Terahertz imaging system

Abstract

The utility model discloses a terahertz imaging system, which comprises the components of a bearing device which comprises a rotation driving mechanism and an objective table which is connected with a rotating end of the rotation driving mechanism, and the surface of the objective table is used for bearing a tested sample; the detection device comprises a terahertz emission mechanism, a transmission light path mechanism, a reflection light path acquisition detector and a transmission light path acquisition detector; the linear driving device comprises a linear driving mechanism and a sliding seat which are connected with each other, the linear driving mechanism is used for driving the sliding seat to do relative linear motion, and the bearing device or the detection device is mounted on the sliding seat. According to the terahertz imaging system, the scanning speed can be improved, synchronous acquisition of transmission and reflection images of the tested sample is realized, the structure of the imaging system is simplified, and the manufacturing cost of the imaging system is reduced.

Description

Technical Field

[0001] The utility model belongs to the field of semiconductor optoelectronic device applications, and particularly relates to a terahertz imaging system. Background Art

[0002] Terahertz waves are in the frequency band between millimeter waves and infrared light in the electromagnetic spectrum, with wavelengths between 0.1 mm and 1 mm. Terahertz imaging technology mainly utilizes the transmission, reflection, and absorption characteristics of terahertz waves in dielectric materials and can be used for non-destructive testing in fields such as medicine, security detection, and material detection. Since terahertz waves operate within the non-ionizing radiation range and have low energy, they have received extensive attention in biomedical and materials science. However, current terahertz imaging technology still has some limitations in terms of imaging speed, resolution, complexity, and cost.

[0003] Traditional terahertz imaging systems use point scanning or line scanning methods, that is, moving the object to be measured or moving the terahertz wave source and detector to scan the entire area to be measured, then collecting the reflected or transmitted terahertz signals and processing them on a computer to generate an image. However, these existing implementation schemes generally have some defects, such as slow imaging speed, high system complexity, low resolution, and high cost.

[0004] To improve the imaging speed, various schemes have been proposed, one of which is to use a turntable scanning method. In the turntable scanning method, the terahertz wave source and detector are installed on a turntable. When the turntable rotates, the terahertz waves emitted by the terahertz wave source are scanned onto the object to be measured by the turntable, and the terahertz waves reflected by the object to be measured are received by the detector. However, the rotation speed of the turntable is slow, resulting in a low imaging speed.

[0005] The information disclosed in this background art section is only intended to enhance the overall understanding of the utility model and should not be regarded as an admission or any form of suggestion that this information constitutes prior art already known to those of ordinary skill in the art. Summary of the Utility Model

[0006] The purpose of the utility model is to provide a terahertz imaging system that can improve the scanning speed, synchronously collect the transmission and reflection images of the sample to be measured, simplify the structure of the imaging system, and reduce the manufacturing cost of the imaging system.

[0007] To achieve the above purpose, a terahertz imaging system provided by a specific embodiment of the utility model includes:

[0008] A carrying device, including a rotation driving mechanism and a stage connected to the rotation end of the rotation driving mechanism, the surface of the stage being used to carry the sample to be measured;

[0009] The detection device includes a terahertz emission mechanism, a transmission optical path mechanism, a reflected optical path acquisition detector, and a transmitted optical path acquisition detector. The transmission optical path mechanism is used to transmit the terahertz wave emitted by the terahertz emission mechanism to the sample to be measured on the surface of the stage, and reflect the terahertz wave reflected by the sample to the reflected optical path acquisition detector and converge the terahertz wave transmitted through the sample to the transmitted optical path acquisition detector;

[0010] The linear driving device includes a connected linear driving mechanism and a sliding seat. The linear driving mechanism is used to drive the sliding seat to perform a relative linear motion, and the carrying device or the detection device is installed on the sliding seat.

[0011] In one or more embodiments of the present invention, the transmission optical path mechanism includes a first off-axis parabolic mirror and a second off-axis parabolic mirror;

[0012] The first off-axis parabolic mirror is located on the optical path of the light beam emitted by the terahertz emission mechanism, and is used to collimate and reflect the light beam emitted by the terahertz emission mechanism to the second off-axis parabolic mirror;

[0013] The second off-axis parabolic mirror is located on the optical path of the reflected light of the first off-axis parabolic mirror, and is used to converge the light reflected by the first off-axis parabolic mirror to the sample to be measured. The focus of the reflected light of the second off-axis parabolic mirror is located at the sample to be measured.

[0014] In one or more embodiments of the present invention, the transmission optical path mechanism further includes a third off-axis parabolic mirror and a beam splitter;

[0015] The second off-axis parabolic mirror is located on the optical path of the reflected light of the sample to be measured, and is used to collimate and reflect the light reflected by the sample to be measured to the beam splitter;

[0016] The beam splitter is located on the optical path of the reflected light of the second off-axis parabolic mirror, and is used to reflect the light reflected by the second off-axis parabolic mirror to the third off-axis parabolic mirror;

[0017] The third off-axis parabolic mirror is located on the optical path of the reflected light of the beam splitter, and is used to converge the light reflected by the beam splitter to the reflected optical path acquisition detector.

[0018] In one or more embodiments of the present invention, the transmission optical path mechanism further includes a fourth off-axis parabolic mirror and a fifth off-axis parabolic mirror;

[0019] The fourth off-axis parabolic mirror is located on the optical path of the light beam projected through the sample to be measured, and is used to collimate and reflect the light beam emitted by the terahertz emission mechanism to the fifth off-axis parabolic mirror;

[0020] The fifth off-axis parabolic mirror is located on the optical path of the reflected light of the fourth off-axis parabolic mirror and is used to converge the light reflected by the fourth off-axis parabolic mirror into the transmission optical path acquisition detector. The focus of the reflected light of the fifth off-axis parabolic mirror is located at the transmission optical path acquisition detector.

[0021] In one or more embodiments of the present invention, the terahertz emission mechanism includes a terahertz source and a waveguide horn antenna. The waveguide horn antenna is located on the optical path of the terahertz beam emitted by the terahertz source and is used to make the terahertz beam have Gaussian characteristics.

[0022] In one or more embodiments of the present invention, the rotation drive mechanism is a rotary motor, and a position sensor is installed on the rotary motor.

[0023] In one or more embodiments of the present invention, a position sensor is installed on the linear drive mechanism.

[0024] In one or more embodiments of the present invention, the position sensor is a grating sensor or a photoelectric sensor.

[0025] In one or more embodiments of the present invention, different-sized slots for placing the sample to be measured are provided on the stage.

[0026] In one or more embodiments of the present invention, the detection device further includes a first bracket. The terahertz emission mechanism, the transmission optical path mechanism, the reflection optical path acquisition detector, and the transmission optical path acquisition detector are all installed on the first bracket, and the first bracket is connected to the sliding seat.

[0027] Compared with the prior art, the beneficial effects of the terahertz imaging system of the present invention are as follows:

[0028] (1) High-speed scanning: Install the turntable on the rotation drive mechanism and cooperate with the linear drive mechanism to achieve rapid two-dimensional scanning of the sample to be measured, greatly improving the imaging speed.

[0029] (2) Synchronous acquisition of transmission and reflection: Through the mutual cooperation of the transmission optical path mechanism, the reflection optical path acquisition detector, and the transmission optical path acquisition detector, synchronous acquisition of the transmission and reflection imaging of the sample to be measured is achieved.

[0030] (3) Simplified design and cost reduction: The imaging system designed by us adopts a simplified structure, reduces the manufacturing cost, and makes the terahertz imaging technology easier to be widely applied. Description of the Drawings

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0032] Figure 1 Stereogram of the terahertz imaging system in Embodiment 1 of the present invention;

[0033] Figure 2 Front view of the solid in Embodiment 1 of the present invention;

[0034] Figure 3 Imaging working principle diagram of the terahertz imaging system in an embodiment of the present invention;

[0035] Figure 4 Stereogram of the terahertz imaging system in Embodiment 2 of the present invention;

[0036] Figure 5 Test result diagram of the terahertz imaging system in Embodiment 2 of the present invention.

[0037] Main reference numeral description:

[0038] 1, carrying device; 11, rotation driving mechanism; 12, loading platform; 121, card slot; 13, second bracket; 2, detection device; 21, terahertz emission mechanism; 22, transmission optical path mechanism; 221, first off-axis parabolic mirror; 222, second off-axis parabolic mirror; 223, third off-axis parabolic mirror; 224, fourth off-axis parabolic mirror; 225, fifth off-axis parabolic mirror; 226, beam splitter; 211, terahertz source; 212, waveguide horn antenna; 23, reflection optical path acquisition detector; 24, transmission optical path acquisition detector; 25, first bracket; 3, linear driving device; 31, linear driving mechanism; 32, sliding seat. Detailed implementation manners

[0039] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] Embodiment 1

[0041] As Figure 1 and 2 shown, the terahertz imaging system in this embodiment includes a carrying device 1, a detection device 2, and a linear driving device 3; the carrying device 1 includes a rotation driving mechanism 11 and a stage 12 connected to the rotation end of the rotation driving mechanism 11, and the surface of the stage 12 is used to carry the sample to be measured; the detection device 2 includes a terahertz emission mechanism 21, a transmission optical path mechanism 22, a reflection optical path acquisition detector 23, and a transmission optical path acquisition detector 24. The transmission optical path mechanism 22 is used to transmit the terahertz wave emitted by the terahertz emission mechanism 21 to the sample to be measured on the surface of the stage 12, and reflect the terahertz wave reflected by the sample to be measured into the reflection optical path acquisition detector 23 and converge the terahertz wave transmitted through the sample to be measured into the transmission optical path acquisition detector 24; the linear driving device 3 includes a connected linear driving mechanism 31 and a sliding seat 32, and the linear driving mechanism 31 is used to drive the sliding seat 32 to perform a relative linear motion, and the detection device 2 is installed on the sliding seat 32.

[0042] It can be understood that the carrier plate in the terahertz imaging system of the present invention is installed on the rotation driving mechanism 11, and the detection device 2 is installed on the linear driving mechanism 31; during the detection process, the rotation driving mechanism 11 and the linear driving mechanism 31 cooperate in a spiral scanning mode or a concentric circle scanning mode to achieve rapid two-dimensional scanning of the sample to be measured, greatly improving the imaging speed. The terahertz emission mechanism 21 is used to emit terahertz light beams (which can also be called terahertz waves).

[0043] Among them, the spiral scanning mode is: the rotation driving mechanism 11 and the linear driving mechanism 31 run simultaneously, that is, the rotation driving mechanism 11 controls the rotation of the carrier plate, and the linear driving mechanism 31 controls the movement of the detection device 2, so that the light beam emitted by the detection device 2 onto the carrier plate presents a spiral-shaped movement trajectory on the surface of the carrier plate.

[0044] The concentric circle scanning mode is: the rotation driving mechanism 11 controls the rotation of the carrier plate. After the movement trajectory of the light beam emitted by the detection device 2 onto the carrier plate forms a circle on the surface of the carrier plate, the rotation driving mechanism 11 stops, and the linear driving mechanism 31 controls the movement of the detection device 2. After the light beam emitted by the detection device 2 onto the carrier plate moves out of the just movement trajectory along the radial direction of the carrier plate, the linear driving mechanism 31 stops; then the rotation driving mechanism 11 controls the rotation of the carrier plate again, so that the movement trajectory of the light beam emitted by the detection device 2 onto the carrier plate forms a new circle on the surface of the carrier plate; repeat the above steps repeatedly until the light beam converging on the stage 12 scans all of the sample to be measured or the light beam converging on the stage 12 scans all of the area on the stage 12 for placing the sample to be measured.

[0045] As Figure 1 and2 As shown, the detection device 2 further includes a first support 25. The terahertz emission mechanism 21, the transmission optical path mechanism 22, the reflection optical path acquisition detector 23, and the transmission optical path acquisition detector 24 are all installed on the first support 25. The first support 25 is connected to the sliding seat 32. The reflection optical path acquisition detector 23 and the transmission optical path acquisition detector 24 can be respectively located on the upper and lower sides of the stage 12. The carrying device 1 may include a second support 13. The rotation driving mechanism 11 is installed on the second support 13, and the stage 12 is installed on the rotating end of the rotation driving mechanism 11.

[0046] Preferably, as Figures 1 to 3 shown, the transmission optical path mechanism 22 includes a first off-axis parabolic mirror 221 and a second off-axis parabolic mirror 222. The first off-axis parabolic mirror 221 is located on the optical path of the beam emitted by the terahertz emission mechanism 21, and is used to collimate and reflect the beam emitted by the terahertz emission mechanism 21 onto the second off-axis parabolic mirror 222. The second off-axis parabolic mirror 222 is located on the optical path of the reflected light of the first off-axis parabolic mirror 221, and is used to converge the light reflected by the first off-axis parabolic mirror 221 to the position of the sample to be measured. The focus of the reflected light of the second off-axis parabolic mirror 222 is located at the position of the sample to be measured.

[0047] It can be understood that the cooperation of the first off-axis parabolic mirror 221 and the second off-axis parabolic mirror 222 serves to collimate, transmit, and converge the beam emitted by the terahertz emission mechanism 21 to the surface of the stage 12. In addition, the first off-axis parabolic mirror 221 and the second off-axis parabolic mirror 222 are reflective optical elements, and the reflective optical elements can reduce the attenuation of the power of the terahertz source 211 by the optical elements, thereby improving the signal-to-noise ratio and the image quality.

[0048] Further, the transmission optical path mechanism 22 further includes a third off-axis parabolic mirror 223 and a beam splitter 226. The second off-axis parabolic mirror 222 is located on the optical path of the reflected light of the sample to be measured, and is used to collimate and reflect the light reflected by the sample to be measured onto the beam splitter 226. The beam splitter 226 is located on the optical path of the reflected light of the second off-axis parabolic mirror 222, and is used to reflect the light reflected by the second off-axis parabolic mirror 222 onto the third off-axis parabolic mirror 223. The third off-axis parabolic mirror 223 is located on the optical path of the reflected light of the beam splitter 226, and is used to converge the light reflected by the beam splitter 226 into the reflection optical path acquisition detector 23.

[0049] The cooperation of the second off-axis parabolic mirror 222, the third off-axis parabolic mirror 223 and the beam splitter 226 serves to collimate, transmit and converge the light reflected by the sample to be measured into the reflection optical path acquisition detector 23. In addition, the third off-axis parabolic mirror 223 and the beam splitter 226 are reflective optical elements, and the reflective optical elements can reduce the attenuation of the power of the terahertz source 211 by the optical elements, thereby improving the signal-to-noise ratio and the image quality.

[0050] Furthermore, the transmission optical path mechanism 22 further includes a fourth off-axis parabolic mirror 224 and a fifth off-axis parabolic mirror 225; the fourth off-axis parabolic mirror 224 is located on the optical path of the beam projected through the sample to be measured, and is used to collimate and reflect the beam emitted by the terahertz emission mechanism 21 onto the fifth off-axis parabolic mirror 225; the fifth off-axis parabolic mirror 225 is located on the optical path of the reflected light of the fourth off-axis parabolic mirror 224, and is used to converge the light reflected by the fourth off-axis parabolic mirror 224 into the transmission optical path acquisition detector 24, and the focus of the reflected light of the fifth off-axis parabolic mirror 225 is located at the transmission optical path acquisition detector 24.

[0051] The cooperation of the fourth off-axis parabolic mirror 224 and the fifth off-axis parabolic mirror 225 serves to collimate, transmit and converge the light transmitted through the sample to be measured into the transmission optical path acquisition detector 24. In addition, the fourth off-axis parabolic mirror 224 and the fifth off-axis parabolic mirror 225 are reflective optical elements, and the reflective optical elements can reduce the attenuation of the power of the terahertz source 211 by the optical elements, thereby improving the signal-to-noise ratio and the image quality.

[0052] In this embodiment, the terahertz emission mechanism 21 includes a terahertz source 211 and a waveguide horn antenna 212. The waveguide horn antenna 212 is located on the optical path of the terahertz beam emitted by the terahertz source 211, and is used to make the terahertz beam have Gaussian characteristics, that is, a terahertz beam with Gaussian characteristics. The waveguide horn antenna is an aperture antenna, and mainly realizes the impedance matching between the waveguide port and the free space through the reflection of the inner wall topography of the metal. By designing the aperture and axial length of the waveguide horn antenna, the gain and directivity required for a given application can be obtained. The waveguide horn antenna can be a pyramid (rectangular) horn, a conical horn, a sector horn, a horn lens, a corrugated feed horn, a probe or an omnidirectional horn. Its Gaussian characteristics are mainly affected by the phase of the propagation optical path.

[0053] Preferably, the rotation driving mechanism 11 is a rotary motor, and a position sensor is installed on the rotary motor. The position sensor is used to detect and calculate the angular position of the scanning optical path in the carrier plate.

[0054] Furthermore, a position sensor is installed on the linear drive mechanism 31. The angular position of the scanning optical path in the carrier plate is detected and calculated. The linear drive mechanism 31 can be a linear stepper motor, an electric cylinder, etc.

[0055] When position sensors are installed on both the rotational drive mechanism 11 and the linear drive mechanism 31, the angular position of the scanning optical path in the carrier plate can be calculated more accurately and quickly.

[0056] Specifically, the position sensor is a grating sensor or a photoelectric sensor.

[0057] The carrier stage 12 is provided with slots 121 of different sizes for placing the sample to be measured, which serves to fix and limit the sample to be measured.

[0058] Embodiment 2

[0059] As Figure 4 shown, the terahertz imaging system in this embodiment includes a carrier device 1, a detection device 2, and a linear drive device 3; the carrier device 1 includes a rotational drive mechanism 11 and a carrier stage 12 connected to the rotational end of the rotational drive mechanism 11, and the surface of the carrier stage 12 is used to carry the sample to be measured; the detection device 2 includes a terahertz emission mechanism 21, a transmission optical path mechanism 22, a reflected optical path acquisition detector 23, and a transmitted optical path acquisition detector 24. The transmission optical path mechanism 22 is used to transmit the terahertz wave emitted by the terahertz emission mechanism 21 to the sample to be measured on the surface of the carrier stage 12, and reflect the terahertz wave reflected by the sample to be measured into the reflected optical path acquisition detector 23 and converge the terahertz wave transmitted through the sample to be measured into the transmitted optical path acquisition detector 24; the linear drive device 3 includes a connected linear drive mechanism 31 and a sliding seat 32, and the linear drive mechanism 31 is used to drive the sliding seat 32 to perform a relative linear motion, and the carrier device 1 is installed on the sliding seat 32.

[0060] It can be understood that the carrier plate in the terahertz imaging system of the present invention is installed on the rotational drive mechanism 11, and the carrier device 1 is installed on the linear drive mechanism 31; during the detection process, the rotational drive mechanism 11 and the linear drive mechanism 31 cooperate in a spiral scan mode or a concentric circle scan mode to achieve rapid two-dimensional scanning of the sample to be measured, greatly improving the imaging speed. That is, the rotational drive mechanism 11 is installed on the sliding seat 32. The terahertz emission mechanism 21 is used to emit terahertz light beams (which can also be called terahertz waves).

[0061] Among them, the spiral scan mode is as follows: the rotation driving mechanism 11 and the linear driving mechanism 31 operate simultaneously, that is, the rotation driving mechanism 11 controls the rotation of the sample stage, and the linear driving mechanism 31 controls the movement of the carrying device 1, so that the light beam emitted by the detection device 2 onto the sample stage presents a spiral-shaped movement trajectory on the surface of the sample stage.

[0062] The concentric circle scan mode is as follows: the rotation driving mechanism 11 controls the rotation of the sample stage. After the movement trajectory of the light beam emitted by the detection device 2 onto the sample stage forms a circle, the rotation driving mechanism 11 stops. Then the linear driving mechanism 31 controls the movement of the carrying device 1, so that the light beam emitted by the detection device 2 onto the sample stage moves radially out of the just-mentioned movement trajectory, and then the linear driving mechanism 31 stops; then the rotation driving mechanism 11 controls the rotation of the sample stage again, so that the movement trajectory of the light beam emitted by the detection device 2 onto the sample stage forms a new circle; repeat the above steps repeatedly until the light beam converging to the sample stage 12 scans the entire measured sample or the light beam converging to the sample stage 12 scans the entire area on the sample stage 12 for placing the measured sample.

[0063] As Figure 4 shown, the detection device 2 further includes a first bracket 25. The terahertz emission mechanism 21, the transmission optical path mechanism 22, the reflection optical path acquisition detector 23, and the transmission optical path acquisition detector 24 are all installed on a fixed bracket; the reflection optical path acquisition detector 23 and the transmission optical path acquisition detector 24 can be respectively located on the upper and lower sides of the sample stage 12. The rotation driving mechanism 11 of the carrying device 1 can be installed on the first bracket 25, and the sample stage 12 is installed on the rotation end of the rotation driving mechanism 11.

[0064] Preferably, as Figure 3 and 4 shown, the transmission optical path mechanism 22 includes a first off-axis parabolic mirror 221 and a second off-axis parabolic mirror 222; the first off-axis parabolic mirror 221 is located on the optical path of the light beam emitted by the terahertz emission mechanism 21 and is used to collimate and reflect the light beam emitted by the terahertz emission mechanism 21 onto the second off-axis parabolic mirror 222; the second off-axis parabolic mirror 222 is located on the optical path of the reflected light of the first off-axis parabolic mirror 221 and is used to converge the light reflected by the first off-axis parabolic mirror 221 to the measured sample, and the focus of the reflected light of the second off-axis parabolic mirror 222 is located at the measured sample.

[0065] It can be understood that the cooperation of the first off-axis parabolic mirror 221 and the second off-axis parabolic mirror 222 serves to collimate, transmit, and converge the light beam emitted by the terahertz emission mechanism 21 onto the surface of the sample stage 12. Additionally, the first off-axis parabolic mirror 221 and the second off-axis parabolic mirror 222 are reflective optical elements, and reflective optical elements can reduce the attenuation of the power of the terahertz source 211 by the optical elements, thereby improving the signal-to-noise ratio and the image quality.

[0066] Furthermore, the transmission optical path mechanism 22 further includes a third off-axis parabolic mirror 223 and a beam splitter 226; the second off-axis parabolic mirror 222 is located on the optical path of the reflected light of the sample to be measured, and is used to collimate and reflect the light reflected by the sample to be measured onto the beam splitter 226; the beam splitter 226 is located on the optical path of the reflected light of the second off-axis parabolic mirror 222, and is used to reflect the light reflected by the second off-axis parabolic mirror 222 onto the third off-axis parabolic mirror 223; the third off-axis parabolic mirror 223 is located on the optical path of the reflected light of the beam splitter 226, and is used to converge the light reflected by the beam splitter 226 into the reflection optical path acquisition detector 23.

[0067] Through the cooperation of the second off-axis parabolic mirror 222, the third off-axis parabolic mirror 223, and the beam splitter 226, the light reflected by the sample to be measured is collimated, transmitted, and converged into the reflection optical path acquisition detector 23. Additionally, the third off-axis parabolic mirror 223 and the beam splitter 226 are reflective optical elements, and reflective optical elements can reduce the attenuation of the power of the terahertz source 211 by the optical elements, thereby improving the signal-to-noise ratio and the image quality.

[0068] Furthermore, the transmission optical path mechanism 22 further includes a fourth off-axis parabolic mirror 224 and a fifth off-axis parabolic mirror 225; the fourth off-axis parabolic mirror 224 is located on the optical path of the light beam passing through the sample to be measured, and is used to collimate and reflect the light beam emitted by the terahertz emission mechanism 21 onto the fifth off-axis parabolic mirror 225; the fifth off-axis parabolic mirror 225 is located on the optical path of the reflected light of the fourth off-axis parabolic mirror 224, and is used to converge the light reflected by the fourth off-axis parabolic mirror 224 into the transmission optical path acquisition detector 24, and the focus of the reflected light of the fifth off-axis parabolic mirror 225 is located at the transmission optical path acquisition detector 24.

[0069] Through the cooperation of the fourth off-axis parabolic mirror 224 and the fifth off-axis parabolic mirror 225, the light passing through the sample to be measured is collimated, transmitted, and converged into the transmission optical path acquisition detector 24. Additionally, the fourth off-axis parabolic mirror 224 and the fifth off-axis parabolic mirror 225 are reflective optical elements, and reflective optical elements can reduce the attenuation of the power of the terahertz source 211 by the optical elements, thereby improving the signal-to-noise ratio and the image quality.

[0070] In this embodiment, the terahertz emission mechanism 21 includes a terahertz source 211 and a waveguide horn antenna 212. The waveguide horn antenna 212 is located on the optical path of the terahertz beam emitted by the terahertz source 211 and is used to endow the terahertz beam with Gaussian characteristics, that is, a terahertz beam with Gaussian characteristics. The waveguide horn antenna is an aperture antenna, which mainly realizes the impedance matching between the waveguide port and free space through the reflection of the inner wall topography of the metal. By designing the aperture and axial length of the waveguide horn antenna, the gain and directivity required for a given application can be obtained. The waveguide horn antenna can be a pyramidal (rectangular) horn, a conical horn, a sector horn, a horn lens, a corrugated feed horn, a probe or an omnidirectional horn. Its Gaussian characteristics are mainly affected by the phase of the propagation optical path.

[0071] Preferably, the rotation driving mechanism 11 is a rotary motor, and a position sensor is installed on the rotary motor. The position sensor is used to detect and calculate the angular position of the scanning optical path in the carrier plate.

[0072] Furthermore, a position sensor is installed on the linear driving mechanism 31. The angular position of the scanning optical path in the carrier plate is detected and calculated.

[0073] When both the rotation driving mechanism 11 and the linear driving mechanism 31 are equipped with position sensors, the angular position of the scanning optical path in the carrier plate can be calculated more accurately and quickly.

[0074] Specifically, the position sensor is a grating sensor or a photoelectric sensor.

[0075] Different-sized slots 121 for placing the sample to be measured are provided on the stage 12, which play a role in fixing and restricting the sample to be measured.

[0076] Using the terahertz imaging system of this embodiment for physical testing, Figure 5 is the test result diagram of the terahertz imaging system. Through Figure 5 it can be seen that this terahertz imaging system has good imaging comprehensiveness and accuracy.

[0077] The terahertz rapid imaging scanning method of the present utility model can simultaneously obtain the transmission and reflection imaging information of the sample to be measured, which not only expands the acquisition method of imaging information, but also improves the imaging comprehensiveness and accuracy.

[0078] In summary, the beneficial effects of the terahertz imaging system of the present utility model are as follows:

[0079] (1) High-speed scanning: By introducing the cooperation of the rotation driving mechanism and the linear driving mechanism, rapid two-dimensional scanning of the sample to be measured is realized, and the imaging speed is greatly improved.

[0080] (2) Transmissive and reflective synchronous scanning: The present utility model adopts the method of transmissive and reflective synchronous scanning, which can simultaneously obtain the transmissive and reflective terahertz signals of the target. This not only expands the acquisition method of imaging information, but also improves the comprehensiveness and accuracy of imaging.

[0081] (3) Optimized optical elements: Reflective optical elements are adopted to reduce the attenuation of the terahertz source power by the optical elements, thereby improving the signal-to-noise ratio and the image quality.

[0082] (4) High resolution: By optimizing the designs of the terahertz emitter, receiver and detector, the imaging resolution is improved, enabling the system to better capture the microscopic details of the target.

[0083] (5) Simplified system structure: The system design of the present utility model is relatively simplified, reducing the complexity of the system. This helps to reduce the manufacturing cost and improve the stability and reliability of the system.

[0084] (6) Wide applicability: Due to the advantages of the present utility model in terms of imaging speed, transmissive and reflective synchronous scanning and resolution, it is applicable to multiple fields such as materials and medicine, expanding the application scope of terahertz imaging technology.

[0085] For those skilled in the art, it is obvious that the present utility model is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present utility model is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present utility model. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0086] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A terahertz imaging system, characterized in that: include: The carrying device comprises a rotation driving mechanism and a stage connected to the rotating end of the rotation driving mechanism, wherein the surface of the stage is used to carry the sample to be tested; The detection device comprises a terahertz emission mechanism, a transmission optical path mechanism, a reflection optical path collection detector and a transmission optical path collection detector, wherein the transmission optical path mechanism is used to transmit the terahertz wave emitted by the terahertz emission mechanism to the sample under test on the surface of the stage, and reflect the terahertz wave reflected by the sample under test into the reflection optical path collection detector, and converge the terahertz wave transmitted through the sample under test into the transmission optical path collection detector; The linear drive device comprises a linear drive mechanism and a sliding seat connected to each other, wherein the linear drive mechanism is used to drive the sliding seat to perform relative linear motion, and the bearing device or the detection device is installed on the sliding seat.

2. The terahertz imaging system according to claim 1, characterized in that: The transmission optical path mechanism comprises a first off-axis parabolic mirror and a second off-axis parabolic mirror; The first off-axis parabolic mirror is located on the optical path of the light beam emitted by the terahertz emission mechanism, and is used to collimate the light beam emitted by the terahertz emission mechanism and reflect it onto the second off-axis parabolic mirror; The second off-axis parabolic mirror is located on the optical path of the reflected light of the first off-axis parabolic mirror, and is used to converge the light reflected by the first off-axis parabolic mirror to the sample under test. The focus of the reflected light of the second off-axis parabolic mirror is located at the sample under test.

3. The terahertz imaging system according to claim 2, characterized in that: The transmission optical path mechanism also includes a third off-axis parabolic mirror and a beam splitter; The second off-axis parabolic mirror is located on the optical path of the reflected light of the measured sample, and is used to collimate the light reflected by the measured sample and reflect it onto the beam splitter; The beam splitter is located on the optical path of the reflected light of the second off-axis parabolic mirror, and is used to reflect the light reflected by the second off-axis parabolic mirror onto the third off-axis parabolic mirror; The third off-axis parabolic mirror is located on the optical path of the reflected light of the beam splitter, and is used to converge the light reflected by the beam splitter into the reflected light path collection detector.

4. The terahertz imaging system according to claim 2, characterized in that: The transmission optical path mechanism also includes a fourth off-axis parabolic mirror and a fifth off-axis parabolic mirror; The fourth off-axis parabolic mirror is located on the optical path of the light beam projected through the sample to be tested, and is used to collimate the light beam emitted by the terahertz emission mechanism and reflect it onto the fifth off-axis parabolic mirror; The fifth off-axis parabolic mirror is located on the optical path of the reflected light of the fourth off-axis parabolic mirror, and is used to converge the light reflected by the fourth off-axis parabolic mirror into the transmitted light path collection detector. The focus of the reflected light of the fifth off-axis parabolic mirror is located at the transmitted light path collection detector.

5. The terahertz imaging system according to claim 1, characterized in that: The terahertz emission mechanism comprises a terahertz source and a waveguide horn antenna. The waveguide horn antenna is located on the optical path of the terahertz light beam emitted by the terahertz source and is used to make the terahertz light beam have Gaussian characteristics.

6. The terahertz imaging system according to claim 1, characterized in that: The rotation driving mechanism is a rotary motor, and a position sensor is installed on the rotary motor.

7. The terahertz imaging system according to claim 1, characterized in that: A position sensor is installed on the linear drive mechanism.

8. The terahertz imaging system according to claim 6 or 7, characterized in that: The position sensor is a grating sensor or a photoelectric sensor.

9. The terahertz imaging system according to claim 1, characterized in that: The stage is provided with slots of different sizes for placing the samples to be tested.

10. The terahertz imaging system according to claim 1, characterized in that: The detection device also includes a first bracket, and the terahertz emission mechanism, the transmission light path mechanism, the reflection light path collection detector and the transmission light path collection detector are all installed on the first bracket, and the first bracket is connected to the sliding seat.

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