Local oscillator adding device and method for heterodyne Rydberg atomic detection system

Abstract

The present application relates to a local oscillator adding device and method applied to a heterodyne Rydberg atomic detection system, wherein the local oscillator adding device includes a microwave signal source, a microwave isolation module, a local oscillator radiation structure, a resonance enhancement structure, a microwave absorption structure and a first matching load. The microwave signal source is used to generate a local oscillator signal and send it to the microwave isolation module, and the microwave isolation module is used to send the local oscillator signal to the local oscillator radiation structure and isolate the reflected signal of the local oscillator radiation structure. The local oscillator radiation structure is used to transmit the local oscillator signal to the resonance enhancement structure through spatial coupling, the resonance enhancement structure is used to resonate and enhance the local oscillator signal at the atomic gas chamber and the signal to be measured, the microwave absorption structure is used to convert the enhanced signal transmitted from the resonance enhancement structure through spatial coupling into a guided electromagnetic signal, and the first matching load is used to absorb the guided electromagnetic signal. The purpose of having strong applicability in practical engineering applications is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of atomic detection, and relates to a local oscillator adding device and method applied to a heterodyne Rydberg atomic detection system. Background Art

[0002] With the continuous development of detection technology, microwave detection technology has also achieved unprecedented development, and the depth and breadth of application have been significantly expanded. Since Rydberg atoms have extremely large polarizability and microwave transition dipole moment, they are extremely sensitive to external electromagnetic fields. Therefore, the new quantum microwave detection technology based on Rydberg atoms can break through the bandwidth and sensitivity limitations of traditional electronic detection technology and achieve ultra-wideband non-destructive and traceable microwave precision measurement.

[0003] Rydberg atom heterodyne technology is an important means to improve the sensitivity of Rydberg atom detection. In the traditional Rydberg atom heterodyne technology, there has been a Rydberg atom superheterodyne receiver that improves the detection sensitivity by adding a local oscillator microwave field. In addition to the Rydberg atom heterodyne technology, combining an atomic gas chamber with a microwave resonant cavity is also a means to improve the detection sensitivity, but this method cannot be applied to a heterodyne Rydberg atom detection system. However, in the process of realizing the present invention, the inventor found that the traditional Rydberg atom heterodyne technology has a technical problem of poor applicability in practical engineering applications. Summary of the invention

[0004] In view of the problems existing in the above-mentioned traditional methods, the present invention proposes a local oscillator adding device for a heterodyne Rydberg atomic detection system, a Rydberg atomic detection system and a design method for a local oscillator adding device for a heterodyne Rydberg atomic detection system, which has strong applicability in practical engineering applications.

[0005] In order to achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] On the one hand, a local oscillator adding device for a heterodyne Rydberg atomic detection system is provided, comprising a microwave signal source, a microwave isolation module, a local oscillator radiation structure, a resonance enhancement structure, a microwave absorption structure and a first matching load; the microwave signal source is used to generate a local oscillator signal and send it to the microwave isolation module, and the microwave isolation module is used to send the local oscillator signal to the local oscillator radiation structure and isolate the reflected signal of the local oscillator radiation structure;

[0007] The local oscillator radiation structure is used to transmit the local oscillator signal to the resonance enhancement structure through spatial coupling. The resonance enhancement structure is used to resonate and enhance the local oscillator signal and the signal to be measured at the atomic gas chamber. The microwave absorption structure is used to convert the enhanced signal transmitted from the resonance enhancement structure through spatial coupling into a guided electromagnetic signal. The first matching load is used to absorb the guided electromagnetic signal.

[0008] In one embodiment, the microwave isolation module includes a microwave circulator and a second matching load;

[0009] The microwave circulator is used to send the local oscillator signal into the local oscillator radiation structure and send the isolated reflected signal into the second matching load for absorption.

[0010] In one embodiment, the local oscillator radiation structure includes a first microwave connector and a first electromagnetic wave guiding structure;

[0011] The first microwave connector is connected to the local oscillator signal in the microwave circulator and sent to the first electromagnetic wave guiding structure. The first electromagnetic wave guiding structure converts the input local oscillator signal into a spatial radiation electromagnetic wave and guides it to the resonance enhancement structure.

[0012] In one of the embodiments, the first electromagnetic wave guiding structure includes a rectangular waveguide, a parallel plate waveguide or a microwave antenna.

[0013] In one embodiment, the microwave absorbing structure includes a second microwave joint and a second electromagnetic wave guiding structure;

[0014] The second electromagnetic wave guiding structure converts the space radiation electromagnetic wave transmitted from the resonance enhancement structure through space coupling into a guided electromagnetic signal and sends it to the second microwave connector. The second microwave connector sends the input guided electromagnetic signal to the first matching load for absorption.

[0015] In one of the embodiments, the second electromagnetic wave guiding structure includes a rectangular waveguide, a parallel plate waveguide or a microwave antenna.

[0016] In one embodiment, the resonance enhancement structure is an open resonant structure.

[0017] In one embodiment, the open resonant structure includes a first pole plate, a second pole plate, a first connecting portion and a second connecting portion, the first electromagnetic wave guiding structure includes a third pole plate and a fourth pole plate, and the second electromagnetic wave guiding structure includes a fifth pole plate and a sixth pole plate;

[0018] The first electrode plate and the second electrode plate are parallel and arranged opposite to each other, the third electrode plate and the fourth electrode plate are parallel and arranged opposite to each other, the fifth electrode plate and the sixth electrode plate are parallel and arranged opposite to each other, the third electrode plate, the second electrode plate and the fifth electrode plate are collinear and structurally connected in sequence, the first connecting portion structurally connects the first electrode plate and the third electrode plate, and the second connecting portion structurally connects the first electrode plate and the fifth electrode plate;

[0019] The fourth electrode plate and the sixth electrode plate are both located in an open resonant cavity surrounded by the first electrode plate, the first connecting portion, the third electrode plate, the second electrode plate, the fifth electrode plate and the second connecting portion.

[0020] In one embodiment, the resonance enhancement structure is used to be embedded in the atomic gas cell or the resonance enhancement structure is used to accommodate the atomic gas cell.

[0021] In one embodiment, the first matching load includes a waveguide matching load or a three-plate line matching load, and the second matching load includes a waveguide matching load or a three-plate line matching load.

[0022] On the other hand, there is also provided a Rydberg atom detection system, comprising an atomic gas chamber, a laser, a photoelectric detector, a signal processing device and the above-mentioned local oscillator adding device;

[0023] The laser is used to output laser to the atomic gas chamber, and the local oscillator adding device is used to add a local oscillator signal to the atomic gas chamber, and to resonate and enhance the local oscillator signal at the atomic gas chamber and the signal to be measured;

[0024] The photoelectric detector is used to detect the atomic spectrum in the atomic gas chamber and convert it into an electrical signal and output it to the signal processing device. The signal processing device is used to process the electrical signal to obtain detection information.

[0025] In another aspect, a method for designing a local oscillator adding device for a heterodyne Rydberg atomic detection system is provided, which is applied to the local oscillator adding device. The method comprises:

[0026] Determine the structural forms of the local oscillator radiation structure and the microwave absorption structure according to the frequency of the microwave to be detected;

[0027] According to the structure and size parameters of the atomic gas chamber, the combination form of the resonance enhancement structure and the atomic gas chamber and the size parameters of the resonance enhancement structure are determined;

[0028] According to the size parameters of the resonance enhancement structure, the maximum resonance enhancement factor when there is no local oscillator radiation structure and microwave absorption structure is obtained;

[0029] According to the maximum resonance enhancement factor and the set detection sensitivity, the spatial coupling coefficient is determined; the spatial coupling coefficient includes the spatial coupling coefficient between the resonance enhancement structure and the local oscillator radiation structure, and the spatial coupling coefficient between the resonance enhancement structure and the microwave absorption structure;

[0030] According to the spatial coupling coefficient, the size parameters of the local oscillator radiation structure and the microwave absorption structure are determined, and the design result data of the local oscillator adding device are output.

[0031] One of the above technical solutions has the following advantages and beneficial effects:

[0032] The above-mentioned local oscillator adding device and method applied to the heterodyne Rydberg atomic detection system, for the heterodyne Rydberg atomic detection system, realizes the addition of the local oscillator signal to the atomic gas chamber by providing a new local oscillator adding device, wherein the signal energy transmission is carried out through spatial coupling between the local oscillator radiation structure, the resonance enhancement structure and the microwave absorption structure, so that the physical size of the device is comparable to the physical size of the atomic gas chamber, firstly, the microwave signal source generates a local oscillator signal and sends it to the local oscillator radiation structure through the microwave isolation module, and then the local oscillator radiation structure converts the local oscillator signal into a spatial radiation electromagnetic wave, so as to send the local oscillator signal to the resonance enhancement structure through spatial coupling, and the resonance enhancement structure has a resonance enhancement effect on the local oscillator signal and the incoming wave signal at the atomic gas chamber, and the spatial radiation electromagnetic wave on the side of the resonance enhancement structure relative to the local oscillator radiation structure is sent to the first matching load after passing through the microwave absorption structure to be absorbed.

[0033] Compared with traditional technologies, the local oscillator adding device can add a local oscillator field to the Rydberg atomic detection system in a small space comparable to the physical size of the atomic gas chamber, and achieve the enhancement effect of the local oscillator signal and the incoming wave signal. While improving the detection sensitivity, it greatly enhances the miniaturization and engineering practicality of the Rydberg atomic detection system, achieving the purpose of having strong applicability in actual engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 A first structural schematic diagram of a local oscillator adding device applied to a heterodyne Rydberg atomic detection system in one embodiment;

[0036] Figure 2 A second structural schematic diagram of a local oscillator adding device applied to a heterodyne Rydberg atomic detection system in one embodiment;

[0037] Figure 3 A third structural schematic diagram of a local oscillator adding device applied to a heterodyne Rydberg atomic detection system in one embodiment;

[0038] Figure 4 A fourth structural schematic diagram of a local oscillator adding device applied to a heterodyne Rydberg atomic detection system in one embodiment;

[0039] Figure 5A top view of a structure in which a local oscillator radiation structure, a microwave absorption structure and a resonance enhancement structure are integrated in one embodiment;

[0040] Figure 6 A schematic diagram of the structure of a Rydberg atomic detection system in one embodiment;

[0041] Figure 7 A schematic diagram of a design process of a local oscillator adding device applied to a heterodyne Rydberg atomic detection system in one embodiment;

[0042] Figure 8 It is a schematic diagram of simulation results of resonance enhancement multiple when there is no local oscillation signal in one embodiment;

[0043] Fig. 9 A schematic diagram of a reflection coefficient simulation result of a local oscillator signal in one embodiment;

[0044] Fig.10 It is a schematic diagram of the simulation result of the resonance enhancement factor when a local oscillator signal is added in one embodiment. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0047] It should be noted that the reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The presentation of the phrase at various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0048] Those skilled in the art will appreciate that the embodiments described herein may be combined with other embodiments. The term "and / or" used in the present specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0049] The traditional Rydberg atom superheterodyne receiver increases the measurement sensitivity from a few μVcm to -1 Hz -1 / 2 Increased to 55nVcm -1 Hz-1 / 2 The inventor found in the study that this design adds the local oscillator field to the Rydberg atoms by means of space irradiation. During the experiment, the local oscillator field mouth surface is 1.5m away from the atomic gas chamber, which is much larger than the size of the atomic gas chamber itself (5cm), and the local oscillator field propagation path is easily interfered by the multipath effect caused by environmental scattering. Therefore, the local oscillator field addition method of space irradiation limits the application of the Rydberg atom detection system in actual engineering.

[0050] In addition to the Rydberg atom heterodyne technology, combining the atomic gas chamber with a microwave resonant cavity is also a means of improving detection sensitivity. However, this method can only add the local oscillator field through space irradiation. Therefore, this structure cannot be applied to the heterodyne Rydberg atom detection system.

[0051] Based on this, the present application aims at the technical problem of poor applicability of the above-mentioned traditional Rydberg atomic heterodyne technology in practical engineering applications, and provides a local oscillator adding device for a heterodyne Rydberg atomic detection system, which can add a local oscillator field to the Rydberg atomic detection system in a small space comparable to the physical size of the atomic gas chamber, thereby achieving an incoming signal enhancement effect, improving the detection sensitivity, and at the same time greatly improving the miniaturization and engineering practicality of the Rydberg atomic detection system, and has strong applicability in practical engineering applications.

[0052] The following will describe the implementation of the present invention in detail with reference to the accompanying drawings in the embodiment diagram of the present invention.

[0053] See also Figure 1 In one embodiment, the embodiment of the present application provides a local oscillator adding device 100 for a heterodyne Rydberg atomic detection system, comprising a microwave signal source 11, a microwave isolation module 12, a local oscillator radiation structure 13, a resonance enhancement structure 14, a microwave absorption structure 15 and a first matching load 16. The microwave signal source 11 is used to generate a local oscillator signal and send it to the microwave isolation module 12. The microwave isolation module 12 is used to send the local oscillator signal to the local oscillator radiation structure 13 and isolate the reflected signal of the local oscillator radiation structure 13. The local oscillator radiation structure 13 is used to transmit the local oscillator signal to the resonance enhancement structure 14 through spatial coupling. The resonance enhancement structure 14 is used to resonate and enhance the local oscillator signal at the atomic gas chamber and the signal to be measured. The microwave absorption structure 15 is used to convert the enhanced signal transmitted from the resonance enhancement structure 14 through spatial coupling into a guided electromagnetic signal. The first matching load 16 is used to absorb the guided electromagnetic signal.

[0054] It can be understood that the propagation path of the local oscillator signal can be: after the microwave signal source 11 generates the required local oscillator signal, it is sent to the microwave isolation module 12. The microwave isolation module 12 can be a microwave component in the art with microwave signal transmission and reflection isolation functions. The microwave isolation module 12 transmits the input local oscillator signal to the local oscillator radiation structure 13, and prevents the reflected signal caused by the mismatch between the local oscillator radiation structure 13 and the microwave isolation module 12 from entering the microwave signal source 11 and causing damage to the microwave signal source 11. After the local oscillator signal of the microwave isolation module 12 is sent to the local oscillator radiation structure 13, the local oscillator radiation structure 13 converts the local oscillator signal in the form of a guided electromagnetic wave into a spatial radiation electromagnetic wave, so that the local oscillator signal in the form of a spatial radiation electromagnetic wave can enter the resonance enhancement structure 14 through spatial coupling.

[0055] The resonance enhancement structure 14 is a resonance component with an incoming wave enhancement effect. The resonance enhancement structure 14 has a resonance enhancement effect on the local oscillator signal coupled from the space at the atomic gas chamber, thereby achieving the addition and enhancement of the local oscillator signal of the atomic gas chamber. Correspondingly, the resonance enhancement structure 14 is a structure with an open space, which can receive the signal to be measured in the space. In some embodiments, the atomic gas chamber can be embedded in the resonance enhancement structure 14 according to the size and shape of the atomic gas chamber, or the resonance enhancement structure 14 can also be embedded in the atomic gas chamber, as long as the above-mentioned required local oscillator signal addition and incoming wave signal resonance enhancement effects can be achieved.

[0056] For the incoming wave signal (i.e., the signal to be measured), after the signal to be measured in the space enters the resonance enhancement structure 14, the resonance enhancement structure 14 also has a resonance enhancement effect on the signal to be measured at the atomic gas chamber. The enhanced signal will be detected and processed in real time by the system's photoelectric detector. A part of the signal enters the local oscillator radiation structure 13 through space coupling in the form of space radiation electromagnetic waves. The local oscillator radiation structure 13 converts this part of the signal into a guided electromagnetic wave and sends it to the microwave isolation module 12 for absorption. The other part of the enhanced signal enters the microwave absorption structure 15 through space coupling in the form of space radiation electromagnetic waves. The microwave absorption structure 15 can be a microwave component with microwave signal transmission and conversion functions in the art. The microwave absorption structure 15 converts the incoming space radiation electromagnetic wave into a guided electromagnetic wave and sends it to the first matching load 16 for absorption. The first matching load 16 can be various types of matching loads already available in the art, and can be specifically selected according to the signal absorption needs of the device.

[0057] In some embodiments, the microwave absorption structure 15 and the local oscillator radiation structure 13 adopt the same structural design, so as to better ensure the uniformity of the electric field intensity at the atomic gas chamber and achieve a more accurate measurement effect. Figure 1As shown in the figure, the dotted line connection represents the signal propagation link of spatial coupling, and the solid line represents the propagation link of the guided electromagnetic wave. The same link parts in other figures below shall be understood in the same way.

[0058] The local oscillator adding device 100 applied to the heterodyne Rydberg atomic detection system is used for the heterodyne Rydberg atomic detection system. A new local oscillator adding device is provided to realize the addition of the local oscillator signal to the atomic gas chamber, wherein the signal energy transmission is performed between the local oscillator radiation structure 13, the resonance enhancement structure 14 and the microwave absorption structure 15 through spatial coupling, so that the physical size of the device is comparable to the physical size of the atomic gas chamber. First, the microwave signal source 11 generates a local oscillator signal which is sent to the local oscillator radiation structure 13 through the microwave isolation module 12, and then the local oscillator radiation structure 13 converts the local oscillator signal into a spatially radiated electromagnetic wave, and then sends the local oscillator signal to the resonance enhancement structure 14 through spatial coupling. The resonance enhancement structure 14 has a resonance enhancement effect on the local oscillator signal and the incoming wave signal at the atomic gas chamber, and the spatially radiated electromagnetic wave on the side of the resonance enhancement structure 14 relative to the local oscillator radiation structure 13 is sent to the first matching load 16 for absorption after passing through the microwave absorption structure 15.

[0059] Compared with traditional technologies, the local oscillator adding device can add a local oscillator field to the Rydberg atomic detection system in a small space comparable to the physical size of the atomic gas chamber, and achieve the enhancement effect of the local oscillator signal and the incoming wave signal. While improving the detection sensitivity, it greatly enhances the miniaturization and engineering practicality of the Rydberg atomic detection system, achieving the purpose of having strong applicability in actual engineering applications.

[0060] In one embodiment, Figure 2 As shown, the microwave isolation module 12 includes a microwave circulator 122 and a second matching load 123. The microwave circulator 122 is used to send the local oscillator signal into the local oscillator radiation structure 13 and send the isolated reflected signal into the second matching load 123 for absorption.

[0061] It can be understood that in this embodiment, a microwave circulator 122 and a second matching load 123 are used to form the microwave isolation module 12 required above. The second matching load 123 can also be various types of matching loads already available in the art, and can be selected specifically according to the signal absorption requirements of the device. The microwave circulator 122 can be connected to the microwave signal source 11, the local oscillator radiation structure 13, and the second matching load 123 through cables or other waveguides.

[0062] Specifically, after the microwave signal source 11 generates the required local oscillator signal, it is sent to the microwave circulator 122. The microwave circulator 122 transmits the input local oscillator signal to the local oscillator radiation structure 13, and prevents the reflected signal caused by the mismatch between the local oscillator radiation structure 13 and the microwave circulator 122 from entering the microwave signal source 11. After the local oscillator signal of the microwave circulator 122 is sent to the local oscillator radiation structure 13, the local oscillator radiation structure 13 converts the local oscillator signal in the form of a guided electromagnetic wave into a spatially radiated electromagnetic wave, so that the local oscillator signal in the form of a spatially radiated electromagnetic wave can enter the resonance enhancement structure 14 through spatial coupling.

[0063] After the signal to be measured in the space enters the resonance enhancement structure 14, the resonance enhancement structure 14 also has a resonance enhancement effect on the signal to be measured at the atomic gas chamber. A part of the enhanced signal enters the local oscillator radiation structure 13 through space coupling in the form of space radiation electromagnetic waves. The local oscillator radiation structure 13 converts this part of the signal into a guided electromagnetic wave and sends it to the microwave circulator 122. The microwave circulator 122 sends this part of the signal to the second matching load 123 for absorption.

[0064] By adopting the microwave circulator 122 and the second matching load 123, the device structure can be effectively simplified, which is more conducive to the miniaturization design of the system.

[0065] In one embodiment, the first matching load 16 includes a waveguide matching load or a three-plate line matching load, and the second matching load 123 includes a waveguide matching load or a three-plate line matching load. Optionally, in this embodiment, the first matching load 16 and the second matching load 123 can adopt the same structural form, such as but not limited to the waveguide matching load or the three-plate line matching load already known in the art, to achieve a reliable incoming wave absorption effect.

[0066] In one embodiment, Figure 3 As shown, the local oscillator radiation structure 13 includes a first microwave connector 131 and a first electromagnetic wave guiding structure 132. The first microwave connector 131 receives the local oscillator signal in the microwave circulator 122 and sends it to the first electromagnetic wave guiding structure 132. The first electromagnetic wave guiding structure 132 converts the input local oscillator signal into a spatially radiated electromagnetic wave and guides it to the resonance enhancement structure 14.

[0067] It can be understood that the local oscillator radiation structure 13 in this embodiment can be composed of a microwave connector and an electromagnetic waveguide (i.e., the first electromagnetic wave guiding structure 132) in the art. The first microwave connector 131 serves as an interface for the entry and exit of the guided electromagnetic wave, and the first electromagnetic wave guiding structure 132 is responsible for converting the guided electromagnetic wave into a spatial radiation electromagnetic wave so that it can be guided to the resonance enhancement structure 14 in a spatial coupling manner, and is responsible for converting the spatial radiation electromagnetic wave coupled from the space into a guided electromagnetic wave, so that it is sent into the first microwave connector 131 and then enters the second matching load 123 through the microwave circulator 122 for absorption.

[0068] By adopting the first microwave connector 131 and the first electromagnetic wave guiding structure 132 , the device structure can be further effectively simplified, which is more conducive to the miniaturization design of the system.

[0069] In one embodiment, the first electromagnetic wave guiding structure 132 includes a rectangular waveguide, a parallel plate waveguide or a microwave antenna. Optionally, a rectangular waveguide, a parallel plate waveguide or a microwave antenna in the art can be used as the first electromagnetic wave guiding structure 132. For example, but not limited to, for electromagnetic waves below 1 GHz, a parallel plate waveguide can be used; for electromagnetic waves above 1 GHz, a rectangular waveguide can be used; in addition, a microstrip antenna or a horn antenna can also be used. By adopting the above structural form, the first electromagnetic wave guiding structure 132 can be simple and efficient, which is more conducive to the miniaturization design of the system.

[0070] In one embodiment, Figure 3 As shown, the microwave absorption structure 15 includes a second microwave joint 151 and a second electromagnetic wave guiding structure 152. The second electromagnetic wave guiding structure 152 converts the spatial radiation electromagnetic wave transmitted by the resonance enhancement structure 14 through spatial coupling into a guided electromagnetic signal and sends it to the second microwave joint 151, and the second microwave joint 151 sends the input guided electromagnetic signal to the first matching load 16 for absorption.

[0071] It can be understood that the microwave absorption structure 15 in this embodiment can adopt the same structural design as the local oscillator radiation structure 13, the second microwave joint 151 serves as an interface for the entry and exit of the guided electromagnetic waves, and the second electromagnetic wave guiding structure 152 is responsible for converting the spatial radiation electromagnetic waves coupled from the space into guided electromagnetic waves, which are sent to the second microwave joint 151 and then enter the first matching load 16 for absorption.

[0072] By adopting the second microwave connector 151 and the second electromagnetic wave guiding structure 152 , the device structure can be further effectively simplified, which is more conducive to the miniaturization design of the system.

[0073] In one embodiment, the second electromagnetic wave guiding structure 152 includes a rectangular waveguide, a parallel plate waveguide or a microwave antenna. Optionally, a rectangular waveguide, a parallel plate waveguide or a microwave antenna in the art can be used as the second electromagnetic wave guiding structure 152. For example, but not limited to, for electromagnetic waves below 1 GHz, a parallel plate waveguide can be used; for electromagnetic waves above 1 GHz, a rectangular waveguide can be used; in addition, a microstrip antenna or a horn antenna can also be used. By adopting the above structural form, the second electromagnetic wave guiding structure 152 is simple and efficient, which is more conducive to the miniaturization design of the system.

[0074] In one embodiment, the resonance enhancement structure 14 is an open resonance structure. It can be understood that in this embodiment, an open resonance structure, such as various types of open resonance switches and their structural variants, can be used as the required resonance enhancement structure 14, so that the local oscillation addition and resonance enhancement effects at the atomic gas chamber can be more reliably achieved, and the system miniaturization design requirements can be better met.

[0075] In one embodiment, Figure 4 and Figure 5 As shown, the open resonant structure includes a first pole plate 141, a second pole plate 142, a first connecting portion 143 and a second connecting portion 144. The first electromagnetic wave guiding structure 132 includes a third pole plate 132a and a fourth pole plate 132b. The second electromagnetic wave guiding structure 152 includes a fifth pole plate 152a and a sixth pole plate 152b. The first pole plate 141 and the second pole plate 142 are parallel and arranged relative to each other. The third pole plate 132a and the fourth pole plate 132b are parallel and arranged relative to each other. The fifth pole plate 152a and the sixth pole plate 152b are parallel and arranged relative to each other. The third pole plate 132a, the second pole plate 142 and the fifth pole plate 152a are collinear and structurally connected in sequence. The first connecting portion 143 structurally connects the first pole plate 141 and the third pole plate 132a, and the second connecting portion 144 structurally connects the first pole plate 141 and the fifth pole plate 152a. The fourth electrode plate 132 b and the sixth electrode plate 152 b are both located in an open resonant cavity surrounded by the first electrode plate 141 , the first connecting portion 143 , the third electrode plate 132 a , the second electrode plate 142 , the fifth electrode plate 152 a and the second connecting portion 144 .

[0076] It can be understood that in this embodiment, the local oscillator radiation structure 13, the resonance enhancement structure 14 and the microwave absorption structure 15 of the above-mentioned parallel plate structure are specifically used. The first plate 141 of the resonance enhancement structure 14 and the third plate 132a of the local oscillator radiation structure 13 are connected through the first connecting portion 143, and the second plate 142 of the resonance enhancement structure 14 and the fifth plate 152a of the microwave absorption structure 15 are connected through the second connecting portion 144, thereby forming an open resonant cavity for resonant enhancement of the signal at the atomic gas chamber. The first connecting portion 143 and the second connecting portion 144 can be made of copper, aluminum or their alloy metal materials, and can usually be processed with the first plate 141, the second plate 142, the third plate 132a and the fifth plate 152a using the same material, thereby simplifying the processing procedure and reducing the processing cost. The first connecting portion 143 and the second connecting portion 144 constitute the equivalent inductance part of the open resonant structure, and play a role in supporting and connecting the open resonant structure 14 and the entire local oscillator adding device 100.

[0077] The two parallel plates (i.e., the third plate 132a and the fourth plate 132b) of the local oscillator radiation structure 13 together constitute a parallel plate waveguide to convert the local oscillator signal input from the first microwave connector 131 through the third plate 132a into a spatially radiated electromagnetic wave and guide it to the vicinity of the resonance enhancement structure 14. In the local oscillator radiation structure 13, the size of the spatial coupling coefficient between the local oscillator radiation structure 13 and the resonance enhancement structure 14 can be changed by adjusting the length of the fourth plate 132b, thereby accurately achieving the desired spatial coupling effect.

[0078] It should be noted that if Figure 4 and Figure 5 The dotted line frame in the middle indicates the placement position of the atomic gas chamber. This embodiment is described by taking the atomic gas chamber embedded in the resonance enhancement structure 14 as an example. Figure 5 , which is a top view of one of the structural forms when the local oscillator radiation structure 13, the microwave absorption structure 15 and the resonance enhancement structure 14 are integrated into an integrated structure.

[0079] Through the above-mentioned first electrode plate 141, first connecting portion 143, third electrode plate 132a, second electrode plate 142, fifth electrode plate 152a and second connecting portion 144, a variant form of an open resonant ring can be formed together, wherein the first electrode plate 141 and the second electrode plate 142 together constitute the equivalent parallel capacitance part of the open resonant ring, and the working (resonance) frequency and its maximum resonance enhancement multiple can be changed by adjusting the impedance value of the equivalent parallel LC of the open resonant ring, so as to flexibly meet the actual engineering needs in different application scenarios. In this embodiment, the atomic gas chamber can be placed in the center of the open resonant ring formed by the first electrode plate 141 and the second electrode plate 142 (that is, the center of the equivalent parallel capacitance part of the open resonant ring) to obtain the maximum resonance enhancement effect.

[0080] In addition, the first connection portion 143 is connected to the third plate 132a structure of the local oscillator radiation structure 13, and the second connection portion 144 is connected to the fifth plate 152a structure of the microwave absorption structure 15, together forming a resonance-enhanced equivalent parallel inductance part, so that the local oscillator radiation structure 13, the microwave absorption structure 15 and the resonance enhancement structure 14 can be integrated, further enhancing the mechanical strength of the overall structure of the device and improving the degree of engineering practicality. The microwave absorption structure 15 adopts the same structural design as the local oscillator radiation structure 13, and the two are symmetrically designed with respect to the resonance enhancement structure 14 (such as spatial position and structure).

[0081] By adopting the above-mentioned design structure, the miniaturization and engineering practicality of the Rydberg atomic detection system can be further improved, so as to achieve the goal of having stronger applicability in practical engineering applications.

[0082] In one embodiment, the resonance enhancement structure 14 is used to be embedded in the atomic gas chamber or the resonance enhancement structure 14 is used to accommodate the atomic gas chamber. It can be understood that the specific combination of the resonance enhancement structure 14 and the atomic gas chamber can be specifically selected according to the relative size of the local oscillator adding device 100 and the atomic gas chamber in the actual application of the Rydberg atomic detection system, and the electromagnetic wave frequency to be detected. The specific embedding or accommodating position can be between the equivalent capacitor structures of the resonance enhancement structure 14.

[0083] In one embodiment, see Figure 6 , a Rydberg atomic detection system 200 is also provided, comprising an atomic gas chamber 201, a laser 202, a photodetector 203, a signal processing device 204 and the above-mentioned local oscillator adding device 100. The laser 202 is used to output laser to the atomic gas chamber 201. The local oscillator adding device 100 is used to add a local oscillator signal to the atomic gas chamber 201, and to resonate and enhance the local oscillator signal at the atomic gas chamber 201 and the signal to be measured. The photodetector 203 is used to detect the atomic spectrum in the atomic gas chamber 201 and convert it into an electrical signal and output it to the signal processing device 204. The signal processing device 204 is used to perform signal processing on the electrical signal to obtain detection information.

[0084] It can be understood that the specific explanation of the local oscillator adding device 100 in this embodiment can be understood by referring to the corresponding explanations in the above-mentioned embodiments of the local oscillator adding device 100, and will not be repeated here. The specific structure and function of the other components of the Rydberg atomic detection system 200 can be understood by referring to the existing similar components in the art, and will not be described in detail one by one in this specification.

[0085] Specifically, the atomic gas chamber 201 contains a certain concentration of alkali metal atoms (such as rubidium or cesium), and the laser 202 is used to generate laser light of the wavelength required to excite the alkali metal atoms to the Rydberg state, and the laser light is connected to the atomic gas chamber 201 through an optical fiber. The microwave signal source 11 of the local oscillator adding device 100 generates a local oscillator signal and can be connected to the microwave isolation module of the local oscillator adding device 100 through a coaxial cable, so as to guide the local oscillator signal to the resonance enhancement structure through the local oscillator radiation structure of the local oscillator adding device 100, thereby adding the required local oscillator signal to the signal field at the atomic gas chamber 201. The local oscillator adding device 100 is an open resonant structure that can receive electromagnetic waves (such as the signal to be measured) in free space. The signal to be measured entering the atomic gas chamber 201 will cause disturbances to the energy levels of the Rydberg atoms therein, thereby manifesting as jitters in the EIT (electromagnetic induced transparency) spectrum, which will be transmitted to the photodetector 203 through the optical fiber. The photodetector 203 can convert the jitter of the spectrum into a corresponding electrical signal. This electrical signal is transmitted via a cable to the signal processing device 204. The signal processing device 204 can process the electrical signal to obtain the required detection information.

[0086] The above-mentioned Rydberg atomic detection system 200, by applying the above-mentioned local oscillator adding device 100, can add a local oscillator field to the Rydberg atomic detection system in a small space comparable to the physical size of the atomic gas chamber 201, and achieve the enhancement effect of the local oscillator signal and the incoming wave signal. While improving the detection sensitivity, the miniaturization and engineering practicality of the Rydberg atomic detection system are greatly improved, achieving the purpose of having strong applicability in actual engineering applications.

[0087] In one embodiment, see Figure 7 , a method for designing a local oscillator adding device for a heterodyne Rydberg atomic detection system is also provided, which is applied to the local oscillator adding device 100 mentioned above, and the design method includes the following steps:

[0088] S12, determining the structural forms of the local oscillator radiation structure and the microwave absorption structure according to the frequency of the microwave to be detected.

[0089] It can be understood that according to the frequency of microwaves that the system needs to detect, it is possible to first determine which structural forms of local oscillator radiation structure and microwave absorption structure can be used in the local oscillator adding device 100. Among them, in order to better ensure the uniformity of the electric field intensity at the point where atoms in the atomic gas chamber act, the microwave absorption structure adopts the same structural form as the local oscillator radiation structure. For example, but not limited to, for electromagnetic waves below 1 GHz, a parallel plate waveguide can be used; for electromagnetic waves above 1 GHz, a rectangular waveguide can be used; in addition, microstrip antennas or horn antennas can also be used.

[0090] In the local oscillator adding device 100, the resonant frequency (i.e., the operating frequency) is mainly determined by the resonance enhancement structure, and the local oscillator radiation structure and the microwave absorption structure have little effect on the resonant frequency. However, the working bandwidth of the local oscillator radiation structure and the microwave absorption structure needs to cover the frequency of the microwaves that the system needs to detect. Therefore, the structural form of the local oscillator radiation structure and the microwave absorption structure can be first determined according to the frequency of the microwaves that the system needs to detect.

[0091] S14, determining the combination form of the resonance enhancement structure and the atomic gas chamber and the size parameters of the resonance enhancement structure according to the structure and size parameters of the atomic gas chamber.

[0092] It can be understood that, according to the specific application scenario and the requirements for the size of the atomic gas chamber, the atomic gas chamber can be embedded in the resonance enhancement structure, or the resonance enhancement structure can be embedded in the atomic gas chamber. Specifically, the specific combination form of the resonance enhancement structure and the atomic gas chamber can be specifically selected according to the structure and relative size of the local oscillator adding device 100 and the atomic gas chamber in the Rydberg atomic detection system in actual application, and the specific embedding or accommodation position can be between the equivalent capacitance structure of the resonance enhancement structure. Therefore, the combination form of the resonance enhancement structure and the atomic gas chamber can be determined based on the structure and size parameters of the atomic gas chamber in the specific application scenario, as well as the specific size parameters of the resonance enhancement structure.

[0093] S16, obtaining a maximum resonance enhancement factor when there is no local oscillator radiation structure and a microwave absorption structure according to the size parameters of the resonance enhancement structure.

[0094] It can be understood that the resonance enhancement factor when only the resonance enhancement structure is provided can be obtained through theoretical calculation, software simulation or actual processing measurement. This resonance enhancement factor is the theoretical maximum value of the resonance enhancement factor of the proposed local oscillator adding device 100 with resonance enhancement effect.

[0095] S18, determining a spatial coupling coefficient according to a maximum resonance enhancement factor and a set detection sensitivity; the spatial coupling coefficient includes a spatial coupling coefficient between the resonance enhancement structure and the local oscillator radiation structure, and a spatial coupling coefficient between the resonance enhancement structure and the microwave absorption structure.

[0096] It can be understood that the minimum resonance enhancement factor E required by the local oscillator adding device 100 can be obtained according to the detection sensitivity required by the system (ie, the set detection sensitivity). max The relationship between them satisfies:

[0097]

[0098] Among them, α represents the attenuation coefficient caused by factors such as metal and dielectric loss, which is a constant.

[0099] S20, determining the size parameters of the local oscillator radiation structure and the microwave absorption structure according to the spatial coupling coefficient, and outputting the design result data of the local oscillator adding device.

[0100] It can be understood that after obtaining the range of the spatial coupling coefficient required for system detection, the specific size parameters of the local oscillator radiation structure and the microwave absorption structure can be determined so that the spatial coupling coefficient satisfies the range given in the above formula (1). At this point, the basic design of the local oscillator adding device 100 can be completed. For the microwave signal source, the microwave isolation module and the first matching load, it is only necessary to add options according to the needs of the device.

[0101] The above-mentioned design method first determines the structural form of the local oscillator radiation structure and the microwave absorption structure according to the frequency of the microwave to be detected, and then determines the combination form of the resonance enhancement structure and the atomic gas chamber, as well as the size of the resonance enhancement structure according to the structure and size of the atomic gas chamber. Then, the maximum resonance enhancement factor of the device is determined according to the determined size of the resonance enhancement structure. Then, according to the maximum resonance enhancement factor and the detection sensitivity required by the system, the spatial coupling coefficient between the resonance enhancement structure and the local oscillator radiation structure and the microwave absorption structure is determined. Finally, the specific sizes of the local oscillator radiation structure and the microwave absorption structure can be determined according to the determined spatial coupling coefficient, thereby outputting the final design result data. According to the design result data, the required local oscillator adding device 100 can be efficiently manufactured to achieve the purpose of having strong applicability in practical engineering applications.

[0102] In some implementations, in order to make it easier to intuitively understand the above technical solutions provided by the present application, some simulation examples of applying the above solutions are provided below. Figure 8 The figure is a schematic diagram of the simulation results of the resonance enhancement factor of the local oscillator adding device 100 applied to the heterodyne Rydberg atomic detection system when there is no local oscillator signal. Curve 501 is a curve showing the change of the resonance enhancement factor of the incoming wave signal with the detected microwave frequency. The marked point 502 indicates the point where the resonance enhancement factor of the incoming wave signal is the largest. At 689MHz, there is a maximum resonance factor E max It is 162.30827 times.

[0103] like Fig. 9 , which is a schematic diagram of the simulation results of the reflection coefficient of the local oscillator signal in one of the simulation examples of the local oscillator adding device 100 applied to the heterodyne Rydberg atomic detection system. Curve 601 is a curve showing the change of the reflection coefficient of the local oscillator signal with the frequency of the local oscillator signal, and the mark point 602 represents the reflection coefficient at the maximum resonance enhancement multiple frequency, that is, the reflection coefficient Γ at 689MHz is 0.85959, from which the spatial coupling coefficient η of this specific embodiment is obtained to be 1-Γ=0.14041.

[0104] like Fig.10 As shown, it is a simulation result diagram of the resonance enhancement factor when adding a local oscillator signal to a specific embodiment of a local oscillator adding device applied to a heterodyne Rydberg atomic detection system. Curve 701 is a curve showing the change of the resonance enhancement factor of the incoming wave signal with the detected microwave frequency when there is a local oscillator signal, and the mark point 702 indicates the resonance enhancement factor E of the incoming wave signal at 689MHz when there is a local oscillator signal. LO It is 129.69381 times.

[0105] Analyzing the above simulation data, we can obtain the spatial coupling coefficient η and the maximum resonance multiple E when there is no local oscillation signal. max and the maximum resonance multiple E when there is a local oscillator signal LO The relationship between: Among them, α represents the attenuation coefficient caused by factors such as metal and dielectric loss, which is a constant. Substituting the above data into the attenuation coefficient α in this example, we can get 1.0757.

[0106] It should be understood that although Figure 7 The steps in the flowchart are shown in sequence as indicated by the arrows, but the steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of the steps, and the steps can be executed in other orders. Figure 7 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequentially, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0107] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and all of them belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A local oscillator adding device for heterodyne Rydberg atomic detection system, characterized in that: It includes a microwave signal source, a microwave isolation module, a local oscillator radiation structure, a resonance enhancement structure, a microwave absorption structure and a first matching load; the microwave signal source is used to generate a local oscillator signal and send it to the microwave isolation module, and the microwave isolation module is used to send the local oscillator signal to the local oscillator radiation structure and isolate the reflected signal of the local oscillator radiation structure; The local oscillator radiation structure is used to transmit the local oscillator signal to the resonance enhancement structure through spatial coupling, the resonance enhancement structure is used to resonate and enhance the local oscillator signal at the atomic gas chamber and the signal to be measured, and the first matching load is used to absorb the guided electromagnetic signal; wherein the local oscillator radiation structure includes a first electromagnetic wave guiding structure, the first electromagnetic wave guiding structure converts the input local oscillator signal into a spatial radiation electromagnetic wave and guides it to the resonance enhancement structure, and the microwave absorption structure includes a second electromagnetic wave guiding structure, the second electromagnetic wave guiding structure converts the spatial radiation electromagnetic wave transmitted from the resonance enhancement structure through spatial coupling into the guided electromagnetic signal; The resonance enhancement structure is an open resonance structure, the open resonance structure includes a first pole plate, a second pole plate, a first connecting portion and a second connecting portion, the first electromagnetic wave guiding structure includes a third pole plate and a fourth pole plate, and the second electromagnetic wave guiding structure includes a fifth pole plate and a sixth pole plate; The first electrode plate and the second electrode plate are parallel and arranged relative to each other, the third electrode plate and the fourth electrode plate are parallel and arranged relative to each other, the fifth electrode plate and the sixth electrode plate are parallel and arranged relative to each other, the third electrode plate, the second electrode plate and the fifth electrode plate are collinear and structurally connected in sequence, the first connecting portion structurally connects the first electrode plate and the third electrode plate, and the second connecting portion structurally connects the first electrode plate and the fifth electrode plate; The fourth electrode plate and the sixth electrode plate are both located in an open resonant cavity surrounded by the first electrode plate, the first connecting portion, the third electrode plate, the second electrode plate, the fifth electrode plate and the second connecting portion.

2. The local oscillator adding device for heterodyne Rydberg atomic detection system according to claim 1, characterized in that: The microwave isolation module includes a microwave circulator and a second matching load; The microwave circulator is used to send the local oscillator signal into the local oscillator radiation structure and send the isolated reflected signal into the second matching load for absorption.

3. The local oscillator adding device for heterodyne Rydberg atomic detection system according to claim 2, characterized in that: The local oscillator radiation structure also includes a first microwave connector; The first microwave connector is connected to the local oscillator signal in the microwave circulator and sent to the first electromagnetic wave guiding structure.

4. The local oscillator adding device for heterodyne Rydberg atomic detection system according to claim 3, characterized in that: The first electromagnetic wave guiding structure includes a rectangular waveguide, a parallel plate waveguide or a microwave antenna.

5. The local oscillator adding device for heterodyne Rydberg atomic detection system according to claim 3 or 4, characterized in that: The microwave absorbing structure further comprises a second microwave joint; The second electromagnetic wave guiding structure sends the guided electromagnetic signal to the second microwave connector, and the second microwave connector sends the input guided electromagnetic signal to the first matching load for absorption.

6. The local oscillator adding device for heterodyne Rydberg atomic detection system according to claim 5, characterized in that: The second electromagnetic wave guiding structure includes a rectangular waveguide, a parallel plate waveguide or a microwave antenna.

7. The local oscillator adding device for heterodyne Rydberg atomic detection system according to claim 1, characterized in that: The resonance enhancement structure is used to be embedded in the atomic gas chamber or the resonance enhancement structure is used to accommodate the atomic gas chamber.

8. The local oscillator adding device for heterodyne Rydberg atomic detection system according to claim 2, characterized in that: The first matching load includes a waveguide matching load or a three-plate line matching load, and the second matching load includes a waveguide matching load or a three-plate line matching load.

9. A Rydberg atomic detection system, characterized in that: It comprises an atomic gas chamber, a laser, a photodetector, a signal processing device and a local oscillator adding device as claimed in any one of claims 1 to 8; The laser is used to output laser light to the atomic gas chamber, and the local oscillator adding device is used to add a local oscillator signal to the atomic gas chamber, and to resonate and enhance the local oscillator signal at the atomic gas chamber and the signal to be measured; The photoelectric detector is used to detect the atomic spectrum in the atomic gas chamber and convert it into an electrical signal and output it to the signal processing device. The signal processing device is used to perform signal processing on the electrical signal to obtain detection information.

10. A method for designing a local oscillator adding device for a heterodyne Rydberg atomic detection system, applied to the local oscillator adding device according to any one of claims 1 to 8, characterized in that: The design method comprises: Determine the structural forms of the local oscillator radiation structure and the microwave absorption structure according to the frequency of the microwave to be detected; According to the structure and size parameters of the atomic gas chamber, the combination form of the resonance enhancement structure and the atomic gas chamber and the size parameters of the resonance enhancement structure are determined; According to the size parameters of the resonance enhancement structure, obtaining the maximum resonance enhancement factor when the local oscillator radiation structure and the microwave absorption structure are not present; Determining a spatial coupling coefficient according to the maximum resonance enhancement factor and the set detection sensitivity; the spatial coupling coefficient includes a spatial coupling coefficient between the resonance enhancement structure and the local oscillator radiation structure, and a spatial coupling coefficient between the resonance enhancement structure and the microwave absorption structure; According to the spatial coupling coefficient, the size parameters of the local oscillator radiation structure and the microwave absorption structure are determined, and the design result data of the local oscillator adding device are output.

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