Reflective focusing terahertz controller with variable number of foci

Abstract

The present invention discloses a reflective focusing terahertz controller with a variable number of focal points. The device includes a terahertz wave incident end, a reflected terahertz wave output end, and an array focuser. The array focuser consists of 24×24 unit structures arranged on a plane perpendicular to the terahertz wave input direction. The unit structures, from bottom to top, include a top square open circular metal plate, an upper-middle polyimide dielectric layer, a middle metal cross, a lower-middle polyimide dielectric layer, and a bottom metal plate. The middle metal cross is configured into eight different unit structures, namely, a first unit structure, a second unit structure, a third unit structure, a fourth unit structure, a fifth unit structure, a sixth unit structure, a seventh unit structure, and an eighth unit structure, depending on the rotation angle and arm span of the metal cross. The reflective focusing terahertz controller with a variable number of focal points of the present invention has the advantages of simple structure, easy fabrication, and an adjustable number of focal points, meeting the application requirements of terahertz wave communication multiplexing systems.

Description

Technical Field

[0001] The present invention relates to the technical field of terahertz wave applications, and in particular to a reflective focusing terahertz controller with a variable number of focal points. Background Art

[0002] Electromagnetic waves with frequencies between 0.1 THz and 10 THz are called terahertz waves. Terahertz waves lie between infrared and microwave radiation in the electromagnetic spectrum, sharing certain properties. Like infrared and microwave radiation, terahertz radiation propagates within the line of sight and is non-ionizing. Like microwave radiation, terahertz radiation can penetrate a wide range of non-conductive materials. Limited availability of effective terahertz sources and sensitive detectors has limited the development and utilization of electromagnetic waves in this frequency range. In the past two decades, with the advancement of ultrafast technology, broadband, stable pulsed terahertz wave sources have become a widely used technology. This has led to rapid development of terahertz technology and sparked a surge in research both domestically and internationally. This advancement has provided the technical foundation for its practical applications, resulting in a positive and far-reaching impact in fields such as communications, astronomy, medical imaging, nondestructive testing, and safety inspection. The development of terahertz technology relies on the complete control of terahertz waves. Only by controlling various parameters of terahertz waves, such as amplitude, phase, focus, and angular momentum, can the application of terahertz waves be realized under relatively ideal conditions. Terahertz focusing controllers are one of the effective methods for controlling the focus of terahertz waves.

[0003] The reflective-focusing terahertz controller with a variable number of focal points proposed in this invention regulates the two focal points of reflective focusing of terahertz waves. This device boasts a simple structure and ease of fabrication. It can generate two different focal positions for incident terahertz waves with different polarization states, meeting the application requirements of terahertz wave communication multiplexing systems. Summary of the Invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a reflective focusing terahertz controller with a variable number of focal points.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows:

[0006] A reflective focusing terahertz controller with a variable number of focal points is characterized by comprising a terahertz wave incident end, a reflected terahertz wave output end, and an array focuser. The array focuser consists of 24×24 unit structures arranged on a plane perpendicular to the terahertz wave input direction, wherein the unit structure comprises, from bottom to top, a top square open circular metal plate, a middle-upper polyimide dielectric layer, a middle metal cross, a middle-lower polyimide dielectric layer, and a bottom metal plate.

[0007] The metal cross in the middle layer is constructed into 8 different unit structures according to the rotation angle and arm span length of the metal cross, namely the first unit structure, the second unit structure, the third unit structure, the fourth unit structure, the fifth unit structure, the sixth unit structure, the seventh unit structure and the eighth unit structure.

[0008] The reflective focusing terahertz controller with a variable number of focal points is characterized in that the top metal structure of each unit structure is a metal circle hollowed out on a square metal plate, the radius of the circle is 69~71μm, the center of the circle coincides with the center of the square metal plate, the thickness of the metal plate is 0.8~1.2μm, the length and width are both 145~155μm, and the material is gold. The reflective focusing terahertz controller with a variable number of focal points is characterized in that the thickness of the intermediate layer metal cross is 0.8~1.2μm, the arm width is 19~20μm, and the material is gold. The reflective focusing terahertz controller with a variable number of focal points is characterized in that the length of the long side of the cross of the first unit structure of the intermediate layer metal cross is 145~148μm, the length of the short side of the cross is 100~102μm, and the long side of the cross is 145~148μm. x The length of the long side of the cross of the second unit structure is 115μm~118μm, the length of the short side of the cross is 98~99μm, and the long side of the cross is 0°. x The length of the long side of the cross of the third unit structure is 108μm~110μm, the length of the short side of the cross is 96~98μm, and the long side of the cross is 11.25°. x The length of the long side of the cross of the fourth unit structure is 105μm~106μm, the length of the short side of the cross is 94~97μm, and the long side of the cross is 22.5°. x The length of the long side of the cross of the fifth unit structure is 101μm~104μm, the length of the short side of the cross is 93~95μm, and the long side of the cross is 33.75°. x The length of the long side of the cross of the sixth unit structure is 100μm~103μm, the length of the short side of the cross is 90~92μm, and the long side of the cross is 45°. x The length of the long side of the cross of the seventh unit structure is 101μm~102μm, the length of the short side of the cross is 83~85μm, and the long side of the cross is 56.25°. x The length of the long side of the cross of the eighth unit structure is 97μm~99μm, the length of the short side of the cross is 26~30μm, and the long side of the cross is 67.5°. x The axis is 78.75°.

[0009] The reflective focusing terahertz controller with a variable number of focal points of the present invention has the characteristics of simple structure, easy production, adjustable number of focal points, etc., and meets the application requirements of terahertz wave communication multiplexing systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 Schematic diagram of the three-dimensional structure and unit structure of a reflective focusing terahertz controller with a variable number of focal points;

[0011] Figure 2 This is a side view of the structure of a reflective focusing terahertz controller unit with a variable number of focal points;

[0012] Figure 3 This is a distribution diagram of the structure of a reflective focusing terahertz controller unit with a variable number of focal points.

[0013] Figure 4 The energy distribution and normalized intensity of two focal spots on the XZ plane are shown at Z = 1200 μm directly above the reflective focusing terahertz controller with a variable number of focal spots under the incidence of left circularly polarized terahertz waves.

[0014] Figure 5 The two focus positions and their energy distribution on the XY plane are located at Z = 1200 μm directly above the reflective focusing terahertz controller with a variable number of focus points under the incidence of left circularly polarized terahertz waves.

[0015] Figure 6 The energy distribution and normalized intensity of two focal spots on the XZ plane are shown at Z = 1200 μm directly above the reflective focusing terahertz controller with a variable number of focal spots under the incidence of right circularly polarized terahertz waves.

[0016] Figure 7 The two focus positions and their energy distribution on the XY plane are shown at Z = 1200 μm directly above the reflective focusing terahertz controller with a variable number of focus points under the incidence of right circularly polarized terahertz waves.

[0017] Figure 8 This is a diagram showing the four focal positions and their energy distribution on the XY plane, located at Z = 1200 μm directly above a reflective focusing terahertz controller with a variable number of focal points, under incident linearly polarized terahertz waves.

[0018] Figure 9 Except Figure 3 Any unit structure distribution diagram other than ;

[0019] Figure 10 yes Figure 9Energy distribution diagram in the XZ plane of the structure under left-hand circularly polarized terahertz wave incidence, located at Z = 1200 μm directly above the reflective focusing terahertz controller with a variable number of focal points;

[0020] Figure 11 yes Figure 9 Energy distribution diagram in the XZ plane of the structure under the incidence of right circularly polarized terahertz wave, located at Z = 1200μm directly above the reflective focusing terahertz controller with a variable number of focal points. DETAILED DESCRIPTION

[0021] like Figure 1 As shown, a reflective focusing terahertz controller with a variable number of focal points includes a terahertz wave incident port 1, a reflected terahertz wave output port 2, and an array focuser 3. The array focuser 3 is composed of 24×24 unit structures 4 arranged on a plane perpendicular to the terahertz wave input direction. The unit structures 4, from bottom to top, include a top square open circular metal plate 5, an upper-middle polyimide dielectric layer 6, a middle metal cross 7, a lower-middle polyimide dielectric layer 8, and a bottom metal plate 9.

[0022] The metal cross 7 of the middle layer is constructed into 8 different unit structures according to the rotation angle and arm span length of the metal cross, namely the first unit structure A, the second unit structure B, the third unit structure C, the fourth unit structure D, the fifth unit structure E, the sixth unit structure F, the seventh unit structure G and the eighth unit structure H.

[0023] The top metal structure 5 of each unit structure is a metal circle hollowed out on a square metal plate with a radius of 69~71μm. The center of the circle coincides with the center of the square metal plate. The thickness of the metal plate is 0.8~1.2μm, and the length and width are both 145~155μm. The material is gold. The thickness of the intermediate layer metal cross 7 is 0.8~1.2μm, the arm width is 19~20μm, and the material is gold. The length of the long side of the cross of the first unit structure A of the intermediate layer metal cross 7 is 145~148μm, the length of the short side of the cross is 100~102μm, and the long side of the cross is 145~148μm. x The length of the long side of the cross of the second unit structure B is 115μm~118μm, the length of the short side of the cross is 98~99μm, and the long side of the cross is 0°. x The length of the long side of the cross of the third unit structure C is 108μm~110μm, the length of the short side of the cross is 96~98μm, and the long side of the cross is 11.25°. x The length of the long side of the cross of the fourth unit structure D is 105μm~106μm, the length of the short side of the cross is 94~97μm, and the long side of the cross is 22.5°. xThe length of the long side of the cross of the fifth unit structure E is 101μm~104μm, the length of the short side of the cross is 93~95μm, and the long side of the cross is 33.75°. x The length of the long side of the cross of the sixth unit structure F is 100μm~103μm, the length of the short side of the cross is 90~92μm, and the long side of the cross is 45°. x The length of the long side of the cross of the seventh unit structure G is 101μm~102μm, the length of the short side of the cross is 83~85μm, and the long side of the cross is 56.25°. x The length of the long side of the cross of the eighth unit structure H is 97μm~99μm, the length of the short side of the cross is 26~30μm, and the long side of the cross is 67.5°. x The axis is 78.75°.

[0024] Example 1

[0025] In this embodiment, the structure and shape of each part of a reflective focusing terahertz controller with a variable number of focal points are as described above, so they will not be described in detail. The array focuser 3 is composed of 24×24 unit structures. Figure 3 The specific parameters of each component are as follows:

[0026] The top metal structure 5 of each unit structure is a metal circle hollowed out on a square metal plate with a radius of 70μm. The center of the circle coincides with the center of the square metal plate. The thickness of the metal plate is 1.0μm, and the length and width are both 150μm. The material is gold. The thickness of the middle layer metal cross 7 is 1.0μm, the arm width is 20μm, and the material is gold. The length of the long side of the cross of the first unit structure A of the middle layer metal cross 7 is 145μm, the length of the short side of the cross is 100μm, and the long side of the cross is 150μm. x The length of the long side of the cross of the second unit structure B is 115μm, the length of the short side of the cross is 98.6μm, and the long side of the cross is 0°. x The length of the long side of the cross of the third unit structure C is 109.3 μm, the length of the short side of the cross is 97.8 μm, and the long side of the cross is 11.25°. x The length of the long side of the cross of the fourth unit structure D is 105.5 μm, the length of the short side of the cross is 96 μm, and the long side of the cross is 22.5°. x The length of the long side of the cross of the fifth unit structure E is 103.6 μm, the length of the short side of the cross is 94.1 μm, and the long side of the cross is 33.75°. x The length of the long side of the cross of the sixth unit structure F is 102.7 μm, the length of the short side of the cross is 91.2 μm, and the long side of the cross is 45°. xThe length of the long side of the cross of the seventh unit structure G is 101.5 μm, the length of the short side of the cross is 84 μm, and the long side of the cross is 56.25°. x The length of the long side of the cross of the eighth unit structure H is 98 μm, the length of the short side of the cross is 26 μm, and the long side of the cross is 67.5°. x The axis is 78.75°.

[0027] The terahertz wave signal is input from input port 1, and is output from the reflected terahertz wave output port 2 through the reflective focusing terahertz controller with a variable number of focal points. When a left circularly polarized terahertz wave is incident from input port 1, the terahertz wave with a frequency of 0.6 THz is reflected by the array focuser 3 and output from the reflected terahertz wave output port 2. Two focal points are formed at Z = 1200 μm directly above the array focuser 3. The focal points are located on both sides of the y-axis, and the distance between the two focal points is 1280 μm. Figure 4 shown. Figure 5 The figure shows the positions of two focal points and their energy distribution on the XY plane at Z = 1200 μm directly above the reflective focusing terahertz controller with a variable number of focal points under the incident left circularly polarized terahertz wave. When a right circularly polarized terahertz wave with a frequency of 0.6 THz is incident on the array focuser 3, the reflected terahertz wave is output from the reflected terahertz wave output terminal 2 and forms two focal points at Z = 1200 μm directly above the array focuser 3. The focal points are located on both sides of the x-axis and the distance between the two focal points is 1320 μm, as shown in the figure. Figure 6 shown. Figure 7 The figure shows the positions of two focal points and their energy distribution on the XY plane at Z = 1200 μm directly above the reflective focusing terahertz controller with a variable number of focal points under the incidence of right circularly polarized terahertz waves. When a linearly polarized terahertz wave with a frequency of 0.6 THz is incident on the array focuser 3, four focal points are formed on the XY plane at Z = 1200 μm directly above the array focuser 3, as shown in the figure below. Figure 8 shown.

[0028] From the above analysis, it can be seen that when a left circularly polarized terahertz wave is input into the structure of the designed reflective focusing terahertz controller with a variable number of focal points, two focal points are formed, located on both sides of the y-axis. When a right circularly polarized terahertz wave is input into the structure of the designed reflective focusing terahertz controller with a variable number of focal points, two focal points are formed, located on both sides of the x-axis. When a linearly polarized terahertz wave is input into the structure of the designed reflective focusing terahertz controller with a variable number of focal points, four focal points are formed on the XY plane. Therefore, the structure of the designed reflective focusing terahertz controller with a variable number of focal points achieves the adjustable number and position of the reflected terahertz wave focusing focal points under the incidence of terahertz waves with different polarizations.

[0029] Example 2

[0030] In this embodiment, the array focuser 3 is composed of 24×24 first unit structures A arranged in an array. Figure 9 shown.

[0031] The terahertz wave signal is input from the input terminal 1, and is output from the reflected terahertz wave output terminal 2 through the reflective focusing terahertz controller with a variable number of focal points. When the left circularly polarized terahertz wave is incident from the input terminal 1, the terahertz wave with a frequency of 0.6 THz is reflected by the array focuser 3 and output from the reflected terahertz wave output terminal 2. There is no focus at Z = 1200 μm directly above the array focuser 3, as shown in the figure. Figure 10 As shown in the figure, it shows that the reflected wave is not focused. When the right circularly polarized terahertz wave with a frequency of 0.6THz is incident on the array focuser 3, the reflected terahertz wave is output from the reflected terahertz wave output end 2, and there is no focus at Z=1200μm just above the array focuser 3, as shown in the figure. Figure 11 As shown, it shows that the reflected wave is not focused.

Claims

1. A reflective focusing terahertz controller with a variable number of focal points, characterized in that: The invention comprises a terahertz wave incident end (1), a reflected terahertz wave output end (2), and an array focuser (3); the array focuser (3) is composed of 24×24 unit structures (4) arranged on a plane perpendicular to the input direction of the terahertz wave; wherein the unit structure (4) comprises, from bottom to top, a top square open circular metal plate (5), a middle upper polyimide dielectric layer (6), a middle metal cross (7), a middle lower polyimide dielectric layer (8), and a bottom metal plate (9); The metal cross (7) in the middle layer is constructed into 8 different unit structures according to the different rotation angles and arm span lengths of the metal cross, namely, a first unit structure A, a second unit structure B, a third unit structure C, a fourth unit structure D, a fifth unit structure E, a sixth unit structure F, a seventh unit structure G and an eighth unit structure H; The length of the long side of the first unit structure A of the metal cross (7) of the intermediate layer is 145-148 μm, the length of the short side of the cross is 100-102 μm, and the long side of the cross is at 0° with the x-axis; the length of the long side of the second unit structure B is 115-118 μm, the length of the short side of the cross is 98-99 μm, and the long side of the cross is at 11.25° with the x-axis; the length of the long side of the third unit structure C is 108-110 μm, the length of the short side of the cross is 96-98 μm, and the long side of the cross is at 22.5° with the x-axis; the length of the long side of the fourth unit structure D is 105-106 μm, the length of the short side of the cross is 94-97 μm, and the long side of the cross is at 33.75° with the x-axis; the length of the long side of the fifth unit structure E is 101-104 μm, the length of the short side of the cross is 93- 95μm, the long side of the cross is 45° to the x-axis; the length of the long side of the cross of the sixth unit structure F is 100-103μm, the length of the short side of the cross is 90-92μm, and the long side of the cross is 56.25° to the x-axis; the length of the long side of the cross of the seventh unit structure G is 101-102μm, the length of the short side of the cross is 83-85μm, and the long side of the cross is 67.5° to the x-axis; the length of the long side of the cross of the eighth unit structure H is 97-99μm, the length of the short side of the cross is 26-30μm, and the long side of the cross is 78.75° to the x-axis; the first row of the intermediate layer metal crosses is arranged in the order of A, B, C, D, E, F, G, and H, and the first to seventh unit structures of the latter row are the same as the second to eighth unit structures of the previous row, and the eighth unit structure of the latter row is the same as the first unit structure of the previous row.

2. The reflective focusing terahertz controller with variable focal number according to claim 1, characterized in that: The square open circular metal plate (5) on the top layer of each unit structure is a metal circle hollowed out on the square metal plate, the radius of the circle is 67-73 μm, the center of the circle coincides with the center of the square metal plate, the thickness of the metal plate is 0.8-1.2 μm, the length and width are both 145-155 μm, and the material is gold.

3. The reflective focusing terahertz controller with variable focal number according to claim 1, characterized in that: The thickness of the metal cross (7) in the middle layer is 0.8-1.2 μm, the arm width is 19-20 μm, and the material is gold.

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