Electro-optical sampling device based on terahertz topological insulator

Abstract

The embodiment of the invention discloses an electro-optical sampling device based on a terahertz topological insulator. In a specific implementation mode, the device comprises a terahertz electromagnetic wave link structure, an electro-optical sampling chip, an optical link structure and a balanced photoelectric detector, and the terahertz electromagnetic wave link structure is used for realizing transmission of input terahertz electromagnetic waves and output terahertz electromagnetic waves; the optical link structure is used for realizing transmission of input sampling light and output sampling light; the electro-optical sampling chip is used for transmitting input terahertz electromagnetic waves in the terahertz topological waveguide structure on the surface of the electro-optical sampling chip to obtain output terahertz electromagnetic waves; the electro-optical sampling chip is also used for enabling the input sampling light and the input terahertz electromagnetic wave to generate an electro-optical effect in the electro-optical sampling chip to obtain output sampling light; and the balanced photoelectric detector is used for converting the output sampling light into a current signal. The invention has the advantages of low transmission loss, strong anti-interference capability, small volume, integration and the like.

Description

Technical Field

[0001] The present invention relates to the field of precision measurement technology, and more specifically, to an electro-optical sampling device based on a terahertz topological insulator. Background Art

[0002] At present, thanks to the advantages of wide bandwidth, good penetration, high safety and non-destructive testing, terahertz electromagnetic waves have been widely used in civil and military fields such as material detection, imaging safety, non-destructive testing, ultra-wideband wireless communication, material electromagnetic parameter measurement, metrology calibration, space detection, radar and weapons and equipment, effectively promoting the rapid development of terahertz electromagnetic waveform parameter measurement technology.

[0003] As we all know, the existing terahertz transmission interconnection structures are basically based on metal materials, and metal materials have strong absorption of terahertz electromagnetic waves. The higher the frequency, the greater the absorption loss, which leads to extremely large losses in the terahertz electro-optical sampling system. In addition, as the operating frequency of terahertz electromagnetic waves increases, the metal cavity processing defects of the terahertz transmission interconnection structure become more sensitive, and the precision requirements for the process are also higher. Not only that, due to the limitations of the existing technical system, in application scenarios where electromagnetic wave direction conversion is required, in order to avoid causing large scattering losses, the spatial volume of the entire system is usually large and has strong limitations.

[0004] Topological insulators are a new type of quantum material that is conductive on the surface but insulators inside. Terahertz topological insulators are a generalization of electronic topological insulators and can be seen as a simulation of electronic topological insulators. The most direct property of these materials is that they are terahertz "insulators" - they are not transparent to terahertz electromagnetic waves, but their boundaries can support the transmission of a type of terahertz electromagnetic wave.

[0005] The present invention proposes an electro-optical sampling device based on a terahertz topological insulator for measuring terahertz waveform parameters. An on-chip terahertz topological waveguide structure is used to replace a traditional terahertz transmission interconnection metal cavity structure, which can effectively reduce the transmission loss and processing difficulty of the terahertz transmission interconnection structure, and provide a terahertz wave electro-optical sampling module with a wide bandwidth, small size, integrability, low dispersion, and strong anti-interference ability, so as to realize high-fidelity real-time online measurement of terahertz pulse signals. Summary of the invention

[0006] The object of the present invention is to provide an optical topological insulator electro-optical sampling device for measuring terahertz electromagnetic waveform parameters, so as to solve at least one of the problems existing in the prior art.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides

[0009] An electro-optical sampling device based on a terahertz topological insulator comprises: a terahertz electromagnetic wave link structure, an electro-optical sampling chip, an optical link structure and a balanced photodetector.

[0010] The terahertz electromagnetic wave link structure is used to realize the transmission of input terahertz electromagnetic waves and output terahertz electromagnetic waves;

[0011] The optical link structure is used to realize the transmission of input sampling light and output sampling light;

[0012] The electro-optic sampling chip is used to transmit the input terahertz electromagnetic wave in the terahertz topological waveguide structure on the surface of the electro-optic sampling chip to obtain the output terahertz electromagnetic wave; and is also used to generate an electro-optic effect between the input sampling light and the input terahertz electromagnetic wave in the electro-optic sampling chip to obtain the output sampling light;

[0013] The balanced photodetector is used to convert the output sampling light into a current signal.

[0014] Optionally, the propagation direction of the input sampling light is orthogonal to the transmission direction of the input terahertz electromagnetic wave;

[0015] The propagation direction of the output sampling light is orthogonal to the transmission direction of the output terahertz electromagnetic wave.

[0016] Optionally, the terahertz electromagnetic wave link structure includes a terahertz electromagnetic wave input port and a terahertz electromagnetic wave output port.

[0017] The terahertz electromagnetic wave input port is used to transmit the input terahertz electromagnetic wave generated by the terahertz electromagnetic wave generator to the electro-optical sampling chip;

[0018] The terahertz electromagnetic wave output port is used to output the terahertz electromagnetic wave.

[0019] Optionally, the terahertz electromagnetic wave input port and the terahertz electromagnetic wave output port are interconnected with the electro-optical sampling chip via a flexible dielectric waveguide.

[0020] Optionally, the terahertz electromagnetic wave link structure further includes a matching load.

[0021] The matching load is connected to the terahertz electromagnetic wave output port and is used for absorbing the output terahertz electromagnetic wave to reduce reflection of the output terahertz electromagnetic wave.

[0022] Optionally, the optical link structure includes a fiber-coupled structure or a spatial light transmission structure;

[0023] The fiber-coupled structure is used to couple the input sampling light fiber to the electro-optical sampling chip, and is also used to separate the output sampling light into two beams with orthogonal polarization directions, and transmit them to the balanced photodetector;

[0024] The spatial light transmission structure is used to adjust the direction and shape the input sampling light transmitted in the free space, and is also used to separate the output sampling light into two beams of orthogonal polarized light and transmit them to the balanced photodetector.

[0025] Optionally, the spatial light transmission optical link structure includes

[0026] Polarizer, 1 / 2 wave plate, beam focusing and collimating system, 1 / 4 wave plate, Wollaston prism and reflector group,

[0027] The polarizer, 1 / 2 wave plate and 1 / 4 wave plate are used to adjust the polarization state and polarization direction of the input sampling light so that it forms a first angle with the transmission direction of the terahertz electromagnetic wave in the electro-optical sampling chip;

[0028] The beam focusing and collimating system is used to shape the input sampling light incident on the electro-optical sampling chip into parallel light;

[0029] The Wollaston prism is used to separate the output sampling light transmitted through the electro-optical sampling chip into two beams of orthogonal polarized light.

[0030] The reflector group is used to direct the separated orthogonal polarized light into the balanced photodetector.

[0031] Optionally, the fiber-coupled structure includes

[0032] Fiber-coupled chip cavity, input single-mode polarization-maintaining lens fiber, output single-mode polarization-maintaining lens fiber and fiber polarization beam splitter;

[0033] The electro-optical sampling chip is placed in the fiber-coupled chip cavity;

[0034] The fiber-coupled chip cavity is provided with fiber-coupled packaging holes on both sides of the cavity perpendicular to the surface of the electro-optical sampling chip, which are respectively an input fiber-coupled packaging hole and an output fiber-coupled packaging hole;

[0035] The input single-mode polarization-maintaining lens optical fiber is used to inject the input sampling light into the electro-optical sampling chip through the input optical fiber coupling packaging hole.

[0036] The output single-mode polarization-maintaining lens optical fiber is used to receive the output sampling light transmitted through the electro-optical sampling chip through the output optical fiber coupling packaging hole;

[0037] The optical fiber polarization beam splitter is connected to the output single-mode polarization-maintaining lens optical fiber and is used to separate the output sampling light passing through the electro-optical sampling chip into two beams of light with orthogonal polarization directions.

[0038] Optionally, the terahertz topological waveguide structure on the surface of the electro-optical sampling chip is obtained by laser drilling or dry etching semiconductor process.

[0039] Optionally, the electro-optical sampling chip is an electro-optical sampling chip with a double-sided polished substrate material.

[0040] The beneficial effects of the present invention are as follows:

[0041] Compared with the traditional electro-optical sampling system based on metal materials, the electro-optical sampling device based on terahertz topological insulator provided by the present invention has the advantages of small transmission loss, strong anti-interference ability, small size and integration, and can be applied to various complex testing environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0043] Figure 1 A schematic diagram showing the spatial light transmission type terahertz topological insulator electro-optical sampling module of the present invention is shown.

[0044] Figure 2 A schematic diagram showing a fiber-coupled terahertz topological insulator electro-optical sampling module of the present invention is shown.

[0045] Figure 3 A schematic diagram of a spatial light transmission optical link of the present invention is shown.

[0046] Figure 4 A schematic diagram of a fiber-coupled optical link of the present invention is shown.

[0047] Figure 5 A schematic diagram of a synchronous sampling measurement system in a terahertz topological insulator electro-optical sampling device for measuring terahertz electromagnetic waveform parameters according to the present invention is shown.

[0048] Figure 6 A schematic diagram of an asynchronous sampling measurement system in a terahertz topological insulator electro-optical sampling device for measuring terahertz electromagnetic waveform parameters according to the present invention is shown.

[0049] Figure numerals: 1. Input terahertz electromagnetic wave, 2. Terahertz electromagnetic wave input port, 3. First flexible dielectric waveguide, 4. Electro-optical sampling chip, 5. Input sampling light, 6. Output sampling light, 7. Second flexible dielectric waveguide, 8. Terahertz electromagnetic wave output port, 9. Matching load, 10. 1 / 2 wave plate, 11. Beam focusing and collimation system; 12. 1 / 4 wave plate, 13. Wollaston prism, 14. Reflector group, 15. Balanced photodetector, 16. Input single-mode polarization-maintaining lens fiber, 17. Output single-mode polarization-maintaining lens fiber, 18. Fiber polarization beam splitter; 19. Fiber-coupled chip cavity, 20. Femtosecond laser A, 21. Fiber delay line, 22. Data acquisition and analysis module, 23. Ultrafast pulse generator, 24. Femtosecond laser B. DETAILED DESCRIPTION

[0050] In order to more clearly illustrate the present invention, the following embodiments and accompanying drawings are provided. Figure 1-6 The present invention is further described. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0051] Embodiment 1,

[0052] like Figure 1 As shown, the present invention discloses a spatial light transmission type terahertz topological insulator electro-optical sampling device for measuring terahertz electromagnetic waveform parameters, including a terahertz electromagnetic wave link structure, an electro-optical sampling chip 4 and an optical link structure.

[0053] The terahertz electromagnetic wave link structure is used to achieve low-loss, wide-bandwidth terahertz electromagnetic wave transmission;

[0054] The optical link structure is used to achieve ultrafast femtosecond sampling light transmission with high coupling efficiency;

[0055] The electro-optic sampling chip 4 is used to transmit the input terahertz electromagnetic wave in the terahertz topological waveguide structure on the surface of the electro-optic sampling chip 4 to obtain the output terahertz electromagnetic wave; it is also used to generate an electro-optic effect between the input sampling light and the input terahertz electromagnetic wave in the electro-optic sampling chip 4 to obtain the output sampling light, so as to realize the sampling of the terahertz electromagnetic wave.

[0056] The propagation direction of the input sampling light is orthogonal to the transmission direction of the input terahertz electromagnetic wave.

[0057] The terahertz electromagnetic wave link structure includes

[0058] A terahertz electromagnetic wave input port 2 and a terahertz electromagnetic wave output port 8;

[0059] The terahertz electromagnetic wave input port 2 is used to input the input terahertz electromagnetic wave 1 generated by the terahertz electromagnetic wave generator into the electro-optical sampling chip 4;

[0060] The terahertz electromagnetic wave output port 8 is used to output the terahertz electromagnetic wave.

[0061] The terahertz electromagnetic wave input port 2 and the terahertz electromagnetic wave output port 8 are interconnected with the terahertz topological waveguide of the electro-optical sampling chip through a flexible dielectric waveguide.

[0062] The terahertz electromagnetic wave link structure also includes a matching load 9 .

[0063] The matching load 9 is connected to the terahertz electromagnetic wave output port 8 and is used to absorb the terahertz electromagnetic wave to reduce the reflection of the terahertz electromagnetic wave.

[0064] Specifically, Figure 1 As shown, the input terahertz electromagnetic wave 11 generated by the terahertz electromagnetic wave generator radiates outward through the terahertz electromagnetic wave input port 2, is fed into the terahertz topological waveguide structure on the surface of the electro-optical sampling chip 4 through the first flexible dielectric waveguide 3, and after being transmitted on the surface of the electro-optical sampling chip 4, is connected to the matching load 9 through the second flexible dielectric waveguide 7 and the terahertz electromagnetic wave output port 8; the input sampling light 5 is input into the electro-optical sampling chip 4 to obtain the output sampling light 6; the transmission direction of the terahertz electromagnetic wave is perpendicular to the transmission direction of the sampling light. The on-chip terahertz topological waveguide structure on the surface of the electro-optical sampling chip 4 can be prepared by laser drilling or dry etching semiconductor process.

[0065] like Figure 3 As shown, the optical link structure is a spatial light transmission optical link structure, and the central wavelength of the sampling light transmitted by the spatial light transmission optical link structure is 1550nm, and the pulse width is in the order of femtoseconds;

[0066] The spatial light transmission structure is used to adjust the direction and shape the input sampling light 5 transmitted in the free space, and is also used to convert the output sampling light 6 into a first current signal.

[0067] The spatial light transmission type optical link structure includes

[0068] The polarizer, the half wave plate 10 and the quarter wave plate 12 are used to adjust the polarization state and polarization direction of the input sampling light 5 so that it forms a first angle with the transmission direction of the terahertz electromagnetic wave in the electro-optical sampling chip; preferably, it forms a 45° angle with the transmission direction of the terahertz wave in the electro-optical sampling chip;

[0069] The beam focusing and collimating system 11 is used to shape the input sampling light 5 incident on the electro-optical sampling chip into parallel light of a suitable spot size;

[0070] The Wollaston prism 13 is used to separate the output sampling light 6 transmitted through the electro-optical sampling chip into two beams of orthogonal polarized light;

[0071] A reflector group 14 is used to direct the separated orthogonal polarized light to a balanced photodetector;

[0072] The balanced photodetector 15 is used to convert the received orthogonal polarized light into a first current signal.

[0073] The detailed optical link is as follows Figure 3 As shown, the 1 / 2 wave plate 10 and the 1 / 4 wave plate 12 are used to adjust the polarization state and polarization direction of the transmitted light, so that it forms a 45° angle with the transmission direction of the terahertz electromagnetic wave in the electro-optical sampling chip 4, the beam focusing and collimating system 11 shapes the input sampling light 5 incident on the electro-optical sampling chip 4 into parallel light of a suitable spot size, the Wollaston prism 13 is used to separate the output sampling light 6 passing through the electro-optical sampling chip 4 into two orthogonal polarized lights, and the reflector group 14 incidents the separated orthogonal polarized lights onto the balanced photodetector 15. In the terahertz electromagnetic wave link structure of the device, the transmission direction of the terahertz electromagnetic wave is perpendicular to the transmission direction of the sampling light.

[0074] In a specific embodiment, the electro-optic sampling chip is an electro-optic sampling chip with a double-sided polished substrate material; the thickness is about micro-nanometer level, and the absorption loss of terahertz waves is low and the transmittance of light is high.

[0075] Embodiment 2,

[0076] like Figure 2 As shown, the present invention also discloses a fiber-coupled terahertz topological insulator electro-optical sampling device for measuring terahertz electromagnetic waveform parameters, comprising: a terahertz electromagnetic wave link structure, an electro-optical sampling chip and an optical link structure.

[0077] The terahertz electromagnetic wave link structure is used to realize the transmission of the input terahertz electromagnetic wave 1 and the output terahertz electromagnetic wave;

[0078] The optical link structure is used to realize the transmission of input sampling light and output sampling light;

[0079] The electro-optic sampling chip 4 is used to transmit the input terahertz electromagnetic wave in the terahertz topological waveguide structure on the surface of the electro-optic sampling chip 4 to obtain the output terahertz electromagnetic wave; it is also used to generate an electro-optic effect between the input sampling light and the input terahertz electromagnetic wave in the electro-optic sampling chip 4 to obtain the output sampling light, so as to realize the sampling of the terahertz electromagnetic wave.

[0080] The propagation direction of the input sampling light is orthogonal to the transmission direction of the input terahertz electromagnetic wave.

[0081] The terahertz electromagnetic wave link structure includes

[0082] A terahertz electromagnetic wave input port 2 and a terahertz electromagnetic wave output port 8.

[0083] The terahertz electromagnetic wave input port 2 is used to input the input terahertz electromagnetic wave 1 generated by the terahertz electromagnetic wave generator into the electro-optical sampling chip;

[0084] The terahertz electromagnetic wave output port 8 is used to output the terahertz electromagnetic wave.

[0085] The terahertz electromagnetic wave input port 2 and the terahertz electromagnetic wave output port 8 are interconnected with the terahertz topological waveguide of the electro-optical sampling chip through a flexible dielectric waveguide.

[0086] The terahertz electromagnetic wave link structure further includes a matching load 9 . The matching load 9 is connected to the terahertz electromagnetic wave output port 8 and is used to reduce reflection of the terahertz electromagnetic wave.

[0087] Specifically, Figure 2 As shown, the input terahertz electromagnetic wave 1 generated by the terahertz electromagnetic wave generator radiates outward through the terahertz electromagnetic wave input port 2, is fed into the terahertz topological waveguide structure on the surface of the electro-optical sampling chip 4 through the first flexible dielectric waveguide 3, and after being transmitted on the surface of the electro-optical sampling chip 4, is connected to the matching load 9 through the second flexible dielectric waveguide 7 and the terahertz electromagnetic wave output port 8. The input sampling light 5 is input into the electro-optical sampling chip 4 to obtain the output sampling light 6. The transmission direction of the terahertz electromagnetic wave is perpendicular to the transmission direction of the sampling light. The on-chip terahertz topological waveguide structure on the surface of the electro-optical sampling chip 4 can be prepared by laser drilling or dry etching semiconductor process.

[0088] like Figure 2 As shown, the electro-optical sampling chip 4 is placed in the fiber-coupled chip cavity 19;

[0089] The fiber-coupled chip cavity 19 is provided with fiber-coupled packaging holes on both sides of the cavity perpendicular to the surface of the electro-optical sampling chip 4, which are respectively an input fiber-coupled packaging hole and an output fiber-coupled packaging hole.

[0090] like Figure 4 As shown, the optical link structure is a fiber-coupled optical link structure; the fiber-coupled optical link structure is used to input the sampling light 5 into the electro-optical sampling chip, and is also used to convert the output sampling light 6 into a second current signal;

[0091] The optical fiber coupling structure includes

[0092] An input single-mode polarization-maintaining lens fiber 16, an output single-mode polarization-maintaining lens fiber 17, a fiber polarization beam splitter 18 and a balanced photodetector 15; wherein the input single-mode polarization-maintaining lens fiber 16 and the output single-mode polarization-maintaining lens fiber 17 are both long focal lengths, with a focal length of 180m, a light spot of about 30m at the focus, and the slow axis direction of the optical fiber forms an angle of 45° with the transmission direction of the terahertz wave in the electro-optical sampling chip.

[0093] The input single-mode polarization-maintaining lens optical fiber 16 is used to inject the input sampling light 5 into the electro-optical sampling chip through the input optical fiber coupling package hole.

[0094] An output single-mode polarization-maintaining lens optical fiber 17 is used to receive the output sampling light 6 transmitted through the electro-optical sampling chip through the output optical fiber coupling packaging hole;

[0095] The optical fiber polarization beam splitter 18 is connected to the output single-mode polarization-maintaining lens optical fiber 17 and is used to separate the output sampling light 6 transmitted through the electro-optic sampling chip 4 into two beams of light with orthogonal polarization directions.

[0096] The balanced photodetector 15 is used to receive two light beams with orthogonal polarization directions and convert them into a second current signal.

[0097] Specifically, the slow axis direction of the input single-mode polarization-maintaining lens fiber 16 forms an angle of 45° with the transmission direction of the terahertz electromagnetic wave in the electro-optical sampling chip 4, the focal length of the optical fiber is 180m, the light spot at the focus is about 30m, and the parallel incidence of the input sampling light 5 can be achieved within the range of ±10m at the focus. The optical fiber polarization beam splitter 18 is connected to the output single-mode polarization-maintaining lens fiber 17 to separate the output sampling light 6 passing through the electro-optical sampling chip 4 into two beams of light with orthogonal polarization directions, which are connected to the balanced photodetector 15.

[0098] Example 3

[0099] The novel terahertz topological insulator electro-optical sampling module provided by the present invention can be applied to measure terahertz electromagnetic waveform parameters. The following is a brief description of its application implementation process:

[0100] like Figure 5 As shown, a synchronous sampling and measurement system for terahertz electromagnetic waveform parameters includes:

[0101] Input terahertz electromagnetic wave 1, terahertz electromagnetic wave input port 2, first flexible dielectric waveguide 3, electro-optical sampling chip 4, input sampling light 5, output sampling light 6, second flexible dielectric waveguide 7, terahertz electromagnetic wave output port 8, matching load 9, Wollaston prism 13, femtosecond laser A20, optical fiber delay line 21, data acquisition and analysis module 22 and ultrafast pulse generator 23.

[0102] In the optical link part, the output light of the femtosecond laser A20 with a central wavelength of 1550nm, a pulse width of 100fs and a repetition frequency of 100MHz is divided into two beams after passing through the optical fiber beam splitter. One beam of excitation light is used to excite the ultrafast pulse generator 23 to generate a terahertz pulse signal, and the other beam of sampling light is used to input the sampling light 5 and incident on the electro-optical sampling chip 4 after passing through the optical fiber delay line 21.

[0103] The Wollaston prism 13 decomposes the output sampling light 6 whose polarization state changes after passing through the electro-optical sampling chip 4 into s-polarized light and p-polarized light, and connects to the balanced photodetector 15 to convert it into a current signal, and finally converts it into waveform data through the data acquisition and analysis module 22, thereby realizing real-time online measurement of the waveform parameters of the measured ultrafast pulse signal.

[0104] In the terahertz electromagnetic wave link part, the terahertz pulse signal 1 generated by ultrafast femtosecond light excitation is directly fed into the terahertz topological waveguide structure on the surface of the electro-optical sampling chip 4 through the terahertz electromagnetic wave input port 2 and the first flexible dielectric waveguide 3, completes low-loss and low-dispersion transmission on the surface of the electro-optical sampling chip 4, and then is output from the terahertz electromagnetic wave output port 8 through the second flexible dielectric waveguide 7 and is absorbed by the matching load 9.

[0105] like Figure 6 As shown, an asynchronous sampling and measurement system for terahertz electromagnetic waveform parameters includes:

[0106] Input terahertz electromagnetic wave 1, terahertz electromagnetic wave input port 2, first flexible dielectric waveguide 3, electro-optical sampling chip 4, input sampling light 5, output sampling light 6, second flexible dielectric waveguide 7, terahertz electromagnetic wave output port 8, matching load 9, Wollaston prism 13, femtosecond laser A20, optical fiber delay line 21, data acquisition and analysis module 22, ultrafast pulse generator 23 and femtosecond laser B24.

[0107] In the optical link part, the output light of the femtosecond laser B24 with a central wavelength of 1550nm, a pulse width of 100fs and a repetition frequency of 100MHz+1KHz is connected to the ultrafast pulse generator 23 to stimulate the generation of terahertz electromagnetic wave signals;

[0108] The input sampling light 5 output by the femtosecond laser A20 with a central wavelength of 1550nm, a pulse width of 100fs and a repetition frequency of 100MHz is incident on the electro-optical sampling chip 4, and then the output sampling light 6 whose polarization state changes after passing through the electro-optical sampling chip 4 is decomposed into s-polarized light and p-polarized light using a Wollaston prism 13, and connected to a balanced photodetector 15 to be converted into a current signal, and then converted into waveform data through a data acquisition and analysis module 22.

[0109] In the terahertz electromagnetic wave link part, the terahertz pulse signal 1 generated by ultrafast femtosecond light excitation is directly fed into the terahertz topological waveguide structure on the surface of the electro-optical sampling chip 4 through the terahertz electromagnetic wave input port 2 and the first flexible dielectric waveguide 3, and then output from the terahertz electromagnetic wave output port 8 through the second flexible dielectric waveguide 7 after completing low-loss and low-dispersion transmission on the surface of the electro-optical sampling chip 4, and is absorbed by the matching load 9; finally, the real-time online measurement of the waveform parameters of the measured ultrafast pulse signal is realized.

[0110] In the description of the present invention, it should be noted that the terms "upper", "lower", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present invention. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0111] It should also be noted that, in the description of the present invention, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0112] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the embodiments here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. An electro-optical sampling device based on a terahertz topological insulator, characterized in that: include: Terahertz electromagnetic wave link structure, electro-optical sampling chip, optical link structure and balanced photodetector, The terahertz electromagnetic wave link structure is used to realize the transmission of input terahertz electromagnetic waves and output terahertz electromagnetic waves; The optical link structure is used to realize the transmission of input sampling light and output sampling light; The electro-optic sampling chip is used to transmit the input terahertz electromagnetic wave in the terahertz topological waveguide structure on the surface of the electro-optic sampling chip to obtain the output terahertz electromagnetic wave; and is also used to generate an electro-optic effect between the input sampling light and the input terahertz electromagnetic wave in the electro-optic sampling chip to obtain the output sampling light; The balanced photodetector is used to convert the output sampling light into a current signal.

2. The device according to claim 1, characterized in that The propagation direction of the input sampling light is orthogonal to the transmission direction of the input terahertz electromagnetic wave; The propagation direction of the output sampling light is orthogonal to the transmission direction of the output terahertz electromagnetic wave.

3. The device according to claim 1, characterized in that The terahertz electromagnetic wave link structure includes a terahertz electromagnetic wave input port and a terahertz electromagnetic wave output port. The terahertz electromagnetic wave input port is used to transmit the input terahertz electromagnetic wave generated by the terahertz electromagnetic wave generator to the electro-optical sampling chip; The terahertz electromagnetic wave output port is used to output the terahertz electromagnetic wave.

4. The device according to claim 3, characterized in that The terahertz electromagnetic wave input port and the terahertz electromagnetic wave output port are interconnected with the electro-optical sampling chip through a flexible dielectric waveguide.

5. The device according to claim 4, characterized in that The terahertz electromagnetic wave link structure also includes a matching load, The matching load is connected to the terahertz electromagnetic wave output port and is used for absorbing the output terahertz electromagnetic wave to reduce reflection of the output terahertz electromagnetic wave.

6. The device according to claim 1, characterized in that The optical link structure includes a fiber-coupled structure or a spatial light transmission structure; The fiber-coupled structure is used to couple the input sampling light fiber to the electro-optical sampling chip. It is also used to separate the output sampling light into two beams of light with orthogonal polarization directions, and transmit them to the balanced photodetector; The spatial light transmission structure is used to adjust the direction and shape the input sampling light transmitted in the free space, and is also used to separate the output sampling light into two beams of orthogonal polarized light and transmit them to the balanced photodetector.

7. The device according to claim 6, characterized in that The spatial light transmission type optical link structure includes Polarizer, 1 / 2 wave plate, beam focusing and collimating system, 1 / 4 wave plate, Wollaston prism and reflector group, The polarizer, 1 / 2 wave plate and 1 / 4 wave plate are used to adjust the polarization state and polarization direction of the input sampling light so that it forms a first angle with the transmission direction of the terahertz electromagnetic wave in the electro-optical sampling chip; The beam focusing and collimating system is used to shape the input sampling light incident on the electro-optical sampling chip into parallel light; The Wollaston prism is used to separate the output sampling light transmitted through the electro-optical sampling chip into two beams of orthogonal polarized light. The reflector group is used to direct the separated orthogonal polarized light into the balanced photodetector.

8. The device according to claim 6, characterized in that The fiber-coupled structure includes a fiber-coupled chip cavity, an input single-mode polarization-maintaining lens fiber, an output single-mode polarization-maintaining lens fiber, and a fiber polarization beam splitter; The electro-optical sampling chip is placed in the fiber-coupled chip cavity; The fiber-coupled chip cavity is provided with fiber-coupled packaging holes on both sides of the cavity perpendicular to the surface of the electro-optical sampling chip, which are respectively an input fiber-coupled packaging hole and an output fiber-coupled packaging hole; The input single-mode polarization-maintaining lens optical fiber is used to inject the input sampling light into the electro-optical sampling chip through the input optical fiber coupling packaging hole. The output single-mode polarization-maintaining lens optical fiber is used to receive the output sampling light transmitted through the electro-optical sampling chip through the output optical fiber coupling packaging hole; The optical fiber polarization beam splitter is connected to the output single-mode polarization-maintaining lens optical fiber and is used to separate the output sampling light passing through the electro-optical sampling chip into two beams of light with orthogonal polarization directions.

9. The device according to claim 3, characterized in that The terahertz topological waveguide structure on the surface of the electro-optical sampling chip is obtained by laser drilling or dry etching semiconductor technology.

10. The device according to claim 1, characterized in that The electro-optical sampling chip is an electro-optical sampling chip with double-sided polishing of substrate material.

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