A millimeter wave high-order frequency comb multiplier and its preparation method and application

Abstract

The present invention belongs to the field of millimeter wave frequency doubling technology, and provides a millimeter wave high-order frequency comb multiplier and its preparation method and application. The millimeter wave high-order frequency comb multiplier of the present invention comprises a stacked substrate layer and an absorption layer; the absorption layer comprises a niobium iridium telluride layer and a metal electrode layer, part of the metal electrode layer is overlapped on the niobium iridium telluride layer, and the four metal electrode layers are symmetrically distributed in the transverse and longitudinal directions. The present invention adopts niobium iridium telluride as the absorption layer, which is a zero-bandgap material with a wide detection spectrum range; at the same time, niobium iridium telluride is a non-centrosymmetric material with a large Berry curvature dipole coefficient, so that it has a nonlinear Hall effect induced by Berry curvature, so that the millimeter wave high-order frequency comb multiplier constructed therefrom has a high-order frequency doubling effect, and does not require an external bias voltage, and can work stably at room temperature and low temperature. In addition, the dependence on high-frequency millimeter wave-terahertz sources is effectively reduced, providing a theoretical basis for the development of high-frequency millimeter wave-terahertz sources.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter wave frequency sources, and in particular to a millimeter wave high-order frequency comb multiplier and a preparation method and application thereof. Background Art

[0002] Millimeter wave frequency sources refer to electronic devices used to generate millimeter wave frequency band signals. Currently, millimeter wave frequency sources are mainly implemented in the form of oscillators or frequency multiplication-amplification links. However, traditional millimeter wave oscillators (such as avalanche oscillators and Gunn oscillators) and frequency multiplication-amplification links face some challenges in millimeter wave frequency band applications: (1) At high frequencies, frequency drift and temperature changes of traditional millimeter wave oscillators may cause unstable output frequencies, and it is difficult to achieve low phase noise performance at high frequencies. In addition, the circuit structure of millimeter wave oscillators is complex and difficult to debug, which increases the difficulty of design and production and is not conducive to applications in modern society. (2) Although the frequency multiplication-amplification link can obtain millimeter wave frequency band signals with low phase noise, its structure is complex and easily affected by various factors (such as temperature, manufacturing process deviation, etc.), thereby reducing the stability of the system; at the same time, the frequency multiplication-amplification link is easily affected by inter-stage impedance matching and filtering problems, resulting in a decrease in overall performance. This is a problem of its own principle. Therefore, it is urgent to develop new technical ideas to provide higher performance, better stability and lower cost to meet the needs of modern millimeter wave systems.

[0003] At present, researchers from Pennsylvania State University have used the lock-in amplifier method to produce a cross-shaped device based on the first-type Weyl semimetal material niobium phosphide, and have achieved the second harmonic frequency doubling signal when a 1GHz signal is input. However, the frequency doubling order of this cross-shaped device is only 2 times. Summary of the invention

[0004] In view of this, the object of the present invention is to provide a millimeter wave high-order frequency comb multiplier and its preparation method and application. The millimeter wave high-order frequency comb multiplier of the present invention can achieve a high frequency multiplication order for millimeter waves.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a millimeter wave high-order frequency comb multiplier, comprising a base layer and an absorption layer stacked in layers;

[0007] The absorption layer includes a niobium, iridium and tellurium layer and a metal electrode layer. Part of the metal electrode layer overlaps the niobium, iridium and tellurium layer. The number of the metal electrode layers is 4, and the 4 metal electrode layers are symmetrically distributed in the transverse and longitudinal directions of the niobium, iridium and tellurium layer.

[0008] Preferably, the base layer comprises a substrate layer and an oxide layer which are stacked, and the oxide layer is in contact with the absorption layer.

[0009] Preferably, the substrate layer is made of silicon (Si), has a resistivity of 10000-20000 Ω·cm, and a thickness of 200-600 μm.

[0010] Preferably, the oxide layer is made of silicon dioxide (SiO2), and the thickness of the oxide layer is 200-500 nm.

[0011] Preferably, the thickness of the niobium, iridium and tellurium layer is 15-100 nm.

[0012] Preferably, the metal electrode layer comprises a chromium layer and a gold layer which are stacked, and the chromium layer is in contact with the niobium, iridium and tellurium layer.

[0013] Preferably, the thickness of the chromium layer is 5-25 nm, and the thickness of the gold layer is 45-100 nm.

[0014] The present invention also provides a method for preparing the millimeter wave high-order frequency comb multiplier described in the above technical solution, comprising the following steps:

[0015] Mechanically exfoliating the niobium, iridium and tellurium single crystals to obtain niobium, iridium and tellurium nanosheets;

[0016] transferring the niobium, iridium and tellurium nanosheets onto a substrate layer to form a niobium, iridium and tellurium layer;

[0017] Performing focused ion beam etching on the niobium, iridium and tellurium layer to obtain a metal electrode layer overlap structure;

[0018] A photoresist is coated on the metal electrode layer overlap structure, and then electron beam exposure, electron beam evaporation and stripping processes are sequentially performed to form a metal electrode layer to obtain the millimeter wave high-order frequency comb multiplier.

[0019] Preferably, the thickness of the niobium, iridium, and tellurium nanosheets is 15 to 100 nm.

[0020] The present invention also provides the use of the millimeter wave high-order frequency comb multiplier described in the above technical solution or the millimeter wave high-order frequency comb multiplier prepared by the preparation method described in the above technical solution in frequency doubling or mixing.

[0021] The invention provides a millimeter wave high-order frequency comb multiplier.

[0022] The millimeter wave high-order frequency comb multiplier of the present invention uses niobium iridium telluride (NbIrTe4) as the absorption layer. NbIrTe4 is a zero-bandgap material with a wide detection spectrum range. At the same time, NbIrTe4 is a non-centrosymmetric material with a large Berry curvature dipole coefficient, which makes it have a nonlinear Hall effect induced by Berry curvature, so that the millimeter wave high-order frequency comb multiplier constructed with NbIrTe4 has a high-order frequency multiplication effect, and does not require an external bias, and can work stably at room temperature and low temperature. In addition, this high-order frequency multiplication effect has the situation of even and odd times existing at the same time. The odd times are caused by the nonlinear acceleration of electrons, which is determined by the longitudinal in-band Bloch oscillation caused by the band velocity. The even-numbered high-order harmonics originate from the transverse Bloch oscillation caused by non-zero Berry curvature. Because NbIrTe4 has this strong intrinsic nonlinear high-order effect, when it is acted upon by two electromagnetic signals of different frequencies, the electronic response generated in NbIrTe4 will produce new frequency components, similar to the traditional heterodyne mixing effect. This nonlinear effect enables niobium, iridium and tellurium to play the role of heterodyne detection in signal detection and frequency conversion. Therefore, the millimeter-wave high-order frequency comb multiplier of the present invention can also be used for harmonic mixing heterodyne detection, effectively reducing the dependence on high-frequency local oscillator sources; in addition, the millimeter-wave high-order frequency comb multiplier of the present invention can be used for heterodyne imaging, as well as for the fields of unknown gas spectrum detection, and the millimeter-wave high-order frequency comb multiplier of the present invention can be expanded, with optimized circuit design, and compatible with CMOS technology. In the future, an integrated planar array can be prepared to solve many problems for focal plane imaging.

[0023] The data of the embodiment show that the millimeter wave high-order frequency comb multiplier of the present invention has at least 26 orders of frequency multiplication for millimeter waves; at the same time, the high-order frequency multiplication includes both odd and even orders. In addition, the millimeter wave high-order frequency comb multiplier of the present invention also has a mixing function. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A front view of the millimeter wave high-order frequency comb multiplier provided by the present invention;

[0025] Figure 2 A top view of the millimeter wave high-order frequency comb multiplier provided by the present invention;

[0026] Figure 3 A schematic diagram of a system for testing the frequency doubling performance of the millimeter wave high-order frequency comb multiplier of Example 1;

[0027] Figure 4 This is a frequency multiplication performance test data diagram of the millimeter wave high-order frequency comb multiplier of Example 1;

[0028] Figure 5 A schematic diagram of a system for performing harmonic mixing testing on the millimeter-wave high-order frequency comb multiplier of Example 1;

[0029] Figure 6 is a diagram showing the dependence of the high-order frequency multiplication output and input power of the millimeter-wave high-order frequency comb multiplier of Example 1;

[0030] Figure 7 The test data diagram of the third harmonic mixing of the millimeter-wave high-order frequency comb multiplier of Example 1 (left) and the dependence of the local oscillator input power on the intermediate frequency output power (right);

[0031] Figure 8 The test data diagram of the fourth harmonic mixing of the millimeter-wave high-order frequency comb multiplier of Example 1 (left) and the dependence of the local oscillator input power on the intermediate frequency output power (right);

[0032] Fig. 9 The test data diagram of the fifth harmonic mixing of the millimeter-wave high-order frequency comb multiplier of Example 1 (left) and the dependence of the local oscillator input power on the intermediate frequency output power edge (right);

[0033] Reference numerals: 1 - substrate layer, 2 - oxide layer, 3 - niobium iridium telluride layer, 4 - metal electrode layer. DETAILED DESCRIPTION

[0034] Glossary:

[0035] In the present invention, the cross-sectional shape of the niobium, iridium and tellurium thin sheet obtained by mechanically peeling the niobium, iridium and tellurium from the niobium, iridium and tellurium single crystal is rectangular, so the cross-sectional shape of the niobium, iridium and tellurium layer is rectangular, the transverse direction specifically refers to the short side of the niobium, iridium and tellurium layer, that is, the b-axis direction of the niobium, iridium and tellurium crystallography, and the longitudinal direction specifically refers to the long side of the niobium, iridium and tellurium layer, that is, the a-axis direction of the niobium, iridium and tellurium crystallography.

[0036] Figure 1 A front view of the millimeter wave high-order frequency comb multiplier provided by the present invention, Figure 2 A top view of the millimeter wave high-order frequency comb multiplier provided by the present invention is shown below in conjunction with Figure 1 and Figure 2 The structure of the millimeter wave high-order frequency comb multiplier provided by the present invention is described in detail.

[0037] The present invention provides a millimeter wave high-order frequency comb multiplier, comprising a base layer and an absorption layer stacked in layers;

[0038] The absorption layer includes a niobium, iridium and tellurium layer and a metal electrode layer. Part of the metal electrode layer overlaps the niobium, iridium and tellurium layer. The number of the metal electrode layers is 4, and the 4 metal electrode layers are symmetrically distributed in the transverse and longitudinal directions of the niobium, iridium and tellurium layer.

[0039] The millimeter wave high-order frequency comb multiplier provided by the present invention includes a base layer, and the base layer preferably includes a base layer and an oxide layer stacked, and the oxide layer is in contact with the absorption layer. In the present invention, the material of the base layer is preferably silicon (Si), and the resistivity of the base layer is preferably 10000~20000Ω·cm, and is preferably 10000Ω·cm, 15000Ω·cm or 20000Ω·cm; the thickness is preferably 200~600μm, and is preferably 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, 550μm or 600μm. In the present invention, the material of the oxide layer is preferably silicon dioxide (SiO2). In the present invention, the thickness of the oxide layer is preferably 200~500nm, and is preferably 200nm, 250nm, 300nm, 350nm, 400nm, 450nm or 500nm. In a specific embodiment of the present invention, the base layer is preferably a commercially available high-resistance silicon dioxide wafer. In a specific embodiment of the present invention, the cross-sectional shape of the base layer is preferably a rectangle, and the size of the rectangle is preferably 1 cm×1 cm.

[0040] The millimeter wave high-order frequency comb multiplier provided by the present invention includes an absorption layer stacked with the base layer, the absorption layer includes a niobium iridium telluride layer and a metal electrode layer, part of the metal electrode layer is overlapped on the niobium iridium telluride layer, the number of the metal electrode layers is 4, and the 4 metal electrode layers are symmetrically distributed in the transverse and longitudinal directions of the niobium iridium telluride layer.

[0041] In the present invention, the thickness of the niobium, iridium, and tellurium layer is preferably 15 to 100 nm, and more preferably 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, or 100 nm. In the present invention, the cross-sectional shape of the niobium, iridium, and tellurium layer is preferably a rectangle, and the size of the rectangle is preferably 5 to 40 μm × 5 to 100 μm, and more preferably 10 μm × 20 μm.

[0042] In the present invention, the metal electrode layer preferably includes a chromium layer and a gold layer stacked, and the chromium layer is preferably in contact with the niobium, iridium and tellurium layer. In the present invention, the thickness of the chromium layer is preferably 5 to 25 nm, and is particularly preferably 5 nm, 10 nm, 15 nm, 20 nm or 25 nm. In the present invention, the thickness of the gold layer is preferably 45 to 100 nm, and is particularly preferably 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm or 100 nm. In the present invention, the cross-sectional shape of the metal electrode layer is preferably a rectangle, and the size of the rectangle is preferably 2 to 10 μm × 50 to 150 μm, and more preferably 5 μm × 80 μm. In the present invention, the cross-sectional shape of the metal electrode layer in contact with the niobium, iridium and tellurium layer is preferably a rectangle, and the size of the rectangle is preferably 2 to 10 μm × 2 to 10 μm, and more preferably 5 μm × 2 μm.

[0043] In the present invention, when the cross-sectional shape of the NbIrTe layer is preferably rectangular and the cross-sectional shape of the metal electrode layer is preferably rectangular, the long side of the metal electrode layer preferably crosses perpendicularly with the side of the NbIrTe layer in contact therewith.

[0044] The present invention also provides a method for preparing the millimeter wave high-order frequency comb multiplier described in the above technical solution, comprising the following steps:

[0045] Mechanically exfoliating the niobium, iridium and tellurium single crystals to obtain niobium, iridium and tellurium nanosheets;

[0046] transferring the niobium, iridium and tellurium nanosheets onto a substrate layer to form a niobium, iridium and tellurium layer;

[0047] Performing focused ion beam etching on the niobium, iridium and tellurium layer to obtain a metal electrode layer overlap structure;

[0048] The metal electrode layer overlap structure is coated with photoresist, and then electron beam exposure, electron beam evaporation and stripping processes are sequentially performed to form a metal electrode layer to obtain the millimeter wave high-order frequency comb multiplier.

[0049] Unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

[0050] The present invention mechanically exfoliates the niobium, iridium and tellurium single crystals to obtain niobium, iridium and tellurium nanosheets.

[0051] In the present invention, the mechanical peeling tool is preferably a blue tape. In the present invention, the thickness of the niobium, iridium, and tellurium nanosheets is preferably 15 to 100 nm.

[0052] After obtaining the niobium, iridium and tellurium nanosheets, the present invention transfers the niobium, iridium and tellurium nanosheets to the substrate layer to form a niobium, iridium and tellurium layer.

[0053] The present invention does not specifically limit the transfer operation, and operations well known to those skilled in the art may be used.

[0054] After forming the niobium, iridium and tellurium layer, the present invention performs focused ion beam etching on the niobium, iridium and tellurium layer to obtain a metal electrode layer overlap structure.

[0055] The present invention does not specifically limit the parameters of the focused ion beam etching, as long as the metal electrode layer overlapping structure can be obtained.

[0056] After obtaining the metal electrode layer overlapping structure, the present invention coats photoresist on the metal electrode layer overlapping structure, and then sequentially uses electron beam exposure, electron beam evaporation and stripping processes to form a metal electrode layer to obtain the millimeter wave high-order frequency comb multiplier.

[0057] The present invention does not specifically limit the photoresist coating, electron beam exposure, electron beam evaporation and stripping processes, and operations well known to those skilled in the art may be adopted.

[0058] The present invention also provides the use of the millimeter wave high-order frequency comb multiplier described in the above technical solution or the millimeter wave high-order frequency comb multiplier prepared by the preparation method described in the above technical solution in frequency doubling or mixing.

[0059] The present invention does not specifically limit the application of the millimeter-wave high-order frequency comb multiplier, and those skilled in the art may configure it according to actual needs.

[0060] The millimeter wave high-order frequency comb multiplier provided by the present invention and its preparation method and application are described in detail below in conjunction with the embodiments, but they should not be understood as limiting the protection scope of the present invention.

[0061] Example 1

[0062] according to Figure 1 and Figure 2 A millimeter wave high-order frequency comb multiplier is provided, with specific parameters as follows: the material of the substrate layer is silicon (Si), the resistivity is 20000Ω·cm, the thickness is 500μm, and the size of the cross-section is 1cm×1cm; the material of the oxide layer is silicon oxide (SiO2), the thickness is 300nm, and the size of the cross-section is 1cm×1cm; the thickness of the niobium iridium telluride layer is 70nm, and the size of the cross-section is 10μm×20μm; in the metal electrode layer, the thickness of the chromium layer is 15nm, the thickness of the gold layer is 75nm, and the size of the cross-section of the metal electrode layer is 5μm×80μm; the overlap size of the niobium iridium telluride layer and the metal electrode layer is 5μm×2μm.

[0063] The specific preparation method is as follows: mechanically exfoliate the niobium, iridium and tellurium single crystals to obtain niobium, iridium and tellurium nanosheets; transfer the niobium, iridium and tellurium nanosheets to the substrate layer to form an absorption layer; perform focused ion beam etching on the absorption layer to obtain a metal electrode layer overlap structure; apply photoresist on the metal electrode layer overlap structure, and then sequentially perform electron beam exposure, electron beam evaporation and stripping steps to form a metal electrode layer to obtain a millimeter wave high-order frequency comb multiplier.

[0064] (1) The frequency multiplication performance of the millimeter-wave high-order frequency comb multiplier of Example 1 was tested.

[0065] according to Figure 3 The system schematic diagram shown in FIG. 1 is to irradiate the millimeter wave frequency band beam vertically onto the a-axis (a and b are perpendicular to each other) of the niobium iridium telluride crystal in the millimeter wave high-order frequency comb multiplier of Example 1 through a linear polarizer. The result is as follows Figure 4 As shown, Figure 4 This is a test data diagram of the frequency multiplication performance of the millimeter wave high-order frequency comb multiplier of Example 1, from Figure 4 It can be seen that: due to the existence of a slip mirror axis on the a-axis of niobium, iridium and tellurium crystallography , and the crystallographic b-axis has a mirror symmetry axis Ma, so this low symmetry exists on the top and bottom surfaces of NbIrTe, resulting in a non-zero Berry curvature dipole D ac . Therefore, in the absence of an external magnetic field, the electromagnetic wave along the a-axis will generate a nonlinear Hall voltage along the b-axis. This provides theoretical support for the generation of high-order harmonic signals in niobium, iridium and telluride. By connecting the b-axis to the spectrum analyzer through the three-phase connector SMA for analysis, the output power signal of the high-order harmonic can be obtained. In addition, the high-order harmonics include both odd and even orders. For example: set the millimeter wave input frequency to 1GHz, at this time, at least 26-order frequency comb signals can be obtained in the spectrum analyzer. The same is true for inputs of 6, 8, and 10GHz. In addition, after transforming the millimeter wave input power, according to the dependence of the output power of the high-order harmonics on the input power, it is concluded that the high-order harmonics in niobium, iridium and telluride are non-perturbative nonlinear optics. In the traditional perturbation theory of nonlinear optics, only odd-order harmonic harmonics exist in low-symmetry systems. And the output power strongly depends on the power of the input power. The present invention is far different from traditional perturbation nonlinear optics, which proves the innovativeness of the working mechanism of the niobium iridium telluride high-order frequency comb doubler, and confirms that the odd harmonics are caused by the nonlinear acceleration of electrons, which is determined by the longitudinal intra-band Bloch oscillation caused by the band velocity. The even harmonics originate from the transverse Bloch oscillation caused by the non-zero Berry curvature. In addition, since the b-axis of niobium iridium telluride is a mirror axis, when the millimeter wave is applied along the transverse b-axis, the high-order harmonic effect obtained at the longitudinal a-axis is much smaller than that when the millimeter wave is applied at the a-axis, the high-order harmonic signal received at the b-axis is basically zero, realizing the experimental observation of the high-order harmonics of niobium iridium telluride (NbIrTe4).

[0066] (2) Perform a harmonic mixing test on the millimeter-wave high-order frequency comb multiplier of Example 1.

[0067] The millimeter wave high-order frequency comb multiplier of the present invention also has a heterodyne mixing function; by using the millimeter wave high-order frequency comb multiplier of embodiment 1 as a local oscillator source, the burden required for high-frequency and broadband local oscillator sources is effectively reduced, and the radio frequency band bandwidth of the heterodyne receiver is increased to an unprecedented level. Figure 5 ( Figure 5 The test is performed using the system schematic diagram shown in the system schematic diagram for performing harmonic mixing test on the millimeter wave high-order frequency comb multiplier of Example 1, Figure 5 In the embodiment, the mixer is the millimeter wave high-order frequency comb multiplier of Example 1.

[0068] The specific process is as follows: a beam of millimeter wave light source is irradiated on the a-axis of niobium, iridium and tellurium in the millimeter wave high-order frequency comb multiplier of Example 1 after passing through a polarizer, and is used as a local oscillator source after high-order frequency multiplication; another beam of radio frequency source is irradiated on the a-axis of niobium, iridium and tellurium in the millimeter wave high-order frequency comb multiplier of Example 1 after passing through a polarizer, and the niobium, iridium and tellurium b-axis in the millimeter wave high-order frequency comb multiplier of Example 1 is connected to a spectrum analyzer after passing through a low-noise amplifier to obtain an intermediate frequency signal after subharmonic mixing f IF = f RF -n f LO , where n=1, 2, 3….

[0069] The results are as follows Figure 6~Figure 9 . Figure 6 is a diagram showing the dependence of the high-order frequency multiplication output and input power of the millimeter-wave high-order frequency comb multiplier of Example 1, from Figure 6 It can be seen that the slope relationship between the power and input power of the 24-27th order high-order harmonic output signal is 3.2±0.06, 2.7±0.05, 2.6±0.13, 2.9±0.08, respectively, which is obviously different from the slope relationship between the output power and input power of the traditional perturbation non-optics. The slope relationship of the 24-27th order is 24, 25, 26, 27. This shows that the present invention is far different from the traditional perturbation nonlinear optics, which proves the innovativeness of the working mechanism of the niobium iridium telluride high-order frequency comb doubler, and confirms that the odd-numbered harmonics are caused by the nonlinear acceleration of electrons, which is determined by the longitudinal intra-band Bloch oscillation caused by the band velocity. The even-numbered harmonics originate from the transverse Bloch oscillation caused by the non-zero Berry curvature.

[0070] Figure 7The test data diagram of the third harmonic mixing of the millimeter wave high-order frequency comb multiplier of Example 1 (left) and the dependence of the local oscillator input power on the intermediate frequency output power (right) are shown. Figure 7 It can be seen that: at this time the local oscillator source is f LO =27GHz, after the third harmonic 3 f LO =81GHz and RF source f RF =85.5GHz heterodyne, get the intermediate frequency signal f IF =4.5GHz, measured data as Figure 7 In addition, the slope relationship of the experimental data of the local oscillator input power and the intermediate frequency output power is 2.78±0.05, which is obviously not equal to the theoretical slope relationship.

[0071] Figure 8 The test data of the fourth harmonic mixing of the millimeter wave high-order frequency comb multiplier of Example 1 (left) and the dependence of the local oscillator input power on the intermediate frequency output power (right) are shown. Figure 8 It can be seen that: at this time the local oscillator source is f LO =22GHz, after the fourth harmonic 4 f LO =88GHz and RF source f RF =83.5 GHz heterodyne, get the intermediate frequency signal f IF =4.5GHz, measured data as Figure 8 In addition, the slope relationship between the experimental data of the local oscillator input power and the intermediate frequency output power is 3.5±0.38, which is obviously not equal to the theoretical slope relationship.

[0072] Fig. 9 The test data of the fifth harmonic mixing of the millimeter-wave high-order frequency comb multiplier of Example 1 (left) and the dependence of the intrinsic input power on the intermediate frequency output power edge (right) are shown. Fig. 9 It can be seen that: at this time the local oscillator source is f LO =18GHz, after the fifth harmonic 5 f LO =90 GHz and RF source f RF =86.7 GHz heterodyne, get the intermediate frequency signal f IF =3.3GHz, measured data as Fig. 9In addition, the slope relationship of the experimental data of the local oscillator input power and the intermediate frequency output power is 3.15±0.41, which is obviously not equal to the theoretical slope relationship.

[0073] In summary, the high-order frequency mixing of the millimeter-wave high-order frequency comb multiplier of the present invention is non-perturbative nonlinear optics, and realizes the application of high-order harmonic mixing in the terahertz band for the first time.

[0074] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A millimeter wave high-order frequency comb multiplier, comprising a stacked substrate layer and an absorption layer; The absorption layer includes a niobium, iridium and tellurium layer and a metal electrode layer, a portion of the metal electrode layer is overlapped on the niobium, iridium and tellurium layer, the number of the metal electrode layers is 4, and the 4 metal electrode layers are symmetrically distributed in the transverse and longitudinal directions of the niobium, iridium and tellurium layer; The thickness of the niobium, iridium and tellurium layer is 15-100 nm.

2. The millimeter wave high-order frequency comb multiplier according to claim 1, characterized in that: The base layer includes a substrate layer and an oxide layer which are stacked, and the oxide layer is in contact with the absorption layer.

3. The millimeter wave high-order frequency comb multiplier according to claim 2, characterized in that: The substrate layer is made of silicon, has a resistivity of 10000-20000 Ω·cm, and a thickness of 200-600 μm.

4. The millimeter wave high-order frequency comb multiplier according to claim 2, characterized in that: The material of the oxide layer is silicon dioxide, and the thickness of the oxide layer is 200-500nm.

5. The millimeter wave high-order frequency comb multiplier according to claim 1, characterized in that: The metal electrode layer includes a chromium layer and a gold layer which are stacked, and the chromium layer is in contact with the niobium, iridium and tellurium layer.

6. The millimeter wave high-order frequency comb multiplier according to claim 5, characterized in that: The thickness of the chromium layer is 5-25 nm, and the thickness of the gold layer is 45-100 nm.

7. The method for preparing the millimeter wave high-order frequency comb multiplier according to any one of claims 1 to 6, characterized in that: The following steps are involved: Mechanically exfoliating the niobium, iridium and tellurium single crystals to obtain niobium, iridium and tellurium nanosheets; transferring the niobium, iridium and tellurium nanosheets onto a substrate layer to form a niobium, iridium and tellurium layer; Performing focused ion beam etching on the niobium, iridium and tellurium layer to obtain a metal electrode layer overlap structure; A photoresist is coated on the metal electrode layer overlap structure, and then electron beam exposure, electron beam evaporation and stripping processes are sequentially performed to form a metal electrode layer to obtain the millimeter wave high-order frequency comb multiplier.

8. The preparation method according to claim 7, characterized in that: The thickness of the niobium, iridium and tellurium nanosheets is 15-100 nm.

9. Application of the millimeter wave high-order frequency comb multiplier according to any one of claims 1 to 6 in frequency multiplication or mixing.

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