Police handheld terahertz security check instrument based on direct data connection

Abstract

The invention discloses a police handheld terahertz security check instrument based on direct data connection. The security check instrument comprises a detector body and a handle fixedly connected with the detector body, the detector body comprises a shell, and a laser generator, a terahertz generation module, a terahertz detection module, a terahertz frequency conversion module and a terahertz signal transmission module which are arranged in the shell; the laser generator is arranged on one side of the terahertz generation module and irradiates the terahertz generation module; the terahertz generation module and the terahertz detection module are oppositely arranged at the two ends of the shell; the terahertz frequency conversion module is in communication connection with the terahertz detection module and the terahertz signal transmission module. The security check instrument communicates with external terminal equipment through the terahertz signal transmission module, and a data storage and processing module does not need to be arranged. In addition, the security inspection instrument can accurately detect contraband goods and dangerous goods such as drugs and explosives.

Description

Technical Field

[0001] The present invention relates to the technical field of public security inspection, and in particular to a police handheld terahertz security inspection instrument based on direct data connection. Background Art

[0002] Security checks in public places mainly use X-ray security inspection machines, metal detection gates and handheld metal detectors, but the above security inspection methods have great safety hazards. X-ray security inspection machines cannot detect people and have cumulative radiation damage to workers. Metal detection gates and handheld metal detectors, which are greatly affected by magnetic fields, often make false detections or miss detections and require secondary security checks. It is also difficult to detect non-metallic contraband such as ceramic knives and nail polish, and dangerous goods such as drugs and explosives. In addition, security inspectors are not sensitive to the sound and light alarm signals of X-ray security inspection machines, metal detection gates and handheld metal detectors in noisy environments, resulting in reduced security inspection accuracy and efficiency. In summary, existing security inspection equipment has defects such as radiation damage to the human body, a single detection type, and low security inspection accuracy and efficiency.

[0003] Terahertz waves refer to electromagnetic waves with frequencies between 0.1THz and 10THz. Terahertz waves have the characteristics of low energy, penetration, fingerprint spectrum, and broadband, which enable handheld terahertz security inspection devices to make up for the loopholes of existing security inspection equipment. First, the photon energy of terahertz waves is low, and there will be no radiation damage to the human body caused by photoionization, which makes up for the defects of X-ray security inspection machines that cannot detect personnel and cause radiation damage to workers. Secondly, terahertz waves can penetrate a variety of non-polar materials (including but not limited to cloth, leather, envelopes, plastics, and wood) and perform non-destructive testing on a variety of non-metallic contraband and dangerous goods, which makes up for the defects of metal detection doors and handheld metal detectors that cannot detect non-metallic contraband and dangerous goods. Thirdly, the spectrum of each substance in the terahertz band is unique like a human fingerprint. A variety of non-metallic contraband and dangerous goods have obvious characteristic absorption peaks in the terahertz band, which makes the detection sensitivity and security inspection accuracy of handheld terahertz security inspection devices higher. Finally, the terahertz wave has a fast transmission rate and a large transmission capacity, which enables the detection signal of the handheld terahertz security scanner to be wirelessly transmitted to the terminal device in real time through the 6G terahertz frequency band, greatly improving the detection efficiency of the handheld terahertz security scanner. Based on the above advantages of terahertz waves, the present invention proposes a police handheld terahertz security scanner based on direct data connection, which is safe for the human body, can detect a variety of contraband and dangerous goods without damage, and has high security inspection accuracy and efficiency.

[0004] The prior art with patent application number CN201822244692.0 discloses a portable terahertz security inspection device, in which the terahertz transmitting device is used to transmit the transmitting unit of the terahertz wave, and the terahertz detector is used to receive the terahertz wave reflected by the detected object. It integrates the storage module, the detection module, and the data processing module into the security inspection instrument, and its internal structure is complex, so that the handheld terahertz security inspection instrument cannot be chip-based and is expensive. The prior art with patent application number CN202022793337.6 discloses a handheld terahertz security inspection instrument, which includes a shell, a test module is arranged in the shell, and the test module includes a multi-channel terahertz detector, and the signal output end of the detector is connected to the signal input end of the A / D conversion unit. Its detection function is relatively single, and it cannot accurately detect dangerous goods such as drugs and explosives, resulting in incomplete detection functions. In summary, the many shortcomings of existing handheld terahertz security scanners prevent them from being widely used in various daily security inspections and security inspections in special places, which greatly limits the practical application of handheld terahertz security scanners in the public security field. Summary of the invention

[0005] The embodiment of the present application provides a police handheld terahertz security scanner based on direct data connection, aiming to solve the problems of complex structure and incomplete detection function of the handheld terahertz security scanner in the prior art method.

[0006] The embodiment of the present application provides a police handheld terahertz security detector based on data direct connection, the security detector comprising a detector body and a handle fixedly connected to the detector body;

[0007] The detector body includes a shell and a laser generator, a terahertz generation module, a terahertz detection module, a terahertz frequency conversion module and a terahertz signal transmission module arranged in the shell;

[0008] The laser generator is arranged on one side of the terahertz generating module and irradiates the terahertz generating module;

[0009] The terahertz generation module and the terahertz detection module are arranged at two ends of the housing opposite to each other;

[0010] The terahertz frequency conversion module is communicatively connected with the terahertz detection module and the terahertz signal transmission module respectively.

[0011] The embodiment of the present application provides a police handheld terahertz security detector based on direct data connection, which includes a detector body and a handle fixedly connected to the detector body; the detector body includes a shell and a laser generator, a terahertz generation module, a terahertz detection module, a terahertz frequency conversion module and a terahertz signal transmission module arranged in the shell; the laser generator is arranged on one side of the terahertz generation module and irradiates the terahertz generation module; the terahertz generation module and the terahertz detection module are arranged at two ends of the shell relative to each other; the terahertz frequency conversion module is respectively connected to the terahertz detection module and the terahertz signal transmission module for communication. The above-mentioned security detector communicates with the external terminal device through the terahertz signal transmission module, and there is no need to set up a data storage module and a data processing module, so that the security detector is more miniaturized and portable. In addition, the security detector in the present application can accurately detect contraband and dangerous goods such as drugs and explosives, and the detection function is very comprehensive, which is a function that the existing terahertz security detector cannot achieve. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0013] Figure 1 The overall structure diagram of the police handheld terahertz security inspection device based on direct data connection provided in the embodiment of the present application;

[0014] Figure 2 A partial structural diagram of a terahertz generation module of a police handheld terahertz security inspection device based on direct data connection provided in an embodiment of the present application;

[0015] Figure 3 A partial structural diagram of a terahertz detection module of a police handheld terahertz security inspection instrument based on direct data connection provided in an embodiment of the present application;

[0016] Figure 4 A partial structural diagram of a terahertz frequency conversion module of a police handheld terahertz security inspection device based on direct data connection provided in an embodiment of the present application;

[0017] Figure 5 A partial structural diagram of a terahertz signal transmission module of a police handheld terahertz security scanner based on direct data connection provided in an embodiment of the present application.

[0018] Figure numerals: 11, laser generator; 12, terahertz generation module; 13, terahertz detection module; 14, terahertz frequency conversion module; 15, terahertz signal transmission module; 20, handle; 10, detector body; 30, object to be tested; 121, Weyl semiconductor substrate; 122, MnBiTe layer; 123, ring electrode; 131, silicon wafer; 132, gold layer; 133, tellurium film; 134, hollow hole; 141, diamond substrate; 142, tellurium film layer; 143, strip electrode; 151, ellipsoidal reflector; 152, corrugated horn feed. DETAILED DESCRIPTION

[0019] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0021] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in the present specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes these combinations.

[0022] The present application embodiment discloses a police handheld terahertz security inspection instrument based on direct data connection, such as Figure 1As shown, the security scanner includes a detector body 10 and a handle 20 fixedly connected to the detector body 10; the detector body 10 includes a shell and a laser generator 11, a terahertz generation module 12, a terahertz detection module 13, a terahertz frequency conversion module 14 and a terahertz signal transmission module 15 arranged in the shell; the laser generator 11 is arranged on one side of the terahertz generation module 12 and irradiates the terahertz generation module 12; the terahertz generation module 12 and the terahertz detection module 13 are arranged at two ends of the shell opposite to each other; the terahertz frequency conversion module 14 is respectively communicated with the terahertz detection module 13 and the terahertz signal transmission module 15.

[0023] The security detector disclosed in the present application includes a detector body 10 and a handle 20, and the detector body 10 is fixedly connected to the handle 20. The detector body 10 mainly includes five parts: a laser generator 11, a terahertz generation module 12, a terahertz detection module 13, a terahertz frequency conversion module 14, and a terahertz signal transmission module 15. Among them, the femtosecond laser generated by the laser generator 11 is incident on the terahertz generation module 12 to generate a broadband terahertz wave, and the generated terahertz wave is emitted at 45 degrees to the object to be tested 30. After being reflected from the object to be tested 30, the terahertz wave carrying the information of the object to be tested 30 enters the terahertz detection module 13, and the terahertz wave coming out of the terahertz detection module 13 enters the terahertz frequency conversion module 14 to convert the frequency to 0.28THz. The terahertz wave after frequency conversion enters the terahertz signal transmission module 15 to radiate the terahertz wave of this band out of the security detector. The external terminal device receives the terahertz wave radiated by the security detector and analyzes it, thereby obtaining the detection information corresponding to the object to be detected 30 .

[0024] In a more specific embodiment, Figure 2 As shown, the terahertz generation module 12 includes a Weyl semiconductor substrate 121, a MnBiTe layer 122 and a plurality of pairs of annular electrodes; the MnBiTe layer 122 is flatly covered on the surface of the Weyl semiconductor substrate 121, and a plurality of pairs of annular electrodes 123 are arranged on the upper layer of the MnBiTe layer 122, and the two annular electrodes 123 included in each pair of annular electrodes are arranged opposite to each other. Specifically, the annular electrodes 123 are all arc-shaped, and the arc surfaces of the two annular electrodes 123 in each pair of annular electrodes are arranged opposite to each other. Among them, the spacing between the two annular electrodes 123 in each pair of annular electrodes is 3-8 microns.

[0025] like Figure 2As shown, the terahertz generating module 12 is composed of a photoconductive antenna, and the photoconductive antenna structure includes a Weyl semiconductor substrate 121, a MnBi Te layer 122 and a plurality of pairs of annular electrodes. The Weyl semiconductor substrate 121 can be prepared using tellurium (Te) element. Specifically, the preparation method of the terahertz generating module 12 includes: processing a 1 mm thick Weyl semiconductor tellurium substrate on a substrate by magnetron sputtering or vacuum evaporation, and then processing a 50 μm thick MnBi Te layer 122 by magnetron sputtering or vacuum evaporation, and then evaporating a plurality of pairs of annular electrodes thereon, and the spacing between the two annular electrodes 123 of each pair of annular electrodes is 3-8 microns. Preferably, the spacing between the two annular electrodes 123 of a pair of annular electrodes is 5 μm. In the specific application process, the annular electrodes 123 can be set to be arc-shaped, and the arc surfaces of the two annular electrodes 123 in each pair of annular electrodes are arranged relative to each other. The specific structure is as follows Figure 2 As shown, the terahertz generation module 12 provided in the specific application of the present application includes three pairs of ring electrodes.

[0026] In actual application, a bias voltage is applied to the two electrodes on the Weyl semiconductor substrate 121. Since the Weyl semiconductor substrate 121 has a semi-insulating property, a capacitor structure storing electrostatic potential is formed between the two electrodes; if a light pulse with a photon energy higher than the semiconductor energy gap is irradiated in the gap between the two electrodes at this time, free carriers will be instantly generated on the semiconductor surface in this area. These carriers accelerate under the bias voltage to form a current that varies with time, so that the stored electrostatic potential energy is released in the form of electromagnetic pulses. Broadband terahertz waves can be generated by passing a voltage of 10V to the terahertz generation module 12.

[0027] In a more specific embodiment, Figure 3 As shown, the terahertz detection module 13 includes a silicon wafer 131, a gold layer 132, a tellurium film 133 and a hollow hole matrix; the gold layer 132 covers the silicon wafer 131, the tellurium film 133 covers the gold layer 132, and the tellurium film 133 is provided with a hollow hole matrix; the hollow hole matrix is ​​composed of a plurality of hollow holes 134; the lateral spacing between the hollow holes 134 in each row of hollow holes increases from top to bottom. Among them, the lateral spacing between the hollow holes 134 in the first row of hollow holes is 10 microns, and the lateral spacing between the hollow holes 134 in the last row of hollow holes is 100 microns.

[0028] like Figure 3As shown, the terahertz detection module 13 is composed of a silicon wafer 131, a gold layer 132, a tellurium film 133 and a hollow hole matrix. Specifically, the preparation method of the terahertz detection module 13 includes: first processing a 50 μm gold layer 132 on the silicon wafer 131 by magnetron sputtering, then processing a 120 μm tellurium film 133, and processing a hollow hole matrix with a spacing of 10 μm to 100 μm on the tellurium film 133 by laser direct writing. The hollow hole matrix is ​​composed of a plurality of hollow holes 134, and the lateral spacing between the hollow holes 134 in each row of hollow holes increases from top to bottom. The specific structure is as follows: Figure 3 As shown. Among them, the lateral spacing between the hollow holes 134 in each row of hollow holes in the hollow hole matrix varies between 10μm and 100μm, and each row of hollow holes corresponds to a spacing, so the lateral spacing between the hollow holes 134 in the first row of hollow holes is 10 microns, and the lateral spacing between the hollow holes 134 in the last row of hollow holes is 100 microns. In the specific application process, each row of the hollow hole matrix can be set to contain 30 hollow holes 134, a total of 50 rows, and the diameter of each hollow hole 134 is 5μm; the lateral spacing of the hollow holes 134 is adjusted every five rows, and the lateral spacing of the hollow holes 134 in each row of the hollow hole matrix increases by 10μm. The terahertz detection module 13 is used to enhance the response to terahertz waves, wherein the gold layer 132 simultaneously acts as an electrode layer and a microcavity for reflecting terahertz waves, and the hollow hole matrix can produce a surface plasmon resonance effect. The gold layer 132 and the hollow hole matrix work together to enhance the detection performance of terahertz waves, especially broadband terahertz waves.

[0029] In a more specific embodiment, Figure 4 As shown, the terahertz frequency conversion module 14 includes a diamond substrate 141, a tellurium film layer 142 and a strip electrode 143; the tellurium film layer 142 is arranged on the diamond substrate 141, and a plurality of vertically arranged strip electrodes 143 are arranged in parallel on the tellurium film layer 142. The number of layers of the tellurium film layer 142 stacked on the diamond substrate 141 is less than 3. Specifically, the width of the strip electrode 143 is 0.08-0.12 mm and the length is 6-15 mm, and the strip electrode 143 is a gold metal strip electrode or a platinum metal strip electrode.

[0030] In specific application processes, such as Figure 4 As shown, the terahertz frequency conversion module 14 is manufactured using a single-layer tellurium film layer 142. Specifically, the preparation method of the terahertz frequency conversion module 14 includes: transferring a certain number of tellurium film layers 142 on a 0.3 mm thick diamond substrate 141, wherein the number of tellurium film layers 142 stacked on the diamond substrate 141 is less than 3 layers; then, evaporating a plurality of parallel-arranged strip electrodes 143 on the tellurium film layer 142, and the strip electrodes 143 are all arranged vertically.

[0031] In actual application, the width of the strip electrode 143 can be set to 0.08-0.12 mm and the length can be set to 6-15 mm; in a preferred embodiment, a strip electrode 143 with a width of 100 μm and a length of 1 cm can be set, and the spacing between two adjacent strip electrodes 143 is 50 μm. Further, the strip electrode 143 can be set to a gold metal strip electrode or a platinum metal strip electrode to increase the conversion effect of the terahertz wave. The terahertz frequency conversion module 14 can convert all terahertz signals into a frequency of 0.28 THz.

[0032] In a more specific embodiment, Figure 5 As shown, the terahertz signal transmission module 15 includes an ellipsoidal reflector 151 and a corrugated horn feed source 152 ; the corrugated horn feed source 152 is arranged on a side opposite to the reflection surface of the ellipsoidal reflector 151 .

[0033] In specific application processes, such as Figure 5 As shown, the terahertz signal transmission module 15 is composed of an ellipsoidal reflector 151 and a 280GHz corrugated horn feed 152. The corrugated horn feed 152 is arranged on the side opposite to the reflecting surface of the ellipsoidal reflector 151, and the corrugated horn feed 152 emits terahertz waves to the reflecting surface of the ellipsoidal reflector 151. The reflecting surface of the ellipsoidal reflector 151 reflects the terahertz waves so that the terahertz waves are radiated to the outside of the security scanner at a larger radiation angle, thereby improving the coverage area of ​​the terahertz waves radiated outward by the security scanner, so that the external terminal equipment can receive the terahertz waves radiated by the security scanner at different angles, thereby improving the application effect of the terahertz signal transmission module 15.

[0034] Optionally, the terahertz wave radiated by the terahertz signal transmission module 15 in the present application is transmitted to an external terminal device in real time using the 6G terahertz frequency band. The terminal device is equipped with a terahertz signal receiving module and a data processing module to transmit the detection information of whether the object to be tested 30 contains contraband and dangerous goods such as drugs and explosives to the police terminal and display it in real time. Optionally, the terahertz security inspection device proposed in the present application is integrated into the police law enforcement recorder to form a 6G sensory integrated law enforcement recorder, further improving the law enforcement efficiency of police officers.

[0035] The embodiment of the present application provides a police handheld terahertz security detector based on direct data connection, which includes a detector body and a handle fixedly connected to the detector body; the detector body includes a shell and a laser generator, a terahertz generation module, a terahertz detection module, a terahertz frequency conversion module and a terahertz signal transmission module arranged in the shell; the laser generator is arranged on one side of the terahertz generation module and irradiates the terahertz generation module; the terahertz generation module and the terahertz detection module are arranged at two ends of the shell relative to each other; the terahertz frequency conversion module is respectively connected to the terahertz detection module and the terahertz signal transmission module for communication. The above-mentioned security detector communicates with the external terminal device through the terahertz signal transmission module, and there is no need to set up a data storage module and a data processing module, so that the security detector is more miniaturized and portable. In addition, the security detector in the present application can accurately detect contraband and dangerous goods such as drugs and explosives, and the detection function is very comprehensive, which is a function that the existing terahertz security detector cannot achieve.

[0036] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A police handheld terahertz security inspection instrument based on direct data connection, characterized in that: The security detector comprises a detector body and a handle fixedly connected to the detector body; The detector body includes a shell and a laser generator, a terahertz generation module, a terahertz detection module, a terahertz frequency conversion module and a terahertz signal transmission module arranged in the shell; The laser generator is arranged on one side of the terahertz generating module and irradiates the terahertz generating module; The terahertz generation module and the terahertz detection module are arranged at two ends of the housing opposite to each other; The terahertz frequency conversion module is communicatively connected with the terahertz detection module and the terahertz signal transmission module respectively.

2. The police handheld terahertz security inspection device based on data direct connection according to claim 1 is characterized in that: The terahertz generation module includes a Weyl semiconductor substrate, a MnBiTe layer and a plurality of pairs of ring electrodes; The MnBiTe layer is flatly covered on the surface of the Weyl semiconductor substrate, and a plurality of pairs of the annular electrodes are arranged on the upper layer of the MnBiTe layer. Each pair of annular electrodes includes two annular electrodes that are arranged opposite to each other.

3. The police handheld terahertz security inspection instrument based on data direct connection according to claim 2 is characterized in that: The annular electrodes are all arc-shaped, and the arc surfaces of the two annular electrodes in each pair of annular electrodes are arranged opposite to each other.

4. The police handheld terahertz security inspection instrument based on direct data connection according to claim 3 is characterized in that: The distance between the two ring electrodes of each pair of ring electrodes is 3-8 microns.

5. The police handheld terahertz security inspection instrument based on data direct connection according to claim 1 is characterized in that: The terahertz detection module includes a silicon wafer, a gold layer, a tellurium film and a hollow hole matrix; The gold layer covers the silicon wafer, the tellurium film covers the gold layer, and a hollow hole matrix is ​​provided on the tellurium film; the hollow hole matrix consists of a plurality of hollow holes; and the lateral spacing between the hollow holes in each row of hollow holes increases from top to bottom.

6. The police handheld terahertz security inspection instrument based on direct data connection according to claim 5 is characterized in that: The lateral spacing between the hollow holes in the first row of hollow holes is 10 microns, and the lateral spacing between the hollow holes in the last row of hollow holes is 100 microns.

7. The police handheld terahertz security inspection instrument based on data direct connection according to claim 1 is characterized in that: The terahertz frequency conversion module comprises a diamond substrate, a tellurium film layer and strip electrodes; the tellurium film layer is arranged on the diamond substrate, and a plurality of vertically arranged strip electrodes are arranged in parallel on the tellurium film layer.

8. The police handheld terahertz security inspection device based on direct data connection according to claim 7 is characterized in that: The number of tellurium film layers stacked on the diamond substrate is less than 3 layers.

9. The police handheld terahertz security inspection instrument based on data direct connection according to claim 7 is characterized in that: The strip electrode has a width of 0.08-0.12 mm and a length of 6-15 mm, and is a gold metal strip electrode or a platinum metal strip electrode.

10. The police handheld terahertz security inspection device based on direct data connection according to claim 1 is characterized in that: The terahertz signal transmission module comprises an ellipsoidal reflector and a corrugated horn feed source; the corrugated horn feed source is arranged on a side opposite to the reflecting surface of the ellipsoidal reflector.

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