Ultra-narrowband metasurface absorber

Abstract

The ultra-narrowband metasurface absorber of the present invention relates to the technical field of nano-scale metasurface absorbers; the ultra-narrowband metasurface absorber is composed of multiple arrays of identical cell units, and each cell unit is composed of a base layer, a dielectric layer, a bottom ring, a middle dielectric ring, a top ring, a bottom cuboid, a middle dielectric cuboid, and a top cuboid; the dielectric layer is closely attached above the base layer, and a structure composed of a bottom ring and a bottom cuboid is arranged on the dielectric layer; the middle dielectric ring and the top ring are successively covered on the bottom ring; the middle dielectric cuboid and the top cuboid are successively covered on the bottom cuboid; the ultra-narrowband metasurface absorber of the present invention has a simple structure, is easy to process even in the case of high integration, has a good absorption effect, a very narrow bandwidth of the transmission peak and better selectivity, and can transmit light in non-target wavelength bands almost perfectly.

Description

Technical Field

[0001] The ultra-narrowband metasurface absorber of the present invention relates to the technical field of nano-scale metasurface absorbers. Background Art

[0002] Surface plasmons are a special type of electromagnetic wave that propagates along metal-dielectric-metal due to the interaction between free-vibrating electrons and photons existing on the metal surface. The field strength is maximum at the metal surface and decays exponentially in the direction perpendicular to the interface, and it has the function of manipulating light.

[0003] Due to its very good selectivity, the metasurface narrowband absorber has become a very popular research topic in recent years. However, how to achieve narrowband high absorption in the near-infrared band is a difficult problem. Currently, in order to achieve narrowband high absorption in the near-infrared band, very complex structures often need to be designed, which is not conducive to processing and application. Then, designing an absorber with a simple structure and easy to process will be a development direction in this field. Summary of the Invention

[0004] In order to achieve the above object, the present invention designs an ultra-narrowband metasurface absorber, which has a simple structure, is easy to process even in the case of high integration, has a good absorption effect, the bandwidth of the transmission peak is very narrow and has better selectivity, and can almost perfectly transmit light in non-target bands.

[0005] The object of the present invention is achieved as follows:

[0006] The ultra-narrowband metasurface absorber is composed of multiple arrays of identical cell units. Each cell unit consists of a base layer, a dielectric layer, a bottom ring, a middle dielectric ring, a top ring, a bottom cuboid, a middle dielectric cuboid, and a top cuboid;

[0007] The dielectric layer is closely attached above the base layer, and a structure composed of a bottom ring and a bottom cuboid is arranged on the dielectric layer; the middle dielectric ring and the top ring are successively covered on the bottom ring; the middle dielectric cuboid and the top cuboid are successively covered on the bottom cuboid.

[0008] The above-mentioned ultra-narrowband metasurface absorber,

[0009] The structural parameters of the bottom ring, the middle dielectric ring, and the top ring are the same;

[0010] The structural parameters of the bottom cuboid, the middle dielectric cuboid, and the top cuboid are the same.

[0011] Furthermore,

[0012] In the base layer, the period Px in the x direction = 500 nm, the period Py in the y direction = 500 nm, and the height h1 = 100 nm;

[0013] In the dielectric layer, the period Px in the x direction is 500 nm, the period Py in the y direction is 500 nm, and the height h2 is 200 nm;

[0014] In the bottom ring, the middle dielectric ring, and the top ring, the outer diameter d1 is 100 nm, the inner diameter d2 is 20 nm, and the height h3 is 35 nm;

[0015] In the bottom cuboid, the middle dielectric cuboid, and the top cuboid, the width Wx in the x direction is 28 nm, the width Wy in the y direction is 200 nm, and the height h4 is 28 nm.

[0016] For the above ultra-narrowband metasurface absorber, the base layer is made of silicon material, the dielectric layer is made of silica material, the bottom ring is made of silver material, the middle dielectric ring is made of silica material, the top ring is made of silver material, the bottom cuboid is made of silver material, the middle dielectric cuboid is made of silica material, and the top cuboid is made of silver material.

[0017] Advantages:

[0018] First, the absorption layer of the ultra-narrowband metasurface absorber of the present invention is composed of multiple identical cell unit arrays, and each cell unit is only composed of eight structures: the base layer, the dielectric layer, the bottom ring, the middle dielectric ring, the top ring, the bottom cuboid, the middle dielectric cuboid, and the top cuboid. Therefore, it has the technical advantage of simple structure;

[0019] Second, the ultra-narrowband metasurface absorber of the present invention only uses three materials: silicon, silica, and silver. Since these materials are common materials in life and have low costs, the present invention has superior cost advantages; in addition, the processing technologies of these materials are very mature, which also enables the present invention to be easily processed under high integration.

[0020] Third, the absorption layer of the ultra-narrowband metasurface absorber of the present invention is composed of three layers of ring bodies (the bottom ring, the middle dielectric ring, and the top ring) and three layers of cuboids (the bottom cuboid, the middle dielectric cuboid, and the top cuboid). Compared with the single-layer structure, this three-layer structure has better absorption effect because it just meets the propagation condition of surface plasmons along metal-dielectric-metal.

[0021] Fourth, through simulation experiments, it can be known that the ultra-narrowband metasurface absorber of the present invention has a very narrow bandwidth of the transmission peak and better selectivity, and the light in the non-target wavelength band can be almost perfectly transmitted. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the ultra-narrowband metasurface absorber of the present invention.

[0023] Figure 2 It is a schematic structural diagram of each cell unit of the ultra-narrowband metasurface absorber of the present invention.

[0024] Figure 3 It is a schematic diagram of parameter definitions of each cell unit of the ultra-narrowband metasurface absorber of the present invention.

[0025] Figure 4 The transmittance curve obtained by changing the width Wx in the x direction.

[0026] Figure 5 The transmittance curve obtained by changing the width Wy in the y direction.

[0027] Figure 6 The transmittance curve obtained by changing the period Px in the x direction.

[0028] Figure 7 The transmittance curve obtained by changing the period Py in the y direction.

[0029] In the figure: 1 substrate layer, 2 dielectric layer, 3 bottom ring, 4 middle dielectric ring, 5 top ring, 6 bottom cuboid, 7 middle dielectric cuboid, 8 top cuboid. Detailed implementation manners

[0030] The following further details the specific implementation manners of the present invention with reference to the accompanying drawings. Detailed implementation manner one

[0032] The ultra-narrowband metasurface absorber under this specific implementation manner has a schematic structural diagram as Figure 1 shown, and is composed of an array of multiple identical cell units. The schematic structural diagram of each cell unit is as Figure 2 shown, and is composed of a substrate layer 1, a dielectric layer 2, a bottom ring 3, a middle dielectric ring 4, a top ring 5, a bottom cuboid 6, a middle dielectric cuboid 7, and a top cuboid 8;

[0033] The dielectric layer 2 is closely attached above the substrate layer 1, and a structure composed of the bottom ring 3 and the bottom cuboid 6 is arranged on the dielectric layer 2; the middle dielectric ring 4 and the top ring 5 are sequentially covered on the bottom ring 3; the middle dielectric cuboid 7 and the top cuboid 8 are sequentially covered on the bottom cuboid 6;

[0034] Among them, the substrate layer 1 is made of silicon material, the dielectric layer 2 is made of silicon dioxide material, the bottom ring 3 is made of silver material, the middle dielectric ring 4 is made of silicon dioxide material, the top ring 5 is made of silver material, the bottom cuboid 6 is made of silver material, the middle dielectric cuboid 7 is made of silicon dioxide material, and the top cuboid 8 is made of silver material;

[0035] Among them, the structural parameters of the bottom ring 3, the middle-layer dielectric ring 4, and the top ring 5 are the same; the structural parameters of the bottom cuboid 7, the middle-layer dielectric cuboid 7, and the top cuboid 8 are the same. The schematic diagram of parameter definition is as shown in Figure 3 as follows:

[0036] In the base layer 1, the period Px in the x direction = 500 nm, the period Py in the y direction = 500 nm, and the height h1 = 100 nm;

[0037] In the dielectric layer 2, the period Px in the x direction = 500 nm, the period Py in the y direction = 500 nm, and the height h2 = 200 nm;

[0038] In the bottom ring 3, the middle-layer dielectric ring 4, and the top ring 5, the outer circle diameter d1 = 100 nm, the inner circle diameter d2 = 20 nm, and the height h3 = 35 nm;

[0039] In the bottom cuboid 6, the middle-layer dielectric cuboid 7, and the top cuboid 8, the width Wx in the x direction = 28 nm, the width Wy in the y direction = 200 nm, and the height h4 = 28 nm. Specific Embodiment 2

[0041] For the ultra-narrowband metasurface absorber under this specific embodiment, the performance of the bottom cuboid 6, the middle-layer dielectric cuboid 7, and the top cuboid 8 under different parameters is simulated.

[0042] Among them, the light source is incident in the direction from the top cuboid 8, the middle-layer dielectric cuboid 7 to the bottom cuboid 6, and FDTD is used for simulation. The simulation results are as follows:

[0043] Simulation Experiment 1: Keep h1 = 100 nm, h2 = 200 nm, h3 = 35 nm, h4 = 35 nm, d1 = 100 nm, d2 = 20 nm, Wy = 200 nm, Px = 500 nm, Py = 500 nm unchanged. The width Wx in the x direction of the bottom cuboid 6, the middle-layer dielectric cuboid 7, and the top cuboid 8 is increased from 24 nm to 28 nm in steps of 2 nm. The obtained transmittance curve is as shown in Figure 4 It can be seen that as Wx increases, the transmission peak undergoes an obvious red shift.

[0044] Simulation Experiment 2: Keep h1 = 100 nm, h2 = 200 nm, h3 = 35 nm, h4 = 35 nm, d1 = 100 nm, d2 = 20 nm, Wx = 28 nm, Px = 500 nm, Py = 500 nm unchanged. The width Wy in the y direction of the bottom cuboid 6, the middle-layer dielectric cuboid 7, and the top cuboid 8 is increased from 200 nm to 240 nm in steps of 20 nm. The obtained transmittance curve is as shown in Figure 5As shown, it can be seen that as Wy increases, the transmission peak exhibits an obvious red shift.

[0045] Up to this point, when fabricating the ultra-narrowband metasurface absorber, Wx = 28 nm and Wy = 200 nm are selected. Specific Embodiment Three

[0047] For the ultra-narrowband metasurface absorber under this specific embodiment, the performance of the base layer 1 and the dielectric layer 2 under different parameters is simulated.

[0048] Among them, the light source is incident in the direction from the top cuboid 8, the middle dielectric cuboid 7 to the bottom cuboid 6, and FDTD is used for simulation. The simulation results are as follows:

[0049] Simulation Experiment Three: Keeping h1 = 100 nm, h2 = 200 nm, h3 = 35 nm, h4 = 35 nm, d1 = 100 nm, d2 = 20 nm, Wx = 28 nm, and Wy = 200 nm unchanged, the period Px in the x-direction of the base layer 1 and the dielectric layer 2 is increased from 480 nm to 500 nm in steps of 10 nm. The obtained transmittance curve is as Figure 6 shown. It can be seen that as Px increases, the transmission peak exhibits an obvious red shift.

[0050] Simulation Experiment Four: Keeping h1 = 100 nm, h2 = 200 nm, h3 = 35 nm, h4 = 35 nm, d1 = 100 nm, d2 = 20 nm, Wx = 28 nm, and Wy = 200 nm unchanged, the period Py in the y-direction of the base layer 1 and the dielectric layer 2 is increased from 480 nm to 500 nm in steps of 10 nm. The obtained transmittance curve is as Figure 7 shown. It can be seen that as Py increases, the transmission peak exhibits an obvious red shift.

[0051] Up to this point, when fabricating the ultra-narrowband metasurface absorber, Px = Py = 500 nm is selected.

Claims

1. Ultra-narrowband metasurface absorber, which is composed of multiple arrays of identical cell units, and is characterized in that, Each cell unit is composed of a base layer (1), a dielectric layer (2), a bottom ring (3), a middle dielectric ring (4), a top ring (5), a bottom cuboid (6), a middle dielectric cuboid (7), and a top cuboid (8); The dielectric layer (2) is closely attached above the base layer (1), and a structure composed of the bottom ring (3) and the bottom cuboid (6) is arranged on the dielectric layer (2); the middle dielectric ring (4) and the top ring (5) are successively covered on the bottom ring (3); the middle dielectric cuboid (7) and the top cuboid (8) are successively covered on the bottom cuboid (6); The structural parameters of the bottom ring (3), the middle dielectric ring (4), and the top ring (5) are the same; The structural parameters of the bottom cuboid (6), the middle dielectric cuboid (7), and the top cuboid (8) are the same; In the base layer (1), the period Px in the x direction = 500 nm, the period Py in the y direction = 500 nm, and the height h1 = 100 nm; In the dielectric layer (2), the period Px in the x direction = 500 nm, the period Py in the y direction = 500 nm, and the height h2 = 200 nm; In the bottom ring (3), the middle dielectric ring (4), and the top ring (5), the outer diameter d1 = 100 nm, the inner diameter d2 = 20 nm, and the height h3 = 35 nm; In the bottom cuboid (6), the middle dielectric cuboid (7), and the top cuboid (8), the width Wx in the x direction = 28 nm, the width Wy in the y direction = 200 nm, and the height h4 = 28 nm; The base layer (1) is made of silicon material, the dielectric layer (2) is made of silicon dioxide material, the bottom ring (3) is made of silver material, the middle dielectric ring (4) is made of silicon dioxide material, the top ring (5) is made of silver material, the bottom cuboid (6) is made of silver material, the middle dielectric cuboid (7) is made of silicon dioxide material, and the top cuboid (8) is made of silver material.

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