Optical fiber reflection type Rydberg atomic electric field detection device and method

Abstract

The invention provides an optical fiber reflection-type Rydberg atomic electric field detection device, and the device comprises a detection light transmitting optical fiber which is used for transmitting a first detection laser beam; the second parabolic reflector is used for deflecting and collimating the first detection laser beam to form a collimated detection laser beam; the coupling light emitting optical fiber is used for emitting a coupling laser beam; the first parabolic reflector is used for deflecting and collimating the coupled laser beam to form a collimated coupled laser beam and a collimated detection laser beam, and the collimated coupled laser beam is used for jointly exciting alkali metal atoms in the atomic gas chamber to form a second detection laser beam; the first parabolic reflector is also used for separating the coupling laser beam and the second detection laser beam, and deflecting, converging and collimating the second detection laser beam to form a parallel detection laser beam; and the detection light receiving optical fiber is used for receiving the parallel detection light beams and reading microwave electric field information. The optical fiber reflection type Rydberg atomic electric field detection device is small in number of optical elements, short in optical path length, small in size and high in integration level.

Description

Technical Field

[0001] This invention relates to the field of electric field detection, and in particular to a fiber-optic reflective Rydberg atom electric field detection device and method. Background Technology

[0002] Recently, the electric field detection method of Rydberg atoms has been fully proven in principle, which can convert the measurement of microwave electric field amplitude into the measurement of laser frequency. As a new generation of electric field metrology standard technology system, it has been verified in principle demonstration experiments and is being studied as a potential reserve technology by many domestic research institutes and enterprises. Key technology breakthroughs are underway. The probe (detection device) is the core component and needs to meet engineering requirements such as small size, high signal-to-noise ratio, detection of electric field polarization, portability, and easy installation. Some research institutions have fabricated fiber optic probes, but they suffer from problems such as low detection efficiency, large structural size, complex fiber optic interface layout, and inability to test electric field polarization matching. Especially in situations where probe rotation is required, the pigtail of the straight-through probe has the risk of twisting, affecting the polarization characteristics of laser transmission inside the fiber and causing distortion of microwave electric field polarization information detection.

[0003] Therefore, there is an urgent need for a fiber-optic Rydberg atomic electric field detection device that can deflect the optical path at the end face of the gas cell, reduce the number of optical path components, and improve integration. Summary of the Invention

[0004] This invention provides a fiber-optic Rydberg atomic electric field detection device, comprising:

[0005] The probe light emitting fiber is set vertically and is used to emit the first probe laser beam;

[0006] The second parabolic reflector, whose axis of symmetry is in the horizontal direction, is used to deflect and collimate the first detection laser beam to form a collimated detection laser beam.

[0007] The coupling light emitting fiber is set vertically and is used to emit the coupled laser beam;

[0008] The first parabolic reflector, whose axis of symmetry is in the horizontal direction, is used to deflect and collimate the coupled laser beam to form a collimated coupled laser beam.

[0009] The atomic gas chamber is set horizontally between the probe light emitting fiber and the coupling light emitting fiber. One end receives the collimated probe laser beam, and the other end receives the collimated coupling laser beam. The collimated probe laser beam and the collimated coupling laser beam are used to jointly excite the alkali metal atoms in the atomic gas chamber to generate atoms with corresponding Rydberg energy levels for detecting microwave electric fields. The collimated probe laser beam carrying the atoms forms a second probe laser beam and is transmitted out of the atomic gas chamber.

[0010] in,

[0011] The first parabolic reflector is also used to separate the coupled laser beam and the second probe laser beam, and to deflect, converge and collimate the second probe laser beam to form a parallel probe beam.

[0012] The probe light receiving fiber is set vertically to receive the parallel probe beam and read microwave electric field information.

[0013] Furthermore, the second parabolic mirror includes:

[0014] The main body of the parabolic reflector;

[0015] The inner surface is coated with a high-reflectivity film to deflect and collimate the first detection laser beam, forming a collimated detection laser beam.

[0016] Furthermore, the fiber end face of the probe light emitting fiber is positioned at the focal point of the second parabolic reflector.

[0017] Furthermore, the first parabolic mirror includes:

[0018] The main body of the parabolic reflector;

[0019] The inner surface is polished and coated with a beam-splitting film to separate the coupled laser beam and the second detection laser beam;

[0020] The outer surface is coated with a high-reflectivity film to deflect, converge, and collimate the second probe laser beam, forming a parallel probe beam.

[0021] Furthermore, the outer parabolic surface is a total internal reflection parabolic surface.

[0022] Furthermore, the fiber end faces of the probe light receiving fiber and the coupling light emitting fiber are respectively located at the first focal point and the second focal point of the first parabolic reflector.

[0023] Furthermore, the collimated detection laser beam and the collimated coupling laser beam propagate along the same optical axis within the atomic gas chamber.

[0024] Furthermore, let the diameter of the collimated detection laser beam be D1 and the diameter of the collimated coupling laser beam be D2, then D1 < D2.

[0025] Furthermore, the fiber-optic reflective Rydberg atomic electric field detection device also includes: a shell, which is a cylindrical shell with its axis along the vertical direction, an antenna is arranged at the radial position of the cylindrical shell, the aperture of the antenna is aligned with the axis of symmetry of the first parabolic reflector and the second parabolic reflector, the polarization direction of the antenna is vertical, and the polarization directions of the first detection laser beam and the coupling laser beam are also vertical.

[0026] This invention also provides a fiber-optic reflection-based method for detecting the electric field of Rydberg atoms, comprising the following steps:

[0027] Firing the first detection laser beam;

[0028] The first detection laser beam is deflected and collimated to form a collimated detection laser beam;

[0029] Emitting a coupled laser beam;

[0030] The coupled laser beam is deflected and collimated to form a collimated coupled laser beam;

[0031] The collimated probe laser beam and the collimated coupling laser beam jointly excite alkali metal atoms to generate atoms with corresponding Rydberg energy levels for detecting microwave electric fields. The collimated probe laser beam carrying the atoms forms a second probe laser beam.

[0032] The coupling laser beam and the second probe laser beam are separated, and the second probe laser beam is deflected, focused, and collimated to form a parallel probe beam.

[0033] It receives a parallel probe beam and reads microwave electric field information.

[0034] The fiber-optic reflective Rydberg atomic electric field detection device provided by this invention employs a second parabolic reflector and a first parabolic reflector, which can replace three independent optical elements: a dichroic beam splitter, a reflector, and a collimating mirror. This achieves optical path deflection at the gas cell end face, reduces the number of optical elements, shortens the optical path length, reduces the overall size, and achieves high integration. The polarization directions of the first detection laser beam and the coupling laser beam are both vertical. The detection light emitting fiber, the coupling light emitting fiber, and the detection light receiving fiber are all arranged vertically. The atomic gas cell is arranged horizontally, enabling it to receive microwave electric fields incident at any angle in the horizontal direction. During omnidirectional detection, the vertical direction is fixed, allowing for vertical... With the vertical direction as the fixed axis, the horizontally rotating fiber-reflective Rydberg atomic electric field detector can complete the technical performance test of omnidirectional field strength measurement, avoiding fiber winding twisting and improving stability. The first parabolic reflector can achieve reflective collimation of the coupled laser beam, reducing the optical loss and aberration of the coupled laser beam. By setting the fiber end face of the probe light emitting fiber at the focal point of the second parabolic reflector, the probe laser beam can be emitted more efficiently. By setting the fiber end faces of the probe light receiving fiber and the coupled light emitting fiber at the first and second focal points of the first parabolic reflector, respectively, the parallel probe beam can be received and the coupled laser beam can be emitted more efficiently.

[0035] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and accompanying drawings. Attached Figure Description

[0036] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the following drawings:

[0037] Figure 1 This is a schematic diagram of the structure of a fiber-optic reflective Rydberg atomic electric field detection device according to an embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of the structure of the first parabolic reflector in a fiber-optic reflective Rydberg atomic electric field detection device according to an embodiment of the present invention.

[0039] Figure 3 This is a flowchart of a fiber-optic reflective Rydberg atomic electric field detection method according to an embodiment of the present invention;

[0040] Figure label:

[0041] 10: Probe light receiving fiber; 20: Coupled light emitting fiber; 30: First parabolic reflector; 301: Outer parabolic surface; 302: Parabolic reflector body; 303: Inner parabolic surface; 304: Inner parabolic surface trend line; 306: First focal point; 305: Second focal point; 40: Outer shell; 50: Atomic gas chamber; 60: Second parabolic reflector; 70: Probe light emitting fiber; 80: Antenna. Detailed Implementation

[0042] To address the technical problem that the pigtail of a straight-through probe may be twisted when probe rotation is required, affecting the polarization characteristics of laser transmission inside the optical fiber and causing distortion of microwave electric field polarization information detection, a fiber-optic reflective Rydberg atomic electric field detection device is provided.

[0043] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention. Furthermore, the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0044] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of the embodiments of the present invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than that illustrated or described herein.

[0045] Figure 1 This is a schematic diagram of a fiber-optic reflective Rydberg atomic electric field detection device according to an embodiment of the present invention. (See attached diagram.) Figure 1 The fiber-optic reflective Rydberg atomic electric field detection device includes:

[0046] The probe light emitting fiber 70 is set vertically and is used to emit the first probe laser beam;

[0047] The second parabolic reflector 60, whose axis of symmetry is in the horizontal direction, is used to deflect and collimate the first detection laser beam to form a collimated detection laser beam.

[0048] The coupling light emitting fiber 20 is arranged vertically and is used to emit the coupled laser beam;

[0049] The first parabolic reflector 30, whose axis of symmetry is in the horizontal direction, is used to deflect and collimate the coupled laser beam to form a collimated coupled laser beam.

[0050] The atomic gas chamber 50 is arranged horizontally between the probe light emitting fiber 70 and the coupling light emitting fiber 20. One end receives the collimated probe laser beam and the other end receives the collimated coupling laser beam. The collimated probe laser beam and the collimated coupling laser beam are used to jointly excite the alkali metal atoms in the atomic gas chamber 50 to generate atoms with corresponding Rydberg energy levels for detecting microwave electric fields. The collimated probe laser beam carrying the aforementioned atoms forms a second probe laser beam and is transmitted out of the atomic gas chamber 50.

[0051] The first parabolic reflector 30 is also used to separate the coupled laser beam and the second probe laser beam, and to deflect, converge and collimate the second probe laser beam to form a parallel probe beam.

[0052] The probe light receiving fiber 10 is set vertically to receive the parallel probe beam and read microwave electric field information.

[0053] Specifically, both the probe light emitting fiber 70 and the coupling light emitting fiber 20 are polarization-maintaining fibers with small numerical apertures.

[0054] Specifically, the wavelength of the first probe laser beam is 852 nm, and its frequency resonates with the D2 transition line of alkali metal atoms such as cesium atoms.

[0055] Specifically, the wavelength of the coupled laser beam is 507nm to 513nm. The specific wavelength value corresponds to different Rydberg atomic energy levels and is selected accordingly. In this embodiment, it is 509nm.

[0056] Specifically, the second parabolic reflector 60 includes:

[0057] The main body of the parabolic reflector;

[0058] The inner surface is coated with a high-reflectivity film to deflect and collimate the first detection laser beam, forming a collimated detection laser beam.

[0059] Specifically, the fiber end face of the probe light emitting fiber 70 is set at the focal point of the second parabolic reflector 60. Since any light incident on the parabolic surface will pass through the focal point of the parabolic surface after reflection, the probe laser beam can be emitted more efficiently.

[0060] Figure 2 This is a schematic diagram of the structure of the first parabolic reflector in a fiber-optic reflective Rydberg atomic electric field detection device according to an embodiment of the present invention. See also... Figure 2 The structure of the first parabolic reflector 30 is similar to that of the second parabolic reflector 60, including:

[0061] Parabolic reflector body 302;

[0062] The inner parabolic surface 303 is coated with a beam-splitting film to separate the coupled laser beam and the second detection laser beam. Its trend line 304 extends along the parabola corresponding to the inner parabolic surface 303.

[0063] The outer surface 301 is coated with a high-reflectivity film, which is used to deflect, converge, and collimate the second detection laser beam to form a parallel detection beam.

[0064] Furthermore, the fiber end faces of the probe light receiving fiber 10 and the coupling light emitting fiber 20 are respectively set at the first focal point 306 and the second focal point 305 of the first parabolic reflector 30. As mentioned above, this enables the parallel probe beam to be received and the coupling laser beam to be emitted more efficiently.

[0065] Furthermore, the outer parabolic surface 301 is a total reflection parabolic surface, ensuring that the second detection laser beam forms total reflection on the outer parabolic surface 301.

[0066] Specifically, the polarization directions of the first detection laser beam and the coupling laser beam are both vertical.

[0067] Specifically, the deflection angles of the first probe laser beam, the coupling laser beam, and the second probe laser beam are all 90°.

[0068] Specifically, the spot size of the parallel probe beam is less than 8 μm.

[0069] Specifically, the collimated detection laser beam and the collimated coupling laser beam propagate along the same optical axis within the atomic gas chamber 50.

[0070] Furthermore, let the diameter of the collimated probe laser beam be D1 and the diameter of the collimated coupling laser beam be D2, then D1 < D2. The smaller diameter of the collimated probe laser beam ensures that when the collimated probe laser beam and the collimated coupling laser beam propagate along the same optical axis within the atomic gas cell 50, the collimated coupling laser beam always completely covers the collimated probe laser beam. This results in the alkali metal atoms excited by the collimated probe laser beam being excited to the Rydberg level to the maximum extent possible by the collimated coupling laser beam, thereby improving the detection sensitivity and accuracy of the microwave electric field.

[0071] Specifically, the fiber-optic reflective Rydberg atomic electric field detection device further includes:

[0072] The outer shell 40 is a cylindrical shell with its axis along the vertical direction. An antenna 80 is arranged radially on the cylindrical shell. The aperture of the antenna 80 is aligned with the axis of symmetry of the first parabolic reflector 30 and the second parabolic reflector 60. The polarization direction of the antenna 80 is vertical, so that the antenna 80 can receive the microwave electric field emitted axially in 360° around the outer shell, thereby expanding the receiving range of the microwave electric field.

[0073] See Figure 2 The coupled laser beam emitted by the coupling optical transmitting fiber 20 is in a divergent state. The degree of divergence is determined by the numerical aperture NA and mode field diameter DMF of the coupling optical transmitting fiber 20. The coupled laser beam is a Gaussian beam, which is deflected by 90° after reflection by the inner parabolic surface 303, resulting in a collimation effect. The divergence angle becomes smaller, and it can be approximated as a parallel beam. Its approximate divergence angle is [value missing]. The beam diameter of the collimated laser beam, in terms of 1 / e 2 The energy of the beam is equal to the radius of the Gaussian beam. Wherein, RFL represents the distance between the axis of symmetry of the first parabolic mirror 30 and the optical axis.

[0074] The analysis of the first probe laser beam in the probe light emitting fiber 70 and the second parabolic reflector 60 is similar to the above analysis and will not be repeated.

[0075] In summary, the fiber-optic reflective Rydberg atomic electric field detection device provided in this embodiment of the invention employs a second parabolic reflector 60 and a first parabolic reflector 30, which can replace three independent optical elements: a dichroic beam splitter, a reflector, and a collimating mirror. This achieves optical path deflection at the gas cell end face, reduces the number of optical elements, shortens the optical path length, reduces the overall size, and achieves high integration. The polarization directions of the first detection laser beam and the coupling laser beam are both vertical. The detection light emitting fiber 70, the coupling light emitting fiber 20, and the detection light receiving fiber 10 are all arranged vertically, while the atomic gas cell 50 is arranged horizontally. This allows it to receive microwave electric fields incident at any angle in the horizontal direction. During omnidirectional detection, the vertical direction is fixed. With the vertical direction as the fixed axis, the horizontal rotation of the fiber-optic reflective Rydberg atomic electric field detector can complete the omnidirectional technical performance test of field strength measurement, avoiding fiber winding twisting and improving stability. The first parabolic reflector 30 can achieve reflective collimation of the coupled laser beam, reducing the optical loss and aberration of the coupled laser beam. By setting the fiber end face of the probe light emitting fiber 70 at the focal point of the second parabolic reflector 60, the probe laser beam can be emitted more efficiently. By setting the fiber end faces of the probe light receiving fiber 10 and the coupled light emitting fiber 20 at the first focal point 306 and the second focal point 305 of the first parabolic reflector 30, respectively, the parallel probe beam can be received and the coupled laser beam can be emitted more efficiently.

[0076] This invention also provides a fiber-optic reflection-based method for detecting the electric field of Rydberg atoms, comprising the following steps:

[0077] Firing the first detection laser beam;

[0078] The first detection laser beam is deflected and collimated to form a collimated detection laser beam;

[0079] Emitting a coupled laser beam;

[0080] The coupled laser beam is deflected and collimated to form a collimated coupled laser beam;

[0081] The collimated probe laser beam and the collimated coupling laser beam jointly excite alkali metal atoms to generate atoms with corresponding Rydberg energy levels for detecting microwave electric fields. The collimated probe laser beam carrying the aforementioned atoms forms a second probe laser beam.

[0082] The coupling laser beam and the second probe laser beam are separated, and the second probe laser beam is deflected, focused, and collimated to form a parallel probe beam.

[0083] It receives a parallel probe beam and reads microwave electric field information.

[0084] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0085] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A fiber-optic reflective Rydberg atomic electric field detection device, characterized in that, include: The probe light emitting fiber (70) is set vertically and is used to emit the first probe laser beam; The second parabolic reflector (60), whose axis of symmetry is in the horizontal direction, is used to deflect and collimate the first detection laser beam to form a collimated detection laser beam; The coupling light emitting fiber (20) is set in the vertical direction and is used to emit the coupled laser beam; The first parabolic reflector (30), whose axis of symmetry is in the horizontal direction, is used to deflect and collimate the coupled laser beam to form a collimated coupled laser beam; An atomic gas chamber (50) is arranged horizontally between the probe light emitting fiber (70) and the coupling light emitting fiber (20). One end receives the collimated probe laser beam, and the other end receives the collimated coupling laser beam. The collimated probe laser beam and the collimated coupling laser beam are used to jointly excite the alkali metal atoms in the atomic gas chamber (50) to generate atoms with corresponding Rydberg energy levels for detecting microwave electric fields. The collimated probe laser beam carrying the atoms forms a second probe laser beam and is transmitted out of the atomic gas chamber (50). in, The first parabolic reflector (30) is also used to separate the coupled laser beam and the second probe laser beam, and to deflect, converge and collimate the second probe laser beam to form a parallel probe beam; The probe light receiving fiber (10) is set in the vertical direction to receive the parallel probe beam and read microwave electric field information.

2. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 1, characterized in that, The second parabolic mirror (60) includes: The main body of the parabolic reflector; The inner surface is coated with a high-reflectivity film to deflect and collimate the first detection laser beam, forming the collimated detection laser beam.

3. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 2, characterized in that, The fiber end face of the probe light emitting fiber (70) is located at the focal point of the second parabolic reflector (60).

4. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 1, characterized in that, The first parabolic reflector (30) includes: Parabolic reflector body (302); The inner surface (303) is coated with a beam-splitting film for separating the coupled laser beam and the second detection laser beam; The outer surface (301) is coated with a high-reflectivity film to deflect, converge, and collimate the second detection laser beam to form the parallel detection beam.

5. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 4, characterized in that, The outer parabolic surface (301) is a total reflection parabolic surface.

6. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 5, characterized in that, The fiber end faces of the probe light receiving fiber (10) and the coupling light emitting fiber (20) are respectively disposed at the first focal point (306) and the second focal point (305) of the first parabolic reflector (30).

7. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 1, characterized in that, The collimated probe laser beam and the collimated coupled laser beam are transmitted along the same optical axis within the atomic gas cell (50).

8. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 7, characterized in that, Let the diameter of the collimated detection laser beam be D1 and the diameter of the collimated coupling laser beam be D2, then D1 < D2.

9. The fiber-optic reflective Rydberg atomic electric field detection device according to claim 1, characterized in that, Also includes: The outer shell (40) is a cylindrical shell with its axis along the vertical direction. An antenna (80) is arranged at the radial position of the cylindrical shell. The aperture of the antenna (80) is aligned with the axis of symmetry of the first parabolic reflector (30) and the second parabolic reflector (60). The polarization direction of the antenna (80) is vertical. The polarization directions of the first detection laser beam and the coupling laser beam are also vertical.

10. A fiber-optic reflection-based method for detecting the electric field of Rydberg atoms, characterized in that, Includes the following steps: Firing the first detection laser beam; The first detection laser beam is deflected and collimated to form a collimated detection laser beam; Emitting a coupled laser beam; The coupled laser beam is deflected and collimated to form a collimated coupled laser beam; The collimated probe laser beam and the collimated coupling laser beam jointly excite alkali metal atoms to generate atoms with corresponding Rydberg energy levels for detecting microwave electric fields. The collimated probe laser beam carrying the atoms forms a second probe laser beam. The coupled laser beam and the second probe laser beam are separated, and the second probe laser beam is deflected, focused, and collimated to form a parallel probe beam; The parallel probe beam is received, and microwave electric field information is read.

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