A power imaging method for high-power microwaves based on solid-state quantum spin

Abstract

This invention relates to the field of microwave power imaging technology, specifically to a power imaging method for high-power microwaves based on solid-state quantum spin. To address the problem of existing technologies' difficulty in achieving power imaging of high-power microwaves based on solid-state quantum spin, this invention provides a novel power imaging method for high-power microwaves based on solid-state quantum spin, comprising the following steps: 1) introducing local homologous microwaves; 2) obtaining correlated microwaves; 3) obtaining ODMR curves; 4) calculating the correlated microwave power; 5) inversely calculating the power of the microwave to be measured to obtain an image of the power of the microwave to be measured. The imaging method of this invention reduces microwave power by introducing correlated microwaves, effectively controlling the saturation effect of the full width at half maximum (FWHM) of the ODMR curve resonance peak caused by excessively high microwave power during fixed quantum spin microwave imaging detection, thereby achieving power imaging of high-power microwaves based on solid-state quantum spin.

Description

Technical Field

[0001] This invention relates to the field of microwave imaging technology, specifically to a power imaging method based on high-power microwaves using solid-state quantum spin. Background Technology

[0002] Microwave power imaging is an important tool for studying microwave power and its distribution, and it is widely used in electromagnetic field detection, microwave radiation safety monitoring, and microwave equipment performance evaluation. Traditional microwave field imaging methods mainly rely on radiation field sensors or near-field probes, but these methods suffer from trade-offs in detection speed, imaging field of view, and resolution. Existing technologies include superconducting quantum interference devices (SQIs), which can perform high-sensitivity microwave power detection within the microwave frequency range, but they require ultra-low temperature environments. While fiber optic sensor technology can operate over a wider temperature range, its resolution and sensitivity are still somewhat limited.

[0003] Currently, with the advancement of nitrogen-vacancy (NV) center technology, microwave power imaging based on NV centers is gradually becoming an effective method. NV centers not only operate at room temperature but also possess high sensitivity and a wide frequency response range, giving them an advantage in microwave power imaging. Existing technologies, such as NV center direct microwave power imaging, can achieve real-time, high-resolution imaging of microwave power by controlling the spin state of NV centers and combining it with optically detected magnetic resonance (ODMR) technology. However, this method is only suitable for power imaging of low-power microwaves with a power range of less than 100mW. When the microwave power is greater than or equal to 100mW, the full width at half maximum (FWHM) of the ODMR curve no longer changes linearly, and the response of solid-state quantum spin to microwave power becomes saturated, making it difficult to achieve direct power response imaging of high-power microwaves. Furthermore, the thermal effects introduced by high power cause a temperature-dependent frequency shift in the NV center resonance frequency, further limiting the realization of power imaging of high-power microwaves based on solid-state quantum spin. Summary of the Invention

[0004] In order to solve the problem that existing technologies are unable to achieve high-precision power imaging of high-power microwaves based on solid-state quantum spin, this invention provides a new power imaging method for high-power microwaves based on solid-state quantum spin.

[0005] This invention is achieved using the following technical solution:

[0006] A power imaging method for high-power microwaves based on solid-state quantum spin includes the following steps:

[0007] 1) Introducing local homogeneous microwaves:

[0008] magnetic field strength of the microwave to be measured

[0009] ①

[0010] in, The amplitude of the microwave magnetic field to be measured. Angular frequency, For time;

[0011] The magnetic field strength of the introduced local co-source microwave

[0012] ②

[0013] in, The initial phase difference between the microwave under test and the local microwave of the same origin;

[0014] The microwave power of the microwave under test and the local microwave of the same origin are both ;

[0015] 2) Obtain the associated microwave:

[0016] The magnetic field strength of the correlated microwave is obtained by adding the magnetic field strength of the microwave to be measured and the magnetic field strength of the local microwave of the same origin.

[0017] ③

[0018] in, To correlate the microwave magnetic field amplitude;

[0019] Since microwave power is proportional to the square of the microwave magnetic field amplitude, the microwave power of the microwave to be measured is...

[0020] ④

[0021] microwave power associated with microwaves

[0022] ⑤

[0023] Substituting formula ④ into formula ⑤, we get

[0024] ⑥

[0025] in, and ;

[0026] 3) Obtain the ODMR curve:

[0027] By using green laser to polarize NV color centers, and simultaneously scanning the associated microwave frequency and irradiating it onto the surface of the polarized NV color centers, the ODMR curve of fluorescence intensity and associated microwave power corresponding to each pixel can be obtained.

[0028] 4) Calculate the associated microwave power:

[0029] Full width at half maximum (FWHM) of the resonance peak in the ODMR curve Associated microwave power The relationship is as follows: ⑦

[0030] in, , These represent the longitudinal and transverse intrinsic relaxation times at room temperature, respectively. Represents the inherent coherence time of electron spin. Indicates the gyromagnetic ratio, Indicates the optical pump rate;

[0031] The full width at half maximum (FWHM) of the ODMR curve resonance peak corresponding to each pixel Substituting into formula ⑦ yields the associated microwave power for each pixel. ;

[0032] 5) Calculate the associated microwave power of each pixel obtained in step 4). Substituting into formula ⑥, we can deduce the microwave power to be measured corresponding to each pixel. This allows us to obtain a power imaging map of the microwave under test.

[0033] Explanation of principle: As can be seen from formula ⑥, when As the temperature increases from 0° to 120°, the associated microwave power increases from 4... Descending to This shows that when When the correlated microwave power is greater than the measured microwave power, and when When the angle increases from 120° to 180°, the associated microwave power decreases from... It drops to 0, therefore we know that when At that time, the correlated microwave power is less than the microwave power to be measured, so, in principle, Should be taken The value can be between [value] and [value], but which value to take depends on the actual microwave power of the microwave being measured. As long as the correlated microwave power obtained according to formula ⑥ is low power microwave, it is acceptable to avoid high power microwave causing microwave measurement of solid-state quantum spin to become saturated.

[0034] Furthermore, the initial phase difference between the microwave under test and the local microwave of the same origin. The value is From formula ⑥, we can see that... The closer the value is to 180°, the lower the associated microwave power, the larger the power range of the microwave under test that can be imaged, and the wider the applicability.

[0035] The beneficial effects of this invention are as follows: The imaging method described in this invention introduces local homologous microwaves through a microwave correlation measurement process, transforming the microwave to be measured into a correlated microwave interacting with the NV color center. This effectively controls the saturation effect of the full width at half maximum (FWHM) of the ODMR curve resonance peak caused by excessive microwave power during fixed quantum spin microwave imaging detection. This expands the power measurement range of solid-state quantum spin microwaves and realizes power imaging of high-power microwaves based on solid-state quantum spin. Attached Figure Description

[0036] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0037] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0038] Figure 1 This is a flowchart of the power imaging method for high-power microwaves described in this invention;

[0039] Figure 2 An image formed using the high-power microwave power imaging method described in this invention;

[0040] Figure 3 This is a power imaging image of a high-power microwave generated through finite element software simulation. Detailed Implementation

[0041] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0042] In this description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0043] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0044] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0045] like Figure 1 As shown, a power imaging method for high-power microwaves based on solid-state quantum spin includes the following steps:

[0046] 1) Introducing local homogeneous microwaves:

[0047] magnetic field strength of the microwave under test

[0048] ①

[0049] in, The amplitude of the microwave magnetic field to be measured. Angular frequency, For time;

[0050] The magnetic field strength of the introduced local co-source microwave

[0051] ②

[0052] in, The initial phase difference between the microwave under test and the local microwave of the same origin;

[0053] The microwave power of the microwave under test and the local microwave of the same origin are both ;

[0054] 2) Obtain the associated microwave:

[0055] The magnetic field strength of the correlated microwave is obtained by adding the magnetic field strength of the microwave to be measured and the magnetic field strength of the local microwave of the same origin.

[0056] ③

[0057] in, To correlate the microwave magnetic field amplitude;

[0058] Since microwave power is proportional to the square of the microwave magnetic field amplitude, the microwave power of the microwave to be measured is...

[0059] ④

[0060] microwave power associated with microwaves

[0061] ⑤

[0062] Substituting formula ④ into formula ⑤, we get

[0063] ⑥

[0064] in, and ;

[0065] 3) Obtain the ODMR curve:

[0066] The NV color center was polarized using a green laser, and the associated microwave frequency was scanned and irradiated onto the surface of the polarized NV color center. The ODMR curve of the fluorescence intensity and microwave frequency corresponding to each pixel was obtained from the image.

[0067] 4) Calculate the associated microwave power:

[0068] Full width at half maximum (FWHM) of the resonance peak in the ODMR curve Associated microwave power The relationship is as follows: ⑦

[0069] in, , These represent the longitudinal and transverse intrinsic relaxation times at room temperature, respectively. Represents the inherent coherence time of electron spin. Indicates the gyromagnetic ratio, Indicates the optical pump rate;

[0070] The full width at half maximum (FWHM) of the ODMR curve resonance peak corresponding to each pixel Substituting into formula ⑦ yields the associated microwave power for each pixel. ;

[0071] 5) Calculate the associated microwave power of each pixel obtained in step 4). Substituting into formula ⑥, we can deduce the microwave power to be measured corresponding to each pixel. This allows us to obtain a power image of the microwave under test.

[0072] Experimental verification: Power imaging of a loop microwave antenna;

[0073] In the experiment, the NV centers used were Ib-type single-crystal diamond samples obtained under high temperature and high pressure conditions, with a crystal orientation of

[100] . The concentration of the NV centers was approximately 3 ppm, and the initial phase angle of the introduced local co-source microwave was 179°. The power imaging obtained using the above imaging method is shown in the figure below. Figure 2 As shown, the power imaging diagram of the high-power microwave was obtained through finite element simulation, as shown in the figure. Figure 3 As shown in the figure, Figure 2 and Figure 3The results are largely consistent, proving that the high-power microwave power imaging method described in this invention is feasible and has high imaging accuracy.

[0074] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A power imaging method for high-power microwaves based on solid-state quantum spin, characterized in that, Includes the following steps: 1) Introducing local homogeneous microwaves: magnetic field strength of the microwave to be measured ① in, The amplitude of the microwave magnetic field to be measured. Angular frequency, For time; The magnetic field strength of the introduced local co-source microwave ② in, The initial phase difference between the microwave under test and the local microwave of the same origin; The microwave power of the microwave under test and the local microwave of the same origin are both ; 2) Obtain the associated microwave: The magnetic field strength of the correlated microwave is obtained by adding the magnetic field strength of the microwave to be measured and the magnetic field strength of the local microwave of the same origin. ③ in, To correlate the microwave magnetic field amplitude; Since microwave power is proportional to the square of the microwave magnetic field amplitude, the microwave power of the microwave to be measured is... ④ microwave power associated with microwaves ⑤ Substituting formula ④ into formula ⑤, we get ⑥ in, and ; 3) Obtain the ODMR curve: By using green laser to polarize NV color centers, and simultaneously scanning the associated microwave frequency and irradiating it onto the surface of the polarized NV color centers, the ODMR curve of fluorescence intensity and associated microwave power corresponding to each pixel can be obtained. 4) Calculate the associated microwave power Full width at half maximum (FWHM) of the resonance peak in the ODMR curve Associated microwave power The relationship is as follows: ⑦ in, , These represent the longitudinal and transverse intrinsic relaxation times at room temperature, respectively. Represents the inherent coherence time of electron spin. Indicates the gyromagnetic ratio, Indicates the optical pump rate; The full width at half maximum (FWHM) of the ODMR curve resonance peak corresponding to each pixel Substituting into formula ⑦ yields the associated microwave power for each pixel. ; 5) Calculate the associated microwave power of each pixel obtained in step 4). Substituting into formula ⑥, we can deduce the microwave power to be measured corresponding to each pixel. This allows us to obtain a power imaging map of the microwave under test.

2. The power imaging method for high-power microwaves based on solid-state quantum spin according to claim 1, characterized in that, Initial phase difference between the microwave under test and the local microwave of the same origin The value is .

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