阅读说明：本技术 一种基于里德堡原子的微波激光双向相干转换装置 (Microwave laser bidirectional coherent conversion device based on rydberg atoms ) 是由 马菁汀 孙悦 唐倩 于 2019-11-19 设计创作，主要内容包括：本发明公开了一种基于里德堡原子的微波激光双向相干转换装置,包括原子气室(1)、第一激光器(2)、第二激光器(3)、第一微波源(8)。所述原子气室(1)为装有碱金属原子蒸汽的玻璃泡。对所述的原子气室(1)内的里德堡原子的调控,形成6能级系统,从而实现对入射原子气室(1)的转换微波和转换激光的耦合,形成量子态微波和量子态激光之间的耦合接口。本发明可以实现微波和激光之间的宽带高效双向相干转换,且不需要谐振腔、微纳器件或超低温制冷,具有装置简洁、易于集成的优点,适于在雷达、通信等领域广泛推广。(The invention discloses a microwave laser bidirectional coherent conversion device based on rydberg atoms, which comprises an atom gas chamber (1), a first laser (2), a second laser (3) and a first microwave source (8). The atomic gas chamber (1) is a glass bubble filled with alkali metal atomic vapor. And regulating and controlling the rydberg atoms in the atomic gas chamber (1) to form a 6-level system, thereby realizing the coupling of the converted microwaves and the converted laser incident to the atomic gas chamber (1) and forming a coupling interface between the quantum state microwaves and the quantum state laser. The invention can realize the broadband high-efficiency bidirectional coherent conversion between the microwave and the laser, does not need a resonant cavity, a micro-nano device or ultralow temperature refrigeration, has the advantages of simple device and easy integration, and is suitable for being widely popularized in the fields of radar, communication and the like.)

1. A microwave laser bidirectional coherent conversion device based on a rydberg atom is characterized in that: comprises an atomic gas chamber (1), a first laser (2), a second laser (3) and a first microwave source (8);

the atomic gas chamber (1) is a glass bubble filled with alkali metal atomic vapor;

the detection laser output by the first laser (2), the coupling laser output by the second laser (3) and the coupling microwave output by the first microwave source (8) are injected into the atomic gas chamber (1);

the density of alkali metal atom steam in the atom gas chamber (1), the frequency output by the first microwave source (8), the frequency of the probe light and the coupling light output by the first laser (2) and the second laser (3) are adjusted, the rydberg atoms in the atom gas chamber (1) are regulated and controlled, a 6-level system is formed, and therefore the coupling of the conversion microwaves and the conversion laser incident to the atom gas chamber (1) is realized.

2. A microwave laser bi-directional coherent conversion device based on rydberg atoms, as claimed in claim 1, wherein: regulating and controlling the energy level of the rydberg atoms in the atom gas chamber (1) to form a 6-level system, which is specifically as follows:

energy level |3>, energy level |4>, energy level |5> are the Reidberg energy levels, the transition laser is coupled to energy level |3> and energy level |4>, the coupling microwave is coupled to energy level |4> and energy level |5>, the probing laser and the coupling laser generate coherence during energy level transitions of energy level |1>, energy level |2> and energy level |3>, the coupling laser and the coupling microwave link microwave transitions and laser transition processes, and the transition laser is coupled to energy level |1> and energy level |6 >.

3. A microwave laser bi-directional coherent conversion device based on rydberg atoms, as claimed in claim 2, wherein:

the frequency of the detection laser output by the first laser (2) is locked on the resonance transition line of the energy level |1> and the energy level |2 >; the frequency of the coupled laser output by the second laser (3) is locked on the resonance transition line of the energy level |2> and the energy level |3 >; the ratio frequency omega R of the coupling laser coupling energy level |2> and energy level |3> output by the second laser (3) and the ratio frequency omega P of the detection laser coupling energy level |1> and energy level |2> output by the first laser (2) satisfy the relation: | Ω R | > > | Ω P |; the detuning quantity delta 4 caused by the change of the energy level |4> in the atomic gas chamber (1), the detuning quantity delta 5 caused by the change of the energy level |5> in the atomic gas chamber 1, and the ratio frequency omega C of the coupling microwave coupling energy level |4> and the energy level |5> output by the first microwave source (8) satisfy the relation delta 5 ═ omega C | 2/delta 4; the detuning quantity delta 5 caused by the change of the energy level |5> in the atomic gas cell (1), the detuning quantity delta 6 caused by the change of the energy level |6> in the atomic gas cell (1), and the draw ratio frequency omega A of the coupling laser coupling energy level |5> and the energy level |6> output by the second laser (3) satisfy the relation delta 6 ═ omega A | 2/delta 5; the bandwidth of the converted microwave is far smaller than the detuning quantities delta 4, delta 5 and delta 6 caused by the changes of the energy levels |4>, |5>, |6 >.

4. A microwave laser bi-directional coherent conversion device based on rydberg atoms, according to claim 3, characterized in that: the frequency range of the converted microwaves is 300MHz-300 GHz; the frequency range of the auxiliary microwave output by the first microwave source (8) is 300MHz-300GHz, and has a certain frequency difference with the frequency of the converted microwave.

5. A microwave laser bi-directional coherent conversion device based on rydberg atoms, as claimed in claim 1, wherein: the atomic gas cell comprises a first dichroic mirror (4), a first lens group (6), a second dichroic mirror (5) and a second lens group (7), wherein detection laser is output by a first laser (2), is transmitted by the first dichroic mirror (4), is shaped by the first lens group (6), and is incident into one end of an atomic gas cell (1); the second laser (3) outputs coupled laser, is shaped by the second lens group (7) after being transmitted by the second dichroic mirror (5), and is incident into the other end of the atomic gas chamber (1).

6. A microwave laser bidirectional coherent conversion device based on the rydberg atoms, according to claim 5, characterized in that: and the end face of the first dichroic mirror (4) forms a 45-degree included angle with the transmission direction of the detection laser and is used for separating the coupling laser from the detection laser.

7. A microwave laser bidirectional coherent conversion device based on the rydberg atoms, according to claim 5, characterized in that: the light conversion laser light source device is characterized by further comprising a light conversion laser separator (10), wherein conversion laser light is incident to the end face of the second dichroic mirror (5) through the light conversion laser separator (10), is shaped by the second lens group (7) after being reflected, and is incident into the atom air chamber (1).

8. The microwave laser bidirectional coherent conversion device based on the rydberg atoms, according to claim 7, characterized in that: an included angle of 45 degrees is formed between the end face of the second dichroic mirror (5) and the transmission direction of the coupling laser, the included angle is used for reflecting the conversion laser formed by the detection laser and the atom air chamber (1) to the conversion laser separator (10), and the conversion laser separator (10) filters the detection laser and outputs the conversion laser.

Technical Field

The invention relates to the field of quantum radars, in particular to a microwave laser bidirectional coherent conversion device based on a rydberg atom.

Background

The quantum radar related by the invention is a detection system which uses microwave or laser carrying quantum state information to irradiate a target and uses the quantum information carried by the interaction of the quantum state microwave or laser and the target to obtain target information. The system uses a quantum light source or a quantum microwave source to emit quantum state laser or microwave, and irradiates a target through a modulation emission system with a function of maintaining quantum information; a receiving detection system with a function of keeping quantum information detects a quantum state echo signal reflected by a target; by analyzing the echo signal, target information can be derived. The microwave quantum radar has the advantages of strong penetrability and all-weather working, but the quantum microwave source and the quantum microwave detector are difficult to prepare and need to work in an ultralow temperature environment, so that the system is large and complex; the laser quantum radar has the advantages of mature quantum light source and quantum detector technology and high working reliability, but has the defects of poor penetrability and incapability of effectively working in severe environment; the above factors limit the system implementation and engineering applications of quantum radars. In order to fully exert the advantages of the microwave quantum radar and the laser quantum radar, a microwave laser bidirectional coherent conversion device needs to be developed, technical guarantee is provided for realizing the quantum radar which has high sensitivity and can work all day long, and the research of related technologies is not available at present.

Disclosure of Invention

The invention aims to provide a microwave laser bidirectional coherent conversion device.

In order to solve the technical problem, the invention provides a microwave laser bidirectional coherent conversion device based on a rydberg atom, which adopts the following technical scheme:

the microwave laser bidirectional coherent conversion device based on the rydberg atoms comprises an atom gas chamber, a first laser, a second laser and a first microwave source;

the atomic gas chamber is a glass bubble filled with alkali metal atomic vapor;

the detection laser output by the first laser, the coupling laser output by the second laser and the coupling microwave output by the first microwave source are injected into the atomic gas chamber;

the density of alkali metal atom steam in the atom gas chamber, the frequency output by the first microwave source, the probe light output by the first laser and the second laser and the frequency of the coupling light are adjusted, the rydberg atoms in the atom gas chamber are regulated and controlled, a 6-level system is formed, the coupling of the converted microwaves and the converted laser light incident to the atom gas chamber is realized, and a coupling interface between the quantum state microwaves and the quantum state laser light is formed.

Further, the energy level of the rydberg atoms in the atom gas chamber is regulated to form a 6-level system, which is specifically as follows:

energy level |3>, energy level |4>, energy level |5> are the Reidberg energy levels, the transition laser is coupled to energy level |3> and energy level |4>, the coupling microwave is coupled to energy level |4> and energy level |5>, the probing laser and the coupling laser generate coherence during energy level transitions of energy level |1>, energy level |2> and energy level |3>, the coupling laser and the coupling microwave link microwave transitions and laser transition processes, and the transition laser is coupled to energy level |1> and energy level |6 >.

Further, the first laser outputs detection laser with its frequency locked at energy level |1>And energy level |2>On the resonance transition line of (a); the coupled laser light output by the second laser is locked in frequency at energy level |2>And energy level |3>On the resonance transition line of (a); the coupled laser coupling energy level |2 output by the second laser>And energy level |3>Is the ratio frequency omega_RAnd a detected laser coupling level |1 of said first laser output>And energy level |2>Is the ratio frequency omega_PAnd satisfies the relation: omega_R|>>|Ω_PL, |; the middle energy level |4 of the atomic gas chamber>Variation induced detuning quantity delta₄Middle energy level |5 of atomic gas cell 1>Variation induced detuning quantity delta₅And a coupled microwave coupling level |4 from the output of the first microwave source>And energy level |5>Is the ratio frequency omega_CSatisfies the relation Δ₅＝|Ω_C|²/Δ₄(ii) a The atomic gas chamber middle energy level |5>Variation induced detuning quantity delta₅Middle energy level of atomic gas cell |6>Variation induced detuning quantity delta₆And a coupled laser coupling level |5 of the second laser output>And energy level |6>Is the ratio frequency omega_ASatisfies the relation Δ₆＝|Ω_A|²/Δ₅(ii) a The bandwidth of the converted microwave is far less than the energy level |4>、|5>、|6>Variation induced detuning quantity delta₄、Δ₅、Δ₆(ii) a The frequency range of the converted microwaves is 300MHz-300 GHz; the frequency range of the auxiliary microwave output by the first microwave source is 300MHz-300GHz, and has a certain frequency difference with the frequency of the converted microwave.

The first laser outputs detection laser, the detection laser is transmitted by the first dichroic mirror, then is shaped by the first lens group, and is incident into one end of the atomic gas chamber; the second laser outputs coupled laser, is transmitted by the second dichroic mirror, is shaped by the second lens group, and is incident into the other end of the atomic gas chamber. And the end face of the first dichroic mirror and the transmission direction of the detection laser form an included angle of 45 degrees and are used for separating the coupling laser from the detection laser.

And the converted laser is incident to the end face of the second dichroic mirror through the light conversion laser separator, is shaped by the second lens group after being reflected, and is incident into the atom air chamber. And the end face of the second dichroic mirror and the transmission direction of the coupling laser form an included angle of 45 degrees, and the included angle is used for reflecting the conversion laser formed by the detection laser and the atomic gas chamber to the conversion laser separator, and the conversion laser separator filters the detection laser and outputs the conversion laser.

According to the technical scheme, the invention has the beneficial effects that:

the invention provides a microwave laser bidirectional coherent conversion device based on a rydberg atom. The device can simultaneously couple and convert microwaves and converted laser by regulating and controlling the energy level of the rydberg atoms in the atom air chamber, so that the broadband efficient bidirectional coherent conversion between the microwaves and the laser is realized, and a coupling interface between the quantum state microwaves and the quantum state laser is formed. The invention does not need resonant cavity, micro-nano device or ultra-low temperature refrigeration, and has the advantages of simple device and easy integration. The device can be used for designing a quantum radar system for microwave irradiation and laser detection processing, realizing the quantum radar which has high sensitivity and can work all day long, and obtaining the detection performance superior to the traditional radar. The invention can also be widely popularized in the fields of remote free space communication, low radiation dose medical detection and the like.

Drawings

FIG. 1 is a schematic structural diagram of a microwave laser bidirectional coherent conversion device based on a rydberg atom according to an embodiment of the invention;

FIG. 2 is a schematic diagram of a 6-level system of rydberg atoms coupled with microwaves and lasers in accordance with an embodiment of the present invention;

FIG. 3 is a schematic diagram of the tuning variation of a rydberg atom conversion laser with a probing laser frequency according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a spectrum of coherent detection signals of a rydberg atom conversion laser and a detection laser according to an embodiment of the present invention;

fig. 5 is a schematic diagram showing a phase modulation signal of a microwave according to an embodiment of the present invention, compared with a modulation signal in which a rydberg atom converts the microwave into a laser and reads out the laser.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings and examples.

In the embodiment, as shown in fig. 1, the microwave laser bidirectional coherent conversion device based on the rydberg atoms comprises an atom gas cell 1, a first laser 2, a second laser 3, a first dichroic mirror 4, a second dichroic mirror 5, a first lens group 6, a second lens group 7, a first microwave source 8 and a conversion laser separator 10.

Wherein the atomic gas cell 1 contains glass bubbles of alkali metal atomic vapor. The first laser 2 outputs detection laser, the detection laser is transmitted by the first dichroic mirror 4, shaped by the first lens group 6 and incident from one end of the atomic gas chamber 1; the second laser 3 outputs coupled laser light, which is transmitted by the second dichroic mirror 5, shaped by the second lens group 7, and enters from the other end of the atomic gas cell 1. The optical paths of the detection laser and the coupling laser in the atomic gas chamber 1 are relatively overlapped. The coupled microwaves output by the first microwave source 8 and the converted microwaves output by the second microwave source 9 are emitted to the atomic gas cell 1. The end face of the first dichroic mirror 4 and the transmission direction of the detection laser form an included angle of 45 degrees and are used for separating the coupling laser from the detection laser. The third laser 11 outputs converted laser, the converted laser is incident to the end face of the second dichroic mirror 5 through the light conversion laser separator 10, the light is reflected and then shaped by the second lens group 7, and the light is incident into the atomic gas chamber 1. The energy level of the rydberg atoms in the atom air chamber 1 is regulated to form a 6-level system, and the converted microwaves and the converted laser can be coupled at the same time to form a coupling interface between the quantum state microwaves and the quantum state laser.

An included angle of 45 degrees is formed between the end face of the second dichroic mirror 5 and the transmission direction of the coupling laser, the included angle is used for reflecting the conversion laser formed by the detection laser and the atom air chamber 1 to the conversion laser separator 10, and the conversion laser separator 10 filters the detection laser and outputs the conversion laser.

Regulating and controlling the energy level of the rydberg atoms in the atom gas chamber 1 to form a 6-level system, which is specifically as follows:

as shown in FIG. 2, energy level |3>, energy level |4>, and energy level |5> are Reedberg levels, the transition microwaves are coupled to energy level |3> and energy level |4>, and the coupled microwaves are coupled to energy level |4> and energy level |5 >; the detection laser and the coupling laser generate coherence in the energy level transition processes of energy level |1>, energy level |2> and energy level |3>, the coupling laser and the coupling microwave link the microwave transition and the laser transition processes, and the conversion laser is coupled with the energy level |1> and the energy level |6 >.

The first laser 2 outputs detection laser with its frequency locked at energy level |1>And energy level |2>On the resonance transition line of (a). The coupled laser light output by the second laser 3 is frequency-locked at energy level |2>And energy level |3>On the resonance transition line of (a). The coupled laser coupling energy level |2 output by the second laser 3>And energy level |3>Is the ratio frequency omega_RAnd a coupling level |1 of the detected laser light output from said first laser 2>And energy level |2>Is the ratio frequency omega_PAnd satisfies the relation: omega_R|>>|Ω_PL. The energy level |4 in the atomic gas cell 1>Variation induced detuning quantity delta₄Middle energy level |5 of atomic gas cell 1>Variation induced detuning quantity delta₅And a coupled microwave coupling level |4 output from the first microwave source 8>And energy level |5>Is the ratio frequency omega_CSatisfies the relation Δ₅＝|Ω_C|²/Δ₄. The energy level |5 in the atomic gas cell 1>Variation induced detuning quantity delta₅Middle energy level |6 of atomic gas cell 1>Variation induced detuning quantity delta₆And a coupled laser coupling level |5 output from said second laser 3>And energy level |6>Is the ratio frequency omega_ASatisfies the relation Δ₆＝|Ω_A|²/Δ₅. The converted microwaves output by the second microwave source 9 are coupled with the frequencies of two adjacent Reedberg energy levels |3>And |4>The converted laser light output from the third laser 11 is frequency-coupled to two adjacent energy levels |1>And |6>So that the converted microwave and the converted laser generate quantum interference. The atomic gas cell 1 is filled with an alkali metal atomic gas and is in a heat insulating state. The bandwidth of the converted microwave output by the second microwave source 9 is far less than the energy level |4>、|5>、|6>Variation induced detuning quantity delta₄、Δ₅、Δ₆. The frequency range of the converted microwaves output by the second microwave source 9 is 300MHz-300 GHz; the auxiliary microwave frequency range output by the first microwave source 8 is 300MHz-300GHz, and has a certain frequency difference with the converted microwave frequency output by the second microwave source 9, usually 30 MHz-500 MHz.

When the rydberg atoms, the microwaves and the laser parameters meet the relationship, the density of alkali metal atom steam in the atom gas chamber, the frequency output by the first microwave source 8, the frequency of the probe light and the coupling light output by the first laser 2 and the second laser 3 are adjusted, so that the rydberg atoms in the atom gas chamber 1 are regulated and controlled to form a 6-level system, a quantum interference process occurs, the conversion microwaves generate coherence in the transition of the energy level |3> and the energy level |4>, the conversion lasers generate coherence in the transition of the energy level |1> and the energy level |6>, and the conversion lasers and the conversion microwaves establish the coupling relationship.

As shown in fig. 3, a schematic diagram of the tuning variation of the rydberg atom conversion laser with the frequency of the detection laser is given, taking the resonance frequency between the |1> energy level and the |2> energy level in the atom gas cell 1 as the center, adjusting the frequency of the detection laser output by the first laser 2, and simultaneously measuring the power of the detection laser transmitted through the atom gas cell 1, the power of the conversion laser output after six-wave mixing in the atom gas cell 1, the coupling laser output by the second laser 3, the coupling microwave output by the first microwave source 8, and the conversion microwave output by the second microwave source 9, and the rydberg atoms in the atom gas cell 1 keep a resonance state. The transmitted detection laser power spectrum is shown as a square frame in the figure and presents a double-peak structure; the power spectrum of the converted laser output after six-wave mixing is shown as a circle in the figure, and a single peak structure is presented; the solid line in the figure is a theoretical simulation curve; illustrating the energy conversion between the microwave and the laser.

As shown in fig. 4, a schematic diagram of frequency spectrums of coherent detection signals of rydberg atom conversion laser and detection laser is given, and the detection laser output by the first laser 2 is modulated to form laser pulses with a pulse width of 500 μ s and a frequency shift of 10 MHz; carrying out coherent detection on the laser pulse and converted laser output after mixing with six waves in the atomic gas chamber 1, wherein a circle in the figure is a measured interference signal, and a solid line in the figure is a curve obtained by fitting according to the measured signal and accords with the | sinc | function distribution; the resulting signal spectrum shows that the switching laser frequency is determined by the resonance condition of the six-wave mixing process in the atomic gas cell 1.

As shown in fig. 5, a schematic diagram of phase modulation signals of microwaves is given, and compared with modulation signals read out by converting microwaves into laser light by using reed fort atoms, in the diagram, a solid line is a triangular phase modulation curve for performing amplitude pi and frequency 2.5KHz on the converted microwaves output by the second microwave source 9, and a dotted line is a triangular phase modulation curve for sequentially performing amplitude pi and frequency 5KHz on the converted microwaves output by the second microwave source 9; in the figure, the square frame and the round frame are respectively the recovery signals of the modulation curve; the coherence property can be effectively maintained by the microwave laser conversion process based on the rydberg atoms.

Compared with the prior art, the microwave laser bidirectional coherent conversion device based on the rydberg atoms is used, and high-efficiency conversion of microwaves and lasers can be realized by adjusting the density of alkali metal atom steam in the atom gas chamber, the frequency output by the first microwave source, the probe light output by the first laser 2 and the second laser 3 and the coupling frequency. By using the microwave laser bidirectional coherent conversion device based on the rydberg atoms, a brand-new quantum radar system for microwave irradiation and laser detection processing can be designed, high-sensitivity detection is realized, all-weather operation can be realized all day long, and the detection performance superior to that of the traditional radar is obtained.

The invention can also be widely popularized in the fields of remote free space communication, low radiation dose medical detection and the like. The microwave laser bidirectional coherent conversion device based on the rydberg atoms is used, is not limited by mode selectivity, and can realize the conversion between broadband space-time multiplexing microwave signals and laser signals. The invention uses a microwave laser bidirectional coherent conversion device based on the rydberg atoms, and can realize the conversion of time coding or orbital angular momentum coding quantum information. The microwave laser bidirectional coherent conversion device based on the rydberg atoms works in a low excitation area with extremely weak interaction between atoms, and can realize low-noise coherent conversion of microwave laser. The microwave laser bidirectional coherent conversion device based on the rydberg atoms is used, and a high-efficiency infrared camera can be used for realizing microwave imaging.

According to the introduction of the specific embodiment, the microwave laser bidirectional coherent conversion device based on the rydberg atoms has obvious effect through theoretical simulation and experimental verification; the invention is used for developing a high-sensitivity detection imaging test of a microwave irradiation optical detection system, has compact system construction, is developed in a laboratory, and can carry out a quantum detection imaging test at any time; by setting different parameters and adjusting the structure of each component, the invention can develop a quantum detection imaging test with large bandwidth and multiple frequency bands, provide technical support for the quantum radar detection imaging test, and break through the limitations of the traditional radar in the aspects of resolution and signal-to-noise ratio.