Broadband Rydberg atom microwave detection system

Abstract

The invention relates to a broadband Rydberg atom microwave detection system, and the system comprises a microwave transmitting module which is used for transmitting a mixed microwave signal composed of an intrinsic microwave signal and a to-be-detected microwave signal; the microwave slab waveguide is used for widening the working frequency band and amplifying the mixed microwave signal; the optical standing wave cavity module is arranged on the microwave slab waveguide and used for enabling the detection light and the coupling light to enter an optical standing wave cavity, enabling the coupling light to be thinned and restraining the coupling light to reciprocate in the optical standing wave cavity so as to broaden the instantaneous bandwidth; the atomic gas chamber is arranged on the microwave slab waveguide and located in the optical standing wave cavity module, and rubidium atoms are arranged in the atomic gas chamber; and the detection module is arranged corresponding to the atomic gas chamber and is used for receiving and analyzing the detection light emitted from the atomic gas chamber so as to realize microwave detection. Through the optical standing wave cavity and the microwave slab waveguide, the instantaneous bandwidth of the single intrinsic microwave is widened, the working frequency band is widened, the bandwidth problem can be solved, and high-sensitivity microwave detection can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of microwave quantum detection, in particular to a wide bandwidth Rydberg atom microwave detection system. BACKGROUND

[0002] Rydberg atom refers to a highly excited state atom with a principal quantum number n much larger than 1. Rydberg atom has a very large polarizability and a microwave transition electric dipole moment, so the response of Rydberg atom to external electric field is extremely sensitive; with the change of the principal quantum number of Rydberg atom, it has very rich microwave energy level transition, and the transition frequency can cover a super wide range from MHz to THz. Compared with ground state atoms and low excited state atoms, Rydberg atom has a longer radiation lifetime, which can obtain a longer coherent measurement integration time, which is beneficial to obtain higher coherent measurement sensitivity, so Rydberg atom antenna is very suitable for microwave detection.

[0003] In the existing Rydberg atom microwave detection scheme, superheterodyne detection is used, that is, an eigenmicrowave is used to improve the detection sensitivity of the system; however, due to the limitation of the response speed of the atom, the instantaneous bandwidth of the superheterodyne detection based on a single eigenmicrowave is usually only a few hundred kHz, which greatly limits the practicality range. Some schemes also propose a large instantaneous bandwidth scheme, but the sensitivity is affected to some extent. SUMMARY

[0004] The present application provides a wide bandwidth Rydberg atom microwave detection system to solve at least one of the above technical problems.

[0005] The technical scheme for solving the above technical problems is as follows: a wide bandwidth Rydberg atom microwave detection system, comprising: a microwave emission module for emitting a mixed microwave signal composed of an eigenmicrowave signal and a to-be-detected microwave signal; a microwave slab waveguide corresponding to the microwave emission module, for widening the working frequency band and amplifying the mixed microwave signal; an optical standing wave cavity module arranged on the microwave slab waveguide, for allowing detection light and coupling light to enter the optical standing wave cavity, and for thinning the coupling light and constraining the coupling light to reciprocate in the optical standing wave cavity to widen the instantaneous bandwidth; an atomic cell arranged on the microwave slab waveguide and located in the optical standing wave cavity module, and having rubidium atoms therein; the detection light and the coupling light entering the optical standing wave cavity module from opposite directions enter the atomic cell, the mixed microwave signal amplified by the microwave slab waveguide enters the atomic cell by radiation, and the frequencies of the detection light, the coupling light and the mixed microwave signal match the energy level difference of the rubidium atoms; The detection module is arranged correspondingly to the atomic gas chamber, and is configured to receive and analyze the detection light emitted from the atomic gas chamber to realize microwave detection.

[0006] Based on the above technical solution, the application can be further improved as follows.

[0007] Further, the frequency difference between the intrinsic microwave signal and the to-be-detected microwave signal ranges from 10 kHz to 200 kHz.

[0008] Further, the optical standing wave cavity module comprises: a plano-concave mirror configured to transmit the detection light; a plane mirror arranged oppositely to the plano-concave mirror and combined with the plano-concave mirror to form the optical standing wave cavity; a converging lens arranged correspondingly to the plane mirror and configured to transmit and focus the coupling light, so that the focal point of the coupling light is on the plano-concave mirror, and the focused coupling light is transmitted into the optical standing wave cavity through the plane mirror and reciprocates in the optical standing wave cavity.

[0009] Further, the reflectivity of the plano-concave mirror ranges from 95% to 97%.

[0010] Further, the reflectivity of the plane mirror is not less than 99%.

[0011] Further, the atomic gas chamber is arranged at the center of the plano-concave mirror and the plane mirror.

[0012] Further, the energy levels of the rubidium atoms include a ground state energy level, an excited state energy level, a first Rydberg energy level and a second Rydberg energy level; wherein the energy level difference between the ground state energy level and the excited state energy level is defined as a first energy level difference, the energy level difference between the excited state energy level and the first Rydberg energy level is defined as a second energy level difference, and the energy level difference between the first Rydberg energy level and the second Rydberg energy level is defined as a third energy level difference. The laser frequency of the detection light matches the first energy level difference, the center frequency of the coupling light matches the second energy level difference, and the frequency of the intrinsic microwave signal and the frequency of the to-be-detected microwave signal both match the third energy level difference.

[0013] Further, the second Rydberg energy level is located between the first Rydberg energy level and the excited state energy level.

[0014] Further, the microwave emission module comprises: an intrinsic microwave signal source configured to generate the intrinsic microwave signal; a to-be-detected microwave signal source configured to generate the to-be-detected microwave signal; A microwave power mixer is connected to the intrinsic microwave signal source and the microwave signal source under test, and is used to mix the intrinsic microwave signal and the microwave signal under test to obtain the mixed microwave signal.

[0015] Furthermore, it also includes a dichroic mirror, which is disposed between the optical standing wave cavity module and the detection module; the dichroic mirror is used to reflect the coupled light transmitted from the converging lens to the plano-concave mirror, and to transmit the detection light emitted from the atomic gas cell to the detection module.

[0016] The beneficial effects of this invention are as follows: In the wideband Rydberg atomic microwave detection system of this invention, the microwave planar waveguide has a wide operating frequency band, which can meet the requirements of wideband detection; at the same time, the optical standing wave cavity module can make the coupling light very thin and make it travel back and forth in the optical standing wave cavity multiple times, which can achieve wideband high-sensitivity detection; this invention, through the optical standing wave cavity and the microwave planar waveguide, broadens the instantaneous bandwidth of single intrinsic microwave and broadens the operating frequency band, which can solve the bandwidth problem and achieve high-sensitivity microwave detection, and has potential application value in electronic detection, electronic countermeasures, radar imaging and other fields. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a wideband Rydberg atomic microwave detection system according to the present invention; Figure 2 This is a schematic diagram of the energy levels of a rubidium atom.

[0018] The attached diagram lists the components represented by each number as follows: 1. Microwave transmitting module; 11. Intrinsic microwave signal source; 12. Microwave signal source under test; 13. Microwave power mixer; 2. Microwave planar waveguide; 3. Optical standing wave cavity module; 31. Planar-concave mirror; 32. Planar mirror; 33. Converging lens; 4. Atomic gas cell; 5. Detection module; 6. Dichroic mirror; A. Ground state energy level; B. Excited state energy level; C. Rydberg first energy level; D. Rydberg second energy level. Detailed Implementation

[0019] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0020] like Figure 1 As shown, a wideband Rydberg atomic microwave detection system includes: Microwave transmitting module 1 is used to transmit a mixed microwave signal consisting of intrinsic microwave signal and microwave signal under test; The microwave planar waveguide 2 is configured corresponding to the microwave transmitting module 1, and is used to broaden the operating frequency band and amplify the hybrid microwave signal; An optical standing wave cavity module 3 is disposed on the microwave flat waveguide 2 to allow the probe light and the coupling light to enter the optical standing wave cavity, and to make the coupling light thinner and constrain the coupling light to reciprocate within the optical standing wave cavity, thereby widening the instantaneous bandwidth. An atomic gas chamber 4 is disposed on the microwave flat waveguide 2 and located in the optical standing wave cavity module 3, and contains rubidium atoms. The probe light and the coupling light entering the optical standing wave cavity module 3 enter the atomic gas chamber 4 from opposite directions. The mixed microwave signal, amplified by the microwave flat waveguide 2, enters the atomic gas chamber 4 through radiation, and the frequencies of the probe light, the coupling light, and the mixed microwave signal match the energy level difference of the rubidium atoms. The detection module 5 is configured corresponding to the atomic gas chamber 4 and is used to receive and analyze the detection light emitted from the atomic gas chamber 4 to achieve microwave detection.

[0021] In this invention's wideband Rydberg atom microwave detection system, the microwave planar waveguide has a wide operating frequency band, enabling wideband detection. Simultaneously, the optical standing wave cavity module allows the coupling light to become very thin and travel back and forth multiple times within the optical standing wave cavity, achieving wideband, high-sensitivity detection. This invention, through the optical standing wave cavity and microwave planar waveguide, broadens the instantaneous bandwidth of a single intrinsic microwave and simultaneously expands the operating frequency band, solving both bandwidth limitations and achieving high-sensitivity microwave detection. It has potential application value in electronic detection, electronic countermeasures, and radar imaging.

[0022] In some embodiments, such as Figure 1 As shown: The microwave transmitting module 1 includes: Intrinsic microwave signal source 11 is used to generate the intrinsic microwave signal; Microwave signal source 12 is used to generate the microwave signal to be tested; The microwave power mixer 13 is connected to the intrinsic microwave signal source 11 and the microwave signal source under test 12, and is used to mix the intrinsic microwave signal and the microwave signal under test to obtain the mixed microwave signal.

[0023] Preferably, the frequency difference between the intrinsic microwave signal and the microwave signal under test is in the range of 10kHz to 200kHz.

[0024] Specifically, the eigen microwave signal and the to-be-detected microwave signal are generated by an eigen microwave signal source 11 and a to-be-detected microwave signal source 12, and enter a microwave slab waveguide 2 through a microwave power mixer 13. The microwave slab waveguide 2 has a microwave convergence effect and can amplify the eigen microwave signal and the to-be-detected microwave signal. The entire optical standing wave cavity and the atomic cell 4 are placed on the microwave slab waveguide 2, and the mixed microwave signal amplified by the microwave slab waveguide 2 can enter the atomic cell 4 through radiation.

[0025] The working frequency band of the microwave slab waveguide 2 for widening the working frequency band refers to the frequency of the to-be-detected microwave signal f 0which can cover a very wide frequency range. Taking a typical microwave slab waveguide 2 as an example, the principle of widening the working frequency band is as follows: the microwave slab waveguide 2 supports microwave transmission of 2-20 GHz, and forms evanescent waves of microwaves near the atomic cell 4 above the microwave slab waveguide 2, which coincide with the probe light, so that the rubidium atoms in the atomic cell 4 can simultaneously sense the light and the microwaves; during the detection process, the frequency of the eigen microwave signal f is changed to keep the frequency difference between the eigen microwave signal and the to-be-detected microwave signal f at any frequency point (specifically, 0.1 MHz) between 10 kHz and 200 kHz, so that microwave detection signals of different frequency bands can be obtained.

[0026] In some embodiments, as shown in Figure 1 : The optical standing wave cavity module 3 comprises: a plano-concave mirror 31 configured to transmit the probe light; a plane mirror 32 disposed opposite to the plano-concave mirror 31 and combined with the plano-concave mirror 31 to form the optical standing wave cavity; a converging lens 33 disposed corresponding to the plane mirror 32 and configured to transmit and focus the coupling light so that the focal point of the coupling light is on the plano-concave mirror 31, and the focused coupling light is injected into the optical standing wave cavity through the plane mirror 32 and reciprocates in the optical standing wave cavity.

[0027] Specifically, the plano-concave mirror 31 and the plane mirror 32 are combined to form an optical standing wave cavity, which functions to confine the coupling light so that the coupling light can reciprocate in the optical standing wave cavity and form an optical standing wave, as shown by the back-and-forth reciprocating thick arrows in Figure 1 . The principle of widening the instantaneous bandwidth of the present application is that the widening of the instantaneous bandwidth is mainly realized by the optical standing wave cavity. After the coupling light passes through the optical standing wave cavity, the light beam becomes very thin and reciprocates in the optical standing wave cavity multiple times to complete the wideband high-sensitivity detection.

[0028] Preferably, in order to ensure that the coupled light reciprocates within the optical standing wave cavity, there are requirements for the reflectivity of the plano-concave mirror 31 and the reflectivity of the plane mirror 32; wherein, the reflectivity of the plano-concave mirror 31 is in the range of 95%~97%, and the reflectivity of the plane mirror 32 is not less than 99%.

[0029] Preferably, the atomic gas chamber 4 is located at the center of the plano-concave reflector 31 and the planar reflector 32, that is, the distance from the atomic gas chamber 4 to the plano-concave reflector 31 is equal to the distance to the planar reflector 32, so as to satisfy the beam matching condition.

[0030] In some embodiments, such as Figure 2 As shown: The energy levels of the rubidium atom include a ground state energy level A, an excited state energy level B, a Rydberg first energy level C, and a Rydberg second energy level D, wherein the Rydberg second energy level D is located between the Rydberg first energy level C and the excited state energy level B; wherein the energy level difference between the ground state energy level A and the excited state energy level B is defined as the first energy level difference, the energy level difference between the excited state energy level B and the Rydberg first energy level C is defined as the second energy level difference, and the energy level difference between the Rydberg first energy level C and the Rydberg second energy level D is defined as the third energy level difference; The laser frequency of the probe light f 1. Matching the first energy level difference, the center frequency of the coupled light f 2. Matching the second energy level difference, the frequency of the intrinsic microwave signal f and the frequency of the microwave signal to be measured f 0 all match the third energy level difference.

[0031] Specifically, the probe light enters the atomic gas cell 4 via the plano-concave reflector 31, and its laser frequency matches the energy level difference between AB; the coupling light enters the atomic gas cell 4 via the optical standing wave cavity module 3, in the opposite direction to the probe light, and its center frequency matches the energy level difference between BC; the intrinsic microwave signal is a microwave of a specific frequency, its frequency... f Matching the energy level difference with the CD; the frequency of the microwave signal under test. f 0 and the frequency of this microwave signal f The phase difference is 0.1MHz (i.e.) f 0 =f+ (0.1MHz), there are no specific requirements for the phase of the microwave signal under test, frequency f The energy level difference between 0 and CD must be matched; only by achieving the above-mentioned energy level difference matching can the atom be excited.

[0032] In some embodiments, such as Figure 1 As shown: The application also comprises a dichroic mirror 6, which is arranged between the optical standing wave cavity module 3 and the detection module 5; the dichroic mirror 6 is used for reflecting the coupling light transmitted from the converging lens 33 to the flat-concave mirror 31, and transmitting the detection light emitted from the atomic cell 4 to the detection module 5.

[0033] The function of the dichroic mirror 6 is to realize the reflection of the coupling light and the transmission of the detection light. The intrinsic microwave signal and the signal field to be measured are loaded into the atomic cell 4 after being amplified by the microwave slab waveguide 2, finally, the detection light carrying the microwave information enters the detection module 5, which can be a detector and a spectrum analyzer, and the corresponding detection data can be obtained through the detector and the spectrum analyzer.

[0034] In summary, the application introduces a standing wave optical cavity to realize the improvement of the instantaneous bandwidth, introduces a microwave slab waveguide to realize wide-frequency detection, and further realizes wide-frequency wide-band measurement; therefore, the application can solve the bandwidth and realize high-sensitivity microwave detection.

[0035] The above only describes the preferred embodiments of the application and is not used to limit the application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A wideband Rydberg atomic microwave detection system, characterized in that, include: Microwave transmitting module (1), which is used to transmit a mixed microwave signal consisting of intrinsic microwave signal and microwave signal under test; A microwave planar waveguide (2) is provided corresponding to the microwave transmitting module (1) to broaden the operating frequency band and amplify the hybrid microwave signal; An optical standing wave cavity module (3) is disposed on the microwave flat waveguide (2) to allow the probe light and the coupling light to enter the optical standing wave cavity, and to make the coupling light thinner and constrain the coupling light to reciprocate within the optical standing wave cavity, so as to broaden the instantaneous bandwidth. An atomic gas chamber (4) is disposed on the microwave flat waveguide (2) and located in the optical standing wave cavity module (3), and contains rubidium atoms; the probe light and the coupling light that enter the optical standing wave cavity module (3) enter the atomic gas chamber (4) from opposite directions; the mixed microwave signal amplified by the microwave flat waveguide (2) enters the atomic gas chamber (4) through radiation, and the frequencies of the probe light, the coupling light and the mixed microwave signal match the energy level difference of the rubidium atoms; The detection module (5) is configured corresponding to the atomic gas chamber (4) and is used to receive and analyze the detection light emitted from the atomic gas chamber (4) to realize microwave detection.

2. The wideband Rydberg atomic microwave detection system according to claim 1, characterized in that, The frequency difference between the intrinsic microwave signal and the microwave signal under test is in the range of 10kHz to 200kHz.

3. The wideband Rydberg atomic microwave detection system according to claim 1, characterized in that, The optical standing wave cavity module (3) includes: Plano-concave reflector (31) is used to transmit the probe light; A planar reflector (32) is disposed relative to the plano-concave reflector (31) and is combined with the plano-concave reflector (31) to form the optical standing wave cavity; A converging lens (33) is provided corresponding to the plane mirror (32) for transmitting the coupled light and focusing the coupled light so that the focal point of the coupled light is on the plane mirror (31). The focused coupled light enters the optical standing wave cavity through the plane mirror (32) and reciprocates within the optical standing wave cavity.

4. The wideband Rydberg atomic microwave detection system according to claim 3, characterized in that, The reflectivity of the plano-concave mirror (31) ranges from 95% to 97%.

5. The wideband Rydberg atomic microwave detection system according to claim 3, characterized in that, The reflectivity of the plane mirror (32) is not less than 99%.

6. The wideband Rydberg atomic microwave detection system according to claim 3, characterized in that, The atomic gas chamber (4) is located at the center of the plano-concave reflector (31) and the planar reflector (32).

7. The wideband Rydberg atomic microwave detection system according to claim 1, characterized in that, The energy levels of the rubidium atom include a ground state energy level, an excited state energy level, a Rydberg first energy level, and a Rydberg second energy level; wherein, the energy level difference between the ground state energy level and the excited state energy level is defined as the first energy level difference, the energy level difference between the excited state energy level and the Rydberg first energy level is defined as the second energy level difference, and the energy level difference between the Rydberg first energy level and the Rydberg second energy level is defined as the third energy level difference; The laser frequency of the probe light matches the first energy level difference, the center frequency of the coupling light matches the second energy level difference, and the frequencies of the intrinsic microwave signal and the microwave signal under test both match the third energy level difference.

8. The wideband Rydberg atomic microwave detection system according to claim 7, characterized in that, The second Rydberg level is located between the first Rydberg level and the excited state level.

9. The wideband Rydberg atomic microwave detection system according to claim 1, characterized in that, The microwave transmitting module (1) includes: Intrinsic microwave signal source (11) is used to generate the intrinsic microwave signal; The microwave signal source (12) is used to generate the microwave signal to be tested; A microwave power mixer (13) is connected to the intrinsic microwave signal source (11) and the microwave signal source under test (12) to mix the intrinsic microwave signal and the microwave signal under test to obtain the mixed microwave signal.

10. The wideband Rydberg atomic microwave detection system according to claim 3, characterized in that, It also includes a dichroic mirror (6), which is disposed between the optical standing wave cavity module (3) and the detection module (5); the dichroic mirror (6) is used to reflect the coupled light transmitted from the converging lens (33) to the plano-concave mirror (31), and to transmit the detection light emitted from the atomic gas chamber (4) to the detection module (5).

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