite patterns in strength. On the other hand, in uncoated cylinders, these bands were not found and the scattering section showed an increasing pattern for larger diameters. The contrast behavior between the uncoated cylinder and the core-shell cylinder suggests that the Ag-shell assist in reducing scattering at specific wavelengths and diameters so that the light is transmitted unhindered in the forward direction. This phenomenon is evident in the prior literature [Alu, A .;;;;;;;;;;;;;;;;;; Engheta, N. Achieving transparency with plasmonic and metamaterial coating s. Phys Rev. E 2005, 72, (1)]. Such schemes are described in the prior art [Fan, P. Y.; Chettiar, U. K .; Cao, L. Y .; Afshinmanesh, F .; Engheta, N .; Brongersma, M. L. An invisible metal-semiconductor photodetector. Nat Photonics 2012, 6, (6), 380-385. According to the preceding documents, reduced scattering in the hybrid ZnO nanorods has been found to be due to the presence of opposing dipoles in the Ag shell and ZnO core, which leads to increased transparency.

Corresponding explanation for increased permeation in hybrid devices could be found by evaluating the absorbing cross section of the core-shell cylinder. Figure 7 shows the analytically calculated absorption cross-sections of the core-shell and uncoated cylinders as a function of wavelength and diameter. It has been observed that the absorption resonance, also known as leaky-mode resonances, is significantly increased by the Ag shell and approximately the same pattern as the scattered valleys of Figure 6b. Figure 6c is a sharper view showing simultaneously the analytical scattering and absorption cross-sections of a core-shell and a non-coated cylinder from a 180 nm diameter core as a function of wavelength. In core-shell cylinders, scattering was observed to decrease when the absorption was at a peak near resonance at 590 nm, but this behavior did not occur in the case of solid cylinders.

Figure 6d shows the normalized angular distribution of scattered light at the absorption resonance. A comparison of angular scattering between core-shell and uncoated cylinders as shown in the top and bottom views shows that the presence of an Ag shell, respectively, is indeed aiding the scattered light to go forward. The limited backscattering at 180 degrees is a limitation due to incomplete offset of scattering. A close link between increased permeation and absorption is found in previous studies [Rodrigo, S. G .; Garcia-Vidal, F. J .; Martin-Moreno, L. Theory of absorption-induced transparency. Phys. Rev. B 2013, 88, 155126.] is similar to the behavior named absorption-induced transparency, which is observed in the dye-filled holes in the metal films theoretically confirmed. In the preceding document it has been demonstrated that the simultaneous peaks of absorption and transmission are caused by a reduction in evanescent light propagated through the dye-filled hole as a result of an alteration of the effective permittivity in the absorption resonance . Although the hybrid geometry according to this embodiment in Fig. 3A does not represent an absorber-filled hole as disclosed in the prior art, the mechanism is similar in that the transmission is peaked spatially from the absorption target and spectrally from its absorption resonance.

The basic mechanism for increased transmission in resonance through a simple core-shell model can be established to illustrate the filtering in an actual hybrid device according to this embodiment. To calculate the ratio of transmitted power through the Ag film, we injected a Gaussian beam generated through a 0.8 NA thin lens using the 2D technique of the model in Figure 3a. FIG. 8A shows the numerically simulated power transfer efficiency of a hybrid device including an Ag shell-ZnO core showing a nominal diameter (red curve) of 180 nm and a basic Ag film (black curve) constituting the background. A distinct peak was observed at 612 nm for the hybrid nano-rods, whereas only monotonic degradation was observed for the bare Ag film. FIG. 8B is a view of the real part of a pointing vector along the y-direction of the hybrid nano-rod and the basic Ag film at the selected wavelength indicated by the numbered arrows in FIG. 8A, respectively. For a basic Ag film, the bottom image showed that power could not be transmitted along the Ag film at all three wavelengths of interest.

When the ZnO nanorods were inserted between the two Ag layers, the power distribution varied considerably as can be seen in the top image of Figure 8b. In Figures 1 and 3 of the top image of Figure 8b, light could not penetrate effectively through the hybrid device. However, near the absorption resonance, as in the two figures of the upper image of Figure 8b, the nanorods are more transmissive than the background, so that light can flow out through the nanorods, Can be effectively transmitted. This transmission is mediated by confinement of the electric field in resonance, as shown in FIG. By observing the concentrated field distribution at the resonance, it was also confirmed that the mechanism was not controlled by localized surface plasmons because the field did not occur at the metal interface.

To determine the ability to filter light and the tunability of the filtered response, we measured the transmission through three hybrid nano-rods with distinct diameters corresponding to the output at the blue, green and red wavelengths. 10A shows SEM images of the three ZnO nanorods in order of decreasing nominal diameter from top to bottom. The images were taken before deposition of the second Ag layer for accurate measurement of the nominal diameter. The left images clearly show the difference in diameter from top to bottom as an enlarged scanned image of each nanorod, with the overall shape shown in the right image. While some nanorods exhibit non-uniformities in diameter along their length, optical properties are very noticeable by the band exhibiting the least change, as seen in the left image. The nanorods showed diameters of 186 nm, 156 nm, and 125 6 nm, respectively, from top to bottom. FIG. 10B is an optical microscope image of three of the hybrid nano-rods illuminated with polarized light along the nano-rod axis. In practice, each hybrid nano-rod transmitted at individual wavelengths, corresponding to red, green and blue outputs, from top to bottom, respectively. Figure 10c shows the transmission response at each nanorod measured and calculated by a measurement setup configured using the setup as shown in Figure 3c. Here we have shown the transmission through the hybrid device normalized by transmission through a neighboring basic Ag film. In all cases, peaks with values greater than unity were observed, confirming that the hybrid nanorods are more transmissive in their absorption resonance. In addition, an increase in the nominal diameter occurs at the red-displacement of the transmission peak, which is very consistent with the numerically simulated profile, as can be seen in the bottom graph of Figure 10c, The core diameter obtained, the Ag thickness and the Ge layer. Separate peak wavelengths were confirmed from the hybrid nano-rods having various diameters and the correspondence with the wavelength-diameter dispersion relationship extracted from the simulation as shown in Fig. 10D was observed to confirm the controllability of the transmission. Here, two sets of hybrid filters, each made to have a different Ag thickness, were plotted. The first set corresponded to the three measurement results shown in FIG. 10C. The second set represents the first Ag thickness below the target value resulting in the red-shifted peak wavelength, consistent with the expected and experimentally proven tendency in the wavelength-Ag thickness relationship as shown in Fig. Although the peak position follows the expected linear trend, the measured and predicted peak intensities were significantly different from each other as can be seen in Fig. 10C. This large difference is mostly due to the larger spot size of the condensed light used in the measurement. The condensed beam spot size in this embodiment is 1 to 2 占 퐉 which is 3 to 4 times larger than the Abbe diffraction limit (? 0.6? / NA) used in the model. This nearly 3 to 4 times increased spot size results in a 3 to 4 fold decrease in transmittance intensity and the extra difference in intensity between calculation and measurement is due to non-uniformity due to surface roughness of the nano rod axis and Ag Can be considered. In incident light polarized at right angles to the nano-rod axis, the visible color contrast was reduced at each nanorod as the peak position moved into the near-infrared regime (Figure 11). In addition, the present embodiment has analyzed the difference in diameter of the nanorods and proposed the possibility of coding different colors into a single element. Figure 10E shows a progressively very thin ZnO nanorod having a tip diameter of 40 nm and a base diameter of 169 6 nm. When covered with a second Ag layer, the device filtered the classification of colors according to its wavelength-diameter variance.

An important criterion for the successful completion of such a hybrid filter is the robustness of the central wavelength to manufacturing errors at the width and height of the nanorod. One way to reduce the sensitivity of the filter to such changes is to increase the slope of the wavelength-diameter dispersion relationship as shown in Fig. 10D. The smaller real part of the dielectric function allows an increase in the slope despite lower optical confinement, and can be achieved by doping the ZnO nanorod with Al or Ga.

In summary, this example demonstrates a simple design in which light can be filtered and tuned to wavelength using a single nano-sized element in the form of ZnO nanorods integrated with the Ag-cavity. The principle of transmission is derived from the ability of the Ag cavity to highly concentrate the light into the nanorod and generate strong absorption resonance, or equivalently, the reduction of scattered light by the Ag cavity. Ag coating is performed only on the top and bottom of the nano-rods and does not need to be coated uniformly concentrically around the nano-rods, so that restrictions on manufacturing can be relaxed and the on-chip platform Integration of the device can be facilitated. Furthermore, unlike the plasmon grating-type filter, which requires an increased number of periods to achieve maximum efficiency, the hybrid nano-rod does not depend on the number of elements for the lineshapes Respectively. This opens up myriad applications, such as the hybrid nano-rods, enabling ultimate-size optical filters to be realized, as well as nanoscale communications devices and the fabrication of ultra-high resolution pixel arrays.

[Experimental Example 3]

Using various materials as nanostructures, the dielectric constant and the size and thickness of the filter elements were calculated based on the results, and the results are shown in FIGS. 12A to 12C.

As a result of using nanowires including Si, InAs, and GaN as nanostructures, it can be seen that the wavelength can be changed according to the thickness of the nanowires. The operating wavelength range depends on the dielectric constant I also showed. In the operating wavelength range, the ε 'of the nanorod is positive, ε "is mild, and ε' of the first layer and the second layer are negative.

12A shows the transmission reaction of a hybrid nanostructure including a Si nanowire and a first Ag layer and a second Ag layer of 20 nm and 10 nm thickness, respectively. The area band was 700 nm to 1,100 nm and showed operation in the near infrared region. 12B shows the transmission reaction of the hybrid nanostructure including the InAs nanowire and the first Ag layer and the second Ag layer of 20 nm and 10 nm thickness, respectively. The zone zone showed an operation in the near infrared region with 700 nm to 1,200 nm. 12C shows the transmission reaction of a GaN nanowire and a hybrid nanostructure including a first Ag layer and a second Ag layer of 30 nm and 10 nm thickness, respectively. The area band was 400 nm to 800 nm and showed an operation in the visible range.

[Experimental Example 4]

The hybrid filter of this embodiment was manufactured as in the above embodiment. In addition, a modified hybrid bar-Ag filter including a nano-rod in the form of a nano bar having a rectangular cross-section was prepared for practical application of a more practical and practical pixel design. The modified hybrid bar-Ag filter can be achieved by sequential steps of lithography and evaporation. Initially we started with an Ag-coated transparent substrate (with a wetting layer in between). After coating with photoresist, lithography techniques were performed and ZnO could be e-beam evaporated under oxygen flow. After generating an array of ZnO nanova on an Ag / transparent substrate, the top layer of Ag was evaporated using thermal evaporation or e-beam evaporation. The hybrid NR-Ag filter was configured with a 170 nm diameter spaced apart by 500 nm. The modified hybrid bar-Ag filter was composed of a rectangular bar having a width of 180 nm and a height of 120 nm. In the hybrid ZnO-Ag filter of this example, the lower and upper Ag thicknesses were 15 nm and 30 nm, respectively.

All structures were excited by plane waves, but the structures according to this example were driven to an electric field polarized parallel to the nano rod axis.

13, the hybrid filter of this embodiment maintained the spectral purity of the filtered light even when the number of elements was reduced to one. This is in sharp contrast to the filters through the plasmonic design.

Figure 14 shows the maximum transmission intensity that can be achieved through the infinite array construction of elements in the three systems. It was observed that the transmission intensity and linearity attain almost 70%. .

As the number of elements decreased, the strength in the nanorod system decreased correspondingly. It can be seen that the hybrid nano-rods of this embodiment decouple the transmission intensity from the linearity according to the number of elements. In other words, the hybrid ZnO-Ag design of the present embodiment increases (reduces) the transmission strength by merely adding (removing) a larger number of elements without affecting the linearity. This capability is such that this design of this embodiment is substantially and interchangeable to any arbitrary spatial scale in the nanometer to macro range.

[Experimental Example 5]

The efficiency dependence of the grating period on the infinite array of hybrid filters illuminated by plane waves was investigated (Figure 15). The hybrid nanorods used included 170 nm diameter ZnO nanorods. The main objective of this study is to show that the spectral position of the transmission peak is held fixed as a function of periodicity and the absolute transmission can be controlled. As the grating period increased, the transmission strength decreased as expected because the nanorod coverage decreased (FIG. 15). This behavior is in contrast to the behavior in the plasmonic grating where the change in grating period changes the spectral position of the filtered response and there is no direct method of independently controlling the transmission efficiency. The grating period of the hybrid filter assembly provides a new degree of freedom in adjusting the transmission efficiency without affecting linear or spectral positions.

An important and substantial result of the non-plasmonic mechanism is the ability to filter light with good spectral purity at all arbitrary spatial scales ranging from nano to macro through the addition or removal of filter elements. Figure 16a shows this behavior for a hybrid nanorod of 170 nm diameter assembled with a regular grating with a pitch of 500 nm. The normalized transmission spectrum excited by a plane wave indicates that the linear and central wavelengths of the filtered response are held fixed, regardless of the number of elements included. Both infinite filters and single filters produced responses with similar linearity at the same wavelength. This aspect is particularly useful when constructing color pixels where high throughput of light is required for a micro-scale small size. In a typical color subpixel, approximately 100 to 200 elements can be installed in a horizontal dimension using a 500 nm pitch. Figure 16b shows simulated transmission from an array of substantially usable hybrid filters each of which has a rectangular cross section. The upper part of FIG. 16B suggests a practical design for such an aim, and can be assembled through lithography, development, ZnO evaporation under oxygen flow, and Ag evaporation techniques. The normalized transmission curves from a filter comprising ZnO nanobars with a width of 180 nm and a height of 120 nm spaced apart at intervals of 500 nm showed similar linear and spectral positions as in the case of the hybrid nano-rod filter. This feature is distinguished from the plasmonic grating, where the linearity is a function of the number of elements and the linearity collapses and widens when the number of elements is slightly reduced.

Another advantage of the hybrid filter assembly of this embodiment is that the spectral behavior and transmission efficiency in the infinite grating can be decoupled and both can be optimized independently of each other. The top view of Figure 16c simulates transmission through an infinite array of hybrid nano-rods 170 nm in size at different periods. Since the coverage of the hybrid filter increases as compared to the bare Ag background, the spectral position remains fixed while the transmission efficiency increases in a smaller period. The lower part of Figure 16c shows peak transmittance values plotted as a function of period, showing an increase in transmission from approximately 30% to approximately 600% in the 1 μm cycle to approximately 70% in the cycle. The colored portion in the lower view of Figure 16c is a band indicating that the spectral position is no longer held fixed by coupling between the basic cavity modes. It is noted that the maximum 70% theoretical efficiency is comparable to the theoretical efficiency from plasmonic-grating. Below about 600 nm, the filtered wavelength was larger than the period so that the hybrid filter assembly began to appear as an effective medium, which produced a red displacement of the spectral position (FIG. 17). Above the same period, the transmission can be adjusted without affecting the linear or the central wavelength, allowing a degree of freedom that is useful in filter design. Figure 17 is for a hybrid filter grating having a pitch that is lower than the operating wavelength and represents the limit of transmission control using periodicity. 17A shows simulated transmission from an infinite array of 170 nm-sized hybrid filters with periods less than or equal to 500 nm, observed for periodicity where the red displacement at the center wavelength decreases. 17B shows the electric field distributions from the unit cells at 400 nm, 300 nm and 200 nm periodicities from left to right. The fields are 600 nm, 610 nm corresponding to the wavelengths that cause maximum transmission respectively from left to right nm and 630 nm, respectively.

The actual color pixels represent high efficiency and require the transmission and filtering of plane wave light, and should also conform to standard sizes. For all practical purposes, this feat can be achieved by configuring many hybrid nano-rods into arrays of sizes corresponding to pixel sizes. A diagram showing a substantial pixel design is shown in FIG. 13B, where a nanobar behaves as a filtering element instead of a nanorod.

At a 15.4 inch display (horizontal: 13.1 inches, vertical: 8.2 inches) with a resolution of 1024 x 768, each pixel was thought to have horizontal and vertical dimensions of 322 μm and 273 μm. For RGB pixels, each color subpixel will have a horizontal dimension of ~ 107 μm. If we set our periodicity at 500 nm, we can install nearly 200 elements, which is enough to achieve a transmission upper limit close to ~ 70% (Figure 14). These values are the highest values reported to date for actual plasmonic filters, Xu [Xu, T .; Wu, Y. K .; Luo, X. G .; Guo, L. J. Plasmonic nanoresonators for high-resolution color filtering and spectral imaging. Nat Commun 2010, 1, 59] and the like.

[Experimental Example 6]

A multiple band filter in which a plurality of hybrid nanostructures having different diameters were arranged as shown in Fig.

18A shows a filter system capable of transmitting light in two bands. Figure 18b shows a filter system capable of transmitting light in three bands. Here, the cross-sectional shape of the nanorods constituting each unit filter element may include various shapes such as a rectangle, a rectangle, a circle, a triangle, and a cube. When the size of the structure is several times smaller than the wavelength of light, There is no. In this experiment, a nano rod having a rectangular cross section was used.

FIG. 19 is a calculation result derived based on the optical filter of FIG. 18A. Using two kinds of nano-rods, we can confirm that the transmission is possible in two bands corresponding to the diameter. Also, it is shown that the period can be adjusted equally to P = P 1 = P 2, and the near infrared ray transmission band can be adjusted by fixing D 1 and changing D 2.

FIG. 20 is a calculation result derived based on the system shown in FIG. 18A. In this example, D2 is fixed but it is possible to adjust the transmission band of the visible range while maintaining the extreme infrared transmission band unchanged by changing the period with D1. Thus, Figures 19 and 20 show that the ease of being able to independently and separately control the two transmission bands is embedded in the filter design.

FIG. 21A shows calculation results based on the combination of the three types of nano-rods shown in FIG. 18B. 21A shows the transmittance derived from a system where P1 = P2 = P3 = 475 nm and D1 = 100 nm, D2 = 160 nm, and D3 = 220 nm. It can be seen that the transmission appears in the band corresponding to the diameter of each nanorod. However, it is also confirmed that the transmittance is significantly lowered. This is because the number of nano rods of each kind is reduced in the same space as in Fig.

FIG. 21B shows the transmittance derived from a system where P1 = P2 = P3 = 600 nm and D1 = 160 nm, D2 = 180 nm and D3 = 200 nm. The smaller the difference in size between the nano-rods of each kind, the more the transmission bandwidths are overlapped. As a result, the larger transmission bandwidth is effectively obtained. Using such a 'sculpting technique' has the strong advantage of being able to design the desired transmission characteristics.

[Example 2]

Plural TiO ₂ Nanowire  Including an optical filter

22 is a photograph of a pixel formed by combining and arranging a plurality of nanowires having diameters different from each other and photographed by a light microscope. The pixel of FIG. 22 is implemented by the spatial values shown in Table 1 below.

<Table 1>

(Unit: nm)

The manufacturing process of the filter is as follows. Sequentially, 3 nm Ge and 20 nm Ag layers were formed on the quartz substrate using an electron beam deposition process, and TiO ₂ nanowires of the thickness specified at the top and 150 nm high were subjected to electron beam lithography, deposition, and lift-off processes . Finally, a 30 nm Ag layer was formed on the top to complete the final optical filter. The length of the nanowire (longitudinal direction) was fixed at 10 μm. As shown in the SEM image of FIG. 23, it was confirmed that a plurality of Ag-TiO ₂ composite nanowires were formed in each pixel. For the operation of the filter, the polarization direction of incident light was set to be the same as that of the nanowire. The photograph of FIG. 22 was obtained by using a light microscope having a halogen lamp as a light source.

In line 1 of FIG. 22, the correlation between the lateral thickness of the nanowire and the color to be filtered and the intensity between single and multiple nanowires can be confirmed.

(Row, column) = (1,1) in FIG. 22 is a result obtained by implementing a filter while increasing the lateral thickness of a single nanowire from 100 nm to 200 nm in units of 10 nm. It was confirmed that the color changed from blue to red as the thickness increased. However, it was confirmed that the intensity of light was slightly faint by passing through the nanowire having a thickness of several hundred nanometers.

(Row and column) = (1, 2) in FIG. 22 is a result obtained by implementing a filter while increasing the lateral thickness of a single nanowire from 100 nm to 300 nm in units of 20 nm. As the thickness increased, it was confirmed that the color changed from blue to red. However, it was confirmed that the intensity of light was slightly faint by passing through the nanowire having a thickness of several hundred nanometers.

In the case of (rows and columns) = (1, 3) in FIG. 22, one pixel includes six nanowires each having a period of 500 nm, and the thickness of the nanowires constituting each pixel is the same in the pixel, 100 nm to 200 nm in 10 nm increments. The number of nanowires included in each pixel is 6, which indicates that the intensity of the nanowires is higher than that of a single filter.

In the case of (row, column) = (1, 4) in FIG. 22, one pixel includes six nanowires each having a period of 500 nm, and the thickness of each nanowire constituting each pixel is the same within a pixel, nm to 300 nm in 20 nm increments. The number of nanowires included in each pixel was 6, indicating that the intensity was higher than that of a single filter. Further, by increasing the thickness up to 300 nm, a dark red color could be obtained.

The second row in FIG. 22 is a result of checking the filter function at a plurality of wavelengths, rather than one wavelength in one pixel. From the above results, it can be seen that color or customized multiple wavelength filters that can not be realized with a single wavelength can be obtained by combining composite nanowires having different thicknesses.

In the case of (rows and columns) = (2,1) and (2,2) in FIG. 22, the combinations of the thicknesses shown in Table 1 are repeated three times in each pixel. Specifically, the first pixel of (2,1) has nanowires of 100, 150, and 200 nm thicknesses repeated three times. It was found that the light of blue, green, and vermilion corresponding to each lateral thickness was filtered at one pixel at the same time.

In the case of (rows and columns) = (2,3) and (2,4) in FIG. 22, numerical values are the same as (2,1) and (2,2) in order to confirm the reproducibility of the multi-wavelength filter function. (2,1) and (2,3) are the same, and (2,2) and (2,4) show the same composite color.

The third row in FIG. 22 shows the result of checking the performance of the pixel according to the number of nanowires in the pixel.

In the case of (rows and columns) = (3,1), (3,2), (3,3) and (3,4) in FIG. 22, The result is that the wire is repeated 1, 3, 6, and 12 times in one pixel. The pixels are formed on the upper and lower sides, respectively, and the upper and lower pixels are designed in the same manner for the purpose of confirming the reproducibility. It was confirmed that the filter colors were the same regardless of the number of nanowires, and it was confirmed that the number of filters formed was larger than that of the single nanowire filter.

The fourth row in FIG. 22 is a result of proving that the wavelengths and periods to be filtered by correlating the periods of the nanowires having the same lateral thickness are weakly correlated with each other. This is a result contrasted with the conventional plasmonic filters, and shows the characteristics of the present invention well.

In the case of (rows and columns) = (4,1), (4,2), (4,3) and (4,4) in FIG. 22, the thickness of the nanowires forming each filter is 120, , And 240 nm, at 500, 600, and 700 nm cycles, respectively. It was confirmed that the color change was not large even when the cycle was changed.

It will be understood by those of ordinary skill in the art that the foregoing description of the embodiments is for illustrative purposes and that those skilled in the art can easily modify the invention without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be interpreted as being included in the scope of the present invention .

100: substrate
200: Wetting layer
300: Second layer
400: nanostructure
500: 1st layer

Claims (17)

A nanostructure disposed on a transparent substrate; And an array of hybrid nanostructures comprising at least a portion of the surface of the nanostructure and a first layer coated on a surface of the transparent substrate on which the nanostructure is not disposed,
Wherein the nanostructure comprises a material having a positive value of epsilon 'as a real part of a permittivity epsilon represented by the following formula 1 in a wavelength band in which the optical filter operates; Wherein the first layer comprises a material having a negative value of a real part ε 'of a dielectric constant ε expressed in the following equation 1 in a wavelength band in which the optical filter operates:
[Formula 1]
Dielectric constant ε = ε '+ iε ";
The value of? 'Which is the real part of the dielectric constant? Of the material forming the nanostructure and the value of?' Which is the real part of the dielectric constant? Of the material forming the first layer are different from each other, Which minimizes scattering of light by interference,
Optical filter.
The method according to claim 1,
Wherein the nanostructures included in each of the hybrid nanostructures operate as a multi-band filter that simultaneously transmits light of a plurality of wavelength bands by including the same or different diameters.
The method according to claim 1,
Wherein the nanostructures included in each of the hybrid nanostructures operate as a multi-band filter that simultaneously transmits light of a plurality of wavelength bands by including materials that are the same or different from each other.
The method according to claim 1,
Wherein the transmittance is adjusted by adjusting the number or arrangement interval of the hybrid nanostructures.
The method according to claim 1,
Wherein the arrangement and / or arrangement of the hybrid nanostructures is controlled to adjust the width and linehape of the transmission wavelength band.
The method according to claim 1,
Wherein the nanostructure further comprises a second layer formed on the lower portion of the first layer.
The method according to claim 1,
Wherein the operating wavelength band of the optical filter comprises a visible light range or an infrared range.
The method according to claim 1,
Wherein the nanostructure comprises a material having a bandgap greater than an operating wavelength band of the optical filter.
The method according to claim 1,
The nano-structure is C (diamond), Si, Ge , Sn, SiC, S 8, Se, Te, BN, BP, BAs, ZnO, ZnSe, ZnS, ZnTe, CuCl, Cu 2 S, PbSe, PbS, ObTe, InGaN, InN, InP, InAs, InSb, BaTiO ₂ , SnS, SnS ₂ , SnTe, B ₁₂ As ₂ , AlN, AlP, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, CdS, CdSe, CdTe, InGaP , BaTiO ₃ , PbSeTe, Tl ₂ SnTe ₅ , Tl ₂ GeTe ₅ , Bi ₂ Te ₃ , Cd ₃ P ₂ , Cd ₃ As ₂ , Cd ₃ Sb ₂ , ZnsP ₂ , Zn ₃ As ₂ , Zn ₃ Sb ₂ , TiO _{2, Cu 2 O, CuO,} UO 2, UO 3, Bi 2 O 3, SnO 2, SrTiO 3, LiNbO 3, La 2 CuO 4, PbI 2, MoS 2, VO 2, V 2 O 3, GaSe, Bi _{2 S 3, NiO, CuInSe 2} , Ag 2 S, FeS 2, Cu 2 ZnSnS 4, CuZnSbS, Cu 2 SnS 3, Si 1 - x Ge x, Si 1 - x Sn x, Al x Ga 1 - x As, _{In x Ga 1-x As,} In x Ga 1 -x P, Al x In 1 - x As, Al x In 1 - x Sb, GaAsN, GaAsP, GaAsSb, AlGaN, AlGaP, InGaN, InAsSb, InGaSb, AlGaInP, water selected from AlGaAsP, IGaAsP, InGaAsSb, InAsSbP, AlInAsP, AlGaAsN, InGaAsN, InAsAsN, GaAsSbN, GaInNAsSb, GaInAsSbP, CdZnTe, HgCdTe, HgZnTe, HgZnSe, and Cu (in, Ga) Se ₂ the group consisting of That is, the optical filter comprising a.
The method according to claim 1,
Wherein the first layer comprises one or more of Ag, Au, Pt, Al, Si, Ge, Cu, P-doped Si, B-doped Si, and P- doped Ge &Lt; / RTI &gt;
The method according to claim 1,
Wherein the first layer is made of TiN, InP, Si, Ge, ZnO, GaN, InGaN, InN, Cu, Ga-doped ZnO, and Si-doped GaN when the operating wavelength band of the optical filter includes an infrared range. Lt; RTI ID = 0.0 &gt; 1, &lt; / RTI &gt;
The method according to claim 1,
Wherein the nanostructure has a thickness smaller than an operating wavelength of the optical filter.
The method according to claim 1,
Wherein a transmission wavelength or a transmission wavelength region of the optical filter is controlled by a thickness of the nanostructure.
The method according to claim 6,
Further comprising a wetting layer formed on the bottom of the second layer.
The method according to claim 1,
Wherein the first layer is formed on at least a portion of the surface of the nanostructure that is not in contact with the substrate or on all surfaces that are not in contact with the substrate.
The method according to claim 1,
The polarization direction of the light incident on the optical filter is fixed in the same direction as the axis of the nanostructure so that interference between the dipole in the first layer formed by the incident light and the dipole in the nanostructure causes light Scattering is canceled out and the transmittance of the optical filter is increased.
17. The method according to any one of claims 1 to 16,
Wherein the optical filter is used for bio-imaging or optical communication.

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