Metasurface Optical Switch Based on Tunable Structural Units

Abstract

The metasurface optical switch based on tunable structural units belongs to the field of micro-nano optoelectronic technology; the metasurface optical switch is formed by periodically arranging a plurality of tunable structural units, and each of the tunable structural units is composed of a base layer, an antenna and a rectangular block; the base layer is located at the lowermost end, the antenna and the rectangular block are arranged in the same plane and are located on the base layer; the shape of the base layer is square, the shape of the antenna is an equilateral triangular ring with an opening, the opening is located at the middle position of one side of the equilateral triangular ring, the rectangular block is located at the opening, and the centers of the square and the equilateral triangular ring coincide; the metasurface optical switch based on tunable structural units of the present invention has a simple structure, can perform switching modulation on optical signals of different wavelengths by changing the crystallization degree of the phase change material, and the highest extinction ratio can reach 10.1 dB.

Description

Technical Field

[0001] The metasurface optical switch based on tunable structural units of the present invention belongs to the field of micro-nano optoelectronic technologies. Background Art

[0002] A metasurface is an array structure composed of sub-wavelength antennas, which can modulate the phase, amplitude, and polarization of light. Due to the characteristics of small size and low loss compared with metamaterials, the metasurface has been applied in different photonic devices, such as absorbers, cloaking devices, special beam generators, holographic imaging, etc.

[0003] In high-speed optical communication systems, optical switches are used as key node devices to achieve functions such as optical cross-connection, optical switching, optical add-drop multiplexing, and network self-healing protection. At present, with the development of highly integrated optical switch devices, the requirements for characteristics such as electromagnetic interference resistance and fast response speed of optical switches are becoming more and more obvious. However, most existing optical switches are used to switch single-wavelength optical signals, the switching wavelength is not tunable, the structure is complex, and the extinction ratio is relatively low. It can be seen that it is particularly important to realize an optical switch with a tunable switching wavelength, a simple structure, and a high extinction ratio. Summary of the Invention

[0004] In order to achieve the above object, the present invention discloses a metasurface optical switch based on tunable structural units. The metasurface optical switch has a simple structure, can perform switching modulation on different-wavelength optical signals by changing the crystallization degree of the phase change material, and the highest extinction ratio can reach 10.1 dB.

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

[0006] The metasurface optical switch based on tunable structural units is formed by periodically arranging a plurality of tunable structural units. Each tunable structural unit is composed of a base layer, an antenna, and a rectangular block; the base layer is located at the lowermost end, the antenna and the rectangular block are arranged in the same plane and located on the base layer; the shape of the base layer is a square, the shape of the antenna is an equilateral triangular ring with an opening, the opening is located in the middle of one side of the equilateral triangular ring, the rectangular block is located at the opening, and the centers of the square and the equilateral triangular ring coincide.

[0007] The above-mentioned metasurface optical switch based on tunable structural units

[0008] The size of the base layer is 3 μm × 3 μm × 0.5 μm;

[0009] The height of the antenna is D1 = 0.5 μm, the outer ring side length of the equilateral triangular ring is L1 = 1.7370 - 2.0844 μm, and the inner ring side length L2 = 0.8685 μm;

[0010] The height of the rectangular block is D2 = 0.5 μm, the length is H = 2.7 μm, and the width is W = 0.3 - 0.5 μm.

[0011] Further, the following positional relationships of the base layer, the antenna, and the rectangular block are defined as the reference positions: the plane where the base layer is located is the XOY plane, two sets of opposite sides of the base layer are respectively parallel to the X-axis and the Y-axis, the opening of the equilateral triangular ring is parallel to the Y-axis, and the length direction of the rectangular block is parallel to the Y-axis. It is characterized in that the antenna and the rectangular block are both in the XOY plane. With the condition that the centers of the square and the equilateral triangular ring coincide, the included angle of the actual position relative to the reference position is θ = 0° - 90°.

[0012] Furthermore, incident X-direction linearly polarized light.

[0013] For the above-mentioned metasurface optical switch based on the tunable structural unit, the base layer is made of CaF2 material, the antenna is made of Si material, the rectangular block is made of GST phase change material, and the degree of crystallization of the phase change material is m = 0 - 1.

[0014] Beneficial effects:

[0015] First, the metasurface optical switch based on the tunable structural unit of the present invention only includes three components: the base layer, the open equilateral triangular ring antenna, and the rectangular block. Compared with other optical switches, it has the technical advantage of simple structure.

[0016] Second, the metasurface optical switch based on the tunable structural unit of the present invention can perform switch modulation on optical signals of different wavelengths by changing the degree of crystallization of the phase change material. Compared with other optical switches, it has the technical advantage of being tunable.

[0017] Third, the metasurface optical switch based on the tunable structural unit of the present invention can achieve an extinction ratio of 10.1 dB. Compared with other optical switches, it has the technical advantage of a high extinction ratio.

[0018] Fourth, the metasurface optical switch based on the tunable structural unit of the present invention, due to its simple structure, tunability, and high extinction ratio, can be applied to large-scale integrated optical communication devices in the future. Description of the Drawings

[0019] Figure 1 is a schematic structural diagram of the metasurface optical switch based on the tunable structural unit of the present invention.

[0020] Figure 2 is a schematic structural diagram of the tunable structural unit.

[0021] Figure 3 is a schematic diagram of the parameter definition of the tunable structural unit.

[0022] Figure 4 It is the reflectivity curve when the outer - ring side length L1 of the antenna changes.

[0023] Figure 5 It is the reflectivity curve when the width W of the rectangular block changes.

[0024] Figure 6 It is the reflectivity curve when the angle θ between the structural unit and the positive X - axis changes.

[0025] Figure 7 It is the reflectivity curve when the crystallization degree m of the phase - change material changes.

[0026] In the figure: 1 is the base layer, 2 is the antenna, and 3 is the rectangular block. Detailed implementation manners

[0027] The following further details the specific implementation manners of the present invention with reference to the accompanying drawings. Detailed implementation manner one

[0029] The following are the specific implementation manners of the metasurface optical switch based on the tunable structural unit of the present invention.

[0030] The metasurface optical switch based on the tunable structural unit under this specific implementation manner is formed by periodically arranging a plurality of tunable structural units, as Figure 1 shown; each of the tunable structural units is composed of a base layer 1, an antenna 2, and a rectangular block 3, as Figure 2 shown; the base layer 1 is located at the lowermost end, the antenna 2 and the rectangular block 3 are arranged in the same plane and are located on the base layer 1; the shape of the base layer 1 is a square, the shape of the antenna 2 is an equilateral triangular ring with an opening, the opening is located in the middle of one side of the equilateral triangular ring, the rectangular block 3 is located at the opening, and the centers of the square and the equilateral triangular ring coincide. Detailed implementation manner two

[0032] The following are the specific implementation manners of the metasurface optical switch based on the tunable structural unit of the present invention.

[0033] The metasurface optical switch based on the tunable structural unit under this specific implementation manner further limits each parameter on the basis of the first specific implementation manner, as Figure 3 shown:

[0034] The size of the base layer 1 is 3μm×3μm×0.5μm;

[0035] The height of the antenna 2 is D1 = 0.5μm, the outer - ring side length of the equilateral triangular ring is L1 = 1.7370 - 2.0844μm, and the inner - ring side length L2 = 0.8685μm;

[0036] The height of the rectangular block 3 is D2 = 0.5 μm, the length is H = 2.7 μm, and the width is W = 0.3 - 0.5 μm. Detailed Embodiment III

[0038] The following are the detailed embodiments of the metasurface optical switch based on the adjustable structural unit of the present invention.

[0039] For the metasurface optical switch based on the adjustable structural unit in this detailed embodiment, on the basis of Detailed Embodiment II, the parameters are further defined, such as Figure 3 Shown: Define the following positional relationship of the base layer 1, the antenna 2, and the rectangular block 3 as the reference position: The plane where the base layer 1 is located is the XOY plane. Two sets of opposite sides of the base layer 1 are respectively parallel to the X-axis and the Y-axis. The opening of the equilateral triangular ring is parallel to the Y-axis. The length direction of the rectangular block 3 is parallel to the Y-axis. The antenna 2 and the rectangular block 3 are both in the XOY plane. With the condition that the centers of the square and the equilateral triangular ring coincide, the included angle of the actual position relative to the reference position is θ = 0° - 90°. Detailed Embodiment IV

[0041] The following are the detailed embodiments of the metasurface optical switch based on the adjustable structural unit of the present invention.

[0042] For the metasurface optical switch based on the adjustable structural unit in this detailed embodiment, on the basis of Detailed Embodiment III, it is further defined that: incident X-direction linearly polarized light. Detailed Embodiment V

[0044] The following are the detailed embodiments of the metasurface optical switch based on the adjustable structural unit of the present invention.

[0045] For the metasurface optical switch based on the adjustable structural unit in this detailed embodiment, on the basis of Detailed Embodiment I, Detailed Embodiment II, Detailed Embodiment III, or Detailed Embodiment IV, it is further defined that: the base layer 1 is made of CaF2 material, the antenna 2 is made of Si material, the rectangular block 3 is made of GST phase change material, and the degree of crystallization of the phase change material is m = 0 - 1. Detailed Embodiment VI

[0047] The following are the detailed embodiments of the characteristic simulation of the metasurface optical switch based on the adjustable structural unit of the present invention.

[0048] For the metasurface optical switch based on the adjustable structural unit in this detailed embodiment, the outer ring side length L1 of the open equilateral triangular ring antenna 2 is simulated and tested. When the side length L1 changes from 1.7370 μm to 2.0844 μm, the situation of the reflectivity curve is as Figure 4As shown, it can be seen that as L1 increases, the resonance peak exhibits a blue shift, accompanied by a slight decrease in reflectivity, and the waveform remains basically unchanged. Specific Embodiment Seven

[0050] The following is a specific embodiment of the simulation of the characteristics of the metasurface optical switch based on the tunable structural unit of the present invention.

[0051] For the metasurface optical switch based on the tunable structural unit under this specific embodiment, the width W of the rectangular block 3 is simulated and tested. When the width W changes from 0.25 μm to 0.29 μm, the reflectivity curve is as follows Figure 5 As shown, it can be seen that as W increases, the resonance peak exhibits a red shift, accompanied by a slight increase in reflectivity. At the same time, the waveform remains basically unchanged. Specific Embodiment Eight

[0053] The following is a specific embodiment of the simulation of the characteristics of the metasurface optical switch based on the tunable structural unit of the present invention.

[0054] For the metasurface optical switch based on the tunable structural unit under this specific embodiment, the angle θ between the actual position and the reference position is simulated and tested. When the angle θ changes from 0° to 90°, the reflectivity curve is as follows Figure 6 As shown, it can be seen that as θ increases, the reflectivity of the resonance peak gradually increases, and the position and waveform of the resonance peak remain basically unchanged. When θ changes from 0° to 90°, the extinction ratio of the resonance peak reaches 10.1 dB. Specific Embodiment Nine

[0056] The following is a specific embodiment of the simulation of the characteristics of the metasurface optical switch based on the tunable structural unit of the present invention.

[0057] For the metasurface optical switch based on the tunable structural unit under this specific embodiment, the crystallization degree m of the phase change material is simulated and tested. When the crystallization degree changes from 0 to 1, the reflectivity curve is as follows Figure 7 As shown, it can be seen that as m increases, the resonance peak exhibits an obvious red shift, and the reflectivity and waveform remain basically unchanged; since the crystallization degree of the phase change material can be changed by changing the temperature of the structural unit, the switching wavelength can be tuned when the structural parameters of the tunable structural unit are fixed.

Claims

1. The metasurface optical switch based on tunable structural units is composed of a plurality of tunable structural units arranged periodically. Each tunable structural unit consists of a base layer (1), an antenna (2), and a rectangular block (3). The base layer (1) is located at the bottommost. The antenna (2) and the rectangular block (3) are arranged in the same plane and located on the base layer (1). The shape of the base layer (1) is square. It is characterized in that the shape of the antenna (2) is an equilateral triangular ring with an opening. The opening is located at the middle position of one side of the equilateral triangular ring. The rectangular block (3) is located at the opening. The centers of the square and the equilateral triangular ring coincide. The base layer (1) is made of CaF2 material, the antenna (2) is made of Si material, and the rectangular block (3) is made of GST phase change material.

2. The metasurface optical switch based on tunable structural units according to claim 1 It is characterized in that the size of the base layer (1) is 3μm×3μm×0.5μm; the height of the antenna (2) is D1 = 0.5μm, the outer ring side length of the equilateral triangular ring is L1 = 1.7370 - 2.0844μm, and the inner ring side length L2 = 0.8685μm; the height of the rectangular block (3) is D2 = 0.5μm, the length is H = 2.7μm, and the width is W = 0.3 - 0.5μm.

3. For the metasurface optical switch based on the adjustable structural unit according to claim 2, the following positional relationships of the base layer (1), the antenna (2), and the rectangular block (3) are defined as the reference positions: the plane where the base layer (1) is located is the XOY plane, two sets of opposite sides of the base layer (1) are respectively parallel to the X-axis and the Y-axis, the opening of the equilateral triangular ring is parallel to the Y-axis, and the length direction of the rectangular block (3) is parallel to the Y-axis. It is characterized in that, The antenna (2) and the rectangular block (3) are both in the XOY plane. With the condition that the centers of the square and the equilateral triangular ring coincide, the included angle of the actual position relative to the reference position is θ = 0° - 90°.

4. The metasurface optical switch based on the adjustable structural unit according to claim 3, wherein Incident X-direction linearly polarized light.

5. The metasurface optical switch based on adjustable structural units according to claim 1, 2, 3 or 4, characterized in that The degree of crystallization of the phase change material is m = 0 - 1.

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