A terahertz wave generating device

Abstract

The present application relates to the technical field of terahertz, and especially relates to a terahertz wave generating device. The terahertz wave generating device comprises a laser source; an oscillation channel, the laser source is arranged towards the entrance of the oscillation channel, the oscillation channel comprises a hydrate layer, the inner wall of the hydrate layer is provided with an inner layer metal film, and the outer wall of the hydrate layer is provided with an outer layer metal film; and an output mirror group, the output mirror group comprises a converging concave mirror and a direction adjusting mirror, the converging concave mirror is arranged outside the oscillation channel, the concave surface of the converging concave mirror is arranged towards the oscillation channel, and the direction adjusting mirror is arranged corresponding to the converging concave mirror. After the laser is shot into the oscillation channel, a reciprocating oscillation reflection action is generated, further, high-intensity terahertz radiation is generated in the oscillation channel, and the converging concave mirror collects the terahertz wave and then adjusts the direction to output. The device not only has small volume and simple structure, but also can generate high-intensity terahertz wave.

Description

Technical Field

[0001] This invention relates to the field of terahertz technology, and more particularly to a terahertz wave generating device. Background Technology

[0002] Terahertz waves (THz waves), also known as terahertz rays (THz rays), were officially named in the mid-to-late 1980s; prior to that, scientists collectively referred to them as far-infrared rays. Terahertz waves are electromagnetic waves with frequencies ranging from 0.1 THz to 10 THz, and wavelengths ranging from approximately 0.03 mm to 3 mm, falling between microwaves and infrared waves. In recent decades, terahertz waves and related research fields have been a hot topic for scientists. Terahertz applications are extensive, demonstrating their immense value in areas ranging from military, security, and biomedical imaging to chemical research and space communication. Due to their unique non-ionizing properties, terahertz waves can easily penetrate several millimeters of biological tissue without causing damage.

[0003] Currently, terahertz sources are mainly generated through stimulated emission of free-electron lasers or through nonlinear photoconductivity and femtosecond rectification of electro-optic crystals. However, the terahertz radiation intensity generated by the optical rectification effect of lasers in nonlinear crystals is very low, mainly due to the low damage threshold of nonlinear crystals, making them highly susceptible to damage from lasers. Since the terahertz energy generated by current mainstream terahertz technologies is relatively low, it hinders the development of back-facing terahertz imaging technology. Therefore, designing a novel high-energy terahertz generator based on the needs of cutting-edge security applications has significant practical importance and application value. Summary of the Invention

[0004] This invention provides a terahertz wave generator to solve the problem of low terahertz radiation intensity generated by nonlinear crystals in the prior art.

[0005] To address the above problems, the present invention provides a terahertz wave generator, comprising:

[0006] Laser source;

[0007] An oscillation channel is provided, wherein the laser source is positioned toward the entrance of the oscillation channel, the oscillation channel includes a hydrate layer, an inner metal film is provided on the inner wall of the hydrate layer, and an outer metal film is provided on the outer wall of the hydrate layer;

[0008] An output mirror assembly includes a concave mirror and an adjusting mirror. The concave mirror is disposed outside the oscillation channel, with its concave surface facing the oscillation channel. The adjusting mirror is disposed corresponding to the concave mirror.

[0009] In one possible implementation, preferably, both the inner metal film and the outer metal film are made of gold or silver.

[0010] In one possible implementation, preferably, the output mirror assembly further includes an angle adjustment rod, one end of which is connected to the mounting carrier, and the other end of which is connected to the polymer concave mirror.

[0011] In one possible implementation, preferably, the output mirror assembly further includes an angle adjustment buckle disposed between the concave mirror and the angle adjustment rod, the angle adjustment buckle being used to adjust the angle of the concave mirror.

[0012] In one possible implementation, preferably, the laser source is a femtosecond pulsed laser source or a femtosecond ultrafast laser source.

[0013] In one possible implementation, preferably, the inner metal film is arranged in a mesh structure.

[0014] In one possible implementation, preferably, the hydrate layer comprises a colloidal medium.

[0015] The beneficial effects of this invention are as follows: This invention proposes a terahertz wave generating device, including a laser source; an oscillation channel, with the laser source positioned facing the entrance of the oscillation channel, the oscillation channel including a hydrate layer, an inner metal film disposed on the inner wall of the hydrate layer, and an outer metal film disposed on the outer wall of the hydrate layer; and an output mirror group, including a concave mirror and a directional mirror, the concave mirror being disposed outside the oscillation channel with its concave surface facing the oscillation channel, and the directional mirror being positioned corresponding to the concave mirror. This invention generates terahertz waves by enhancing the resonant field of the metal Fermi level. The laser oscillates at the metal Fermi level, enhancing the radiation of the terahertz waves while generating them. Furthermore, the device is small in size and has a simple structure. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the overall structure of the terahertz wave generator is shown.

[0018] Figure 2 A schematic diagram illustrating the operating principle when a laser is injected into an oscillating channel is shown.

[0019] Figure 3 It shows Figure 2 A magnified structural diagram of part A in the middle.

[0020] Explanation of key component symbols:

[0021] 100 - Laser source; 200 - Oscillation channel; 210 - Hydrate layer; 220 - Inner metal film; 230 - Outer metal film; 300 - Condensed mirror; 400 - Orientation mirror; 500 - Angle adjustment rod; 510 - Angle adjustment buckle; 600 - Light return device. Detailed Implementation

[0022] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0027] Please see Figure 1 , Figure 2 and Figure 3 The present invention provides a terahertz wave generating device (hereinafter referred to as the generating device), which includes a laser source 100, an oscillation channel 200 and an output mirror group (not shown in the figure), wherein the oscillation channel 200 is used to generate terahertz waves after laser oscillation, and the output mirror group is used to converge and output the generated terahertz waves.

[0028] Specifically, the oscillation channel 200 includes a hydrate layer 210, an inner metal film 220 is provided on the inner wall of the hydrate layer 210, and an outer metal film 230 is provided on the outer wall of the hydrate layer 210. At the same time, the laser source 100 is positioned toward the entrance of the oscillation channel 200.

[0029] The output mirror assembly includes a concave converging mirror 300, a directional mirror 400, and an angle adjustment rod 500. The concave converging mirror 300 is located outside the oscillation channel 200 and is used to converge the generated terahertz waves. At the same time, the directional mirror 400 is set to the reflection angle of the concave converging mirror 300 and is used to adjust the terahertz waves collected by the concave converging mirror 300 for output.

[0030] It should be explained that when the laser emitted by the laser source 100 enters the oscillation channel 200, it undergoes a reciprocating oscillation reflection within the oscillation channel 200. Furthermore, the laser generates enhanced terahertz waves through the interaction between the Fermi level of the metal film and the matter. This scheme is based on the ultrafast nonlinear four-wave mixing principle and combined with the material resonance two-level theory. It utilizes the enhancement of the resonant field of the metal Fermi level to generate terahertz waves. While the laser oscillates at the metal Fermi level, its radiation is enhanced, thereby generating high-intensity terahertz wave radiation. This device is small in size and simple in structure, effectively avoiding the shortcomings of traditional electro-optic crystal methods, such as the large size of carbon dioxide lasers and low photoelectric terahertz wave radiation.

[0031] It should be explained that the above scheme utilizes the evanescent wave principle combined with the Fermi level of the metal to generate terahertz waves through difference-frequency field enhancement. Due to the evanescent wave resonance enhancement effect and the adoption of new energy harvesting and reflection technologies, the obtained terahertz radiation is stronger and more directional, making this device more convenient and easier to implement as an active terahertz imaging technology, and easier to mass-produce in the field of public safety. The evanescent wave principle refers to the energy dissipation electromagnetic wave generated at the interface between two different media due to total internal reflection, also called an evanescent wave or decaying wave. Since its amplitude decreases exponentially with the increase of the depth perpendicular to the interface, and its phase changes with the tangential direction, it is also a surface wave.

[0032] The Fermi level of a metal refers to the outermost electron in a metal. Under the influence of Kelvin temperature, the Fermi level μ = 0.55 eV has a temperature range of 50 K ≤ T ≤ 375 K, according to the Fermi-Dirac statistics on Chinese Wikipedia.

[0033] The potential function energy range corresponding to the Fermi level in metals at room temperature (300 K) is 0.55 eV. This is slightly higher than the energy millieV of terahertz emission generated by covalently bonded materials.

[0034] For the interaction between matter to proceed in a certain way, stimulated radiation needs to reach a certain critical condition. Even working in a supercritical state requires special conditions.

[0035] In the above scheme, preferably, both the inner metal film 220 and the outer metal film 230 are made of gold material, but silver, copper and other materials can also be used.

[0036] Preferably, the output mirror assembly also includes an angle adjustment rod 500. One end of the angle adjustment rod 500 is used to connect to the mounting carrier, and the other end of the angle adjustment rod 500 is connected to the converging concave mirror 300. The angle adjustment rod 500 is used to adjust the convergence angle of the converging concave mirror 300, thereby matching the reflection angle of the directional mirror 400 to output the converged terahertz wave.

[0037] Preferably, the output mirror assembly also includes an angle adjustment buckle 510, which is a fine-tuning bolt structure. The angle adjustment buckle 510 is located between the concave mirror 300 and the angle adjustment rod 500. The angle adjustment buckle 510 is used to adjust the relative position between the concave mirror 300 and the angle adjustment rod 500. Of course, the fine-tuning bolt structure is a mature existing technology, so it will not be described in detail.

[0038] In the above scheme, preferably, the laser source 100 is a femtosecond pulse laser source or a femtosecond ultrafast laser source.

[0039] Please see Figure 2 and Figure 3Based on the above scheme, the inner metal film 220 is arranged in a mesh structure, and colloidal medium is distributed in the hydrate layer 210.

[0040] Please see Figure 2 Based on the above scheme, the generating device also includes a light reflection device 600, which is located at the end of the oscillation channel 200. When light is emitted from the oscillation channel 200, it can be reflected back into the oscillation channel 200, thereby enhancing the secondary utilization of light.

[0041] Preferably, the light retroreflector 600 can be a concave mirror, a concave lens, or a plane mirror, etc.

[0042] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A terahertz wave generator, characterized in that, include: Laser source; An oscillation channel is provided, wherein the laser source is positioned toward the entrance of the oscillation channel, the oscillation channel includes a hydrate layer, an inner metal film is provided on the inner wall of the hydrate layer, and an outer metal film is provided on the outer wall of the hydrate layer; An output mirror assembly includes a concave mirror and a directional mirror. The concave mirror is disposed on the side outside the oscillation channel, with its concave surface facing the oscillation channel. The directional mirror is disposed corresponding to the concave mirror.

2. The terahertz wave generator according to claim 1, characterized in that, Both the inner metal film and the outer metal film are made of gold or silver.

3. The terahertz wave generator according to claim 1, characterized in that, The output mirror assembly also includes an angle adjustment rod, one end of which is connected to the mounting carrier, and the other end of which is connected to the polymer concave mirror.

4. The terahertz wave generator according to claim 3, characterized in that, The output mirror assembly also includes an angle adjustment buckle, which is disposed between the concave mirror and the angle adjustment rod, and is used to adjust the angle of the concave mirror.

5. The terahertz wave generator according to claim 1, characterized in that, The laser source is a femtosecond pulse laser source or a femtosecond ultrafast laser source.

6. The terahertz wave generator according to claim 1, characterized in that, The inner metal film is arranged in a mesh structure.

7. The terahertz wave generator according to claim 1, characterized in that, The hydrate layer includes a colloidal medium.

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