Rydberg atomic microwave electric field intensity meter laser intensity stabilization control device and method

Abstract

The invention discloses a Rydberg atomic microwave electric field intensity meter laser intensity stability control device and method, which utilizes an electro-optical liquid crystal delay device to realize the stability control of the intensity of coupled light and detection light of the Rydberg atomic microwave electric field intensity meter, thereby improving the measurement accuracy of the Rydberg atomic microwave electric field intensity meter. The method is not only beneficial to improving the laser intensity stability of the Rydberg atomic microwave electric field intensity meter, but also beneficial to the integration of the laser system, and has a clear principle, a simple structure, and is easy to realize and apply.

Description

Technical Field

[0001] The present invention relates to the field of laser intensity control, and more specifically to a laser intensity stabilization control device and method for a Rydberg atomic microwave electric field intensity meter. Background Art

[0002] The Rydberg atom microwave electric field intensity meter is a new type of microwave electric field intensity meter. It uses the EIT-AT splitting effect of the Rydberg atom to trace the microwave electric field intensity measurement to the frequency in SI units, making the microwave electric field intensity measurement not only highly accurate but also self-calibrated.

[0003] The Rydberg atom microwave electric field intensity meter is based on the EIT-AT effect of the Rydberg atom, which is extremely sensitive to laser intensity. The stability of the laser intensity plays a vital role in the accuracy of the measurement results. Usually, the Rydberg atom microwave electric field intensity meter uses a semiconductor laser with large fluctuations in output laser intensity, and optical components such as acousto-optic frequency shifters will cause fluctuations in laser intensity. In order to ensure that the Rydberg atom microwave electric field intensity meter can measure the microwave electric field intensity with high precision, it is necessary to stably control the laser intensity of the Rydberg atom microwave electric field intensity meter.

[0004] There are two methods for stable control of laser intensity at present: one is to achieve stable control of laser output laser intensity by direct feedback control of laser current port, and its typical laser intensity stability is within 10 -2 The first method is to use external intensity modulation to achieve stable control of laser intensity by feedback control of external optical devices (acoustic-optic modulator, etc.). The typical laser intensity stability is 10 -3 This method does not affect the laser frequency, but the existing traditional methods are difficult to meet the requirements of high-precision Rydberg atomic electric field intensity meter for laser intensity stability in terms of stability, integration and laser intensity stabilization speed. Summary of the invention

[0005] An object of the present invention is to provide a laser intensity stabilization control device for a Rydberg atomic microwave electric field intensity meter.

[0006] Another object of the present invention is to provide a method for stabilizing the laser intensity of a Rydberg atom microwave electric field intensity meter.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a laser intensity stabilization control device for a Rydberg atomic microwave electric field intensity meter, comprising a detection laser emitting module for emitting linearly polarized laser light, a first light splitting module for splitting the laser emitted by the detection laser emitting module into a first reference light and a first signal detection light, a first photodetector for converting the first signal detection light into a first electrical signal, a first control module for receiving the first electrical signal and controlling the laser intensity of the detection laser emitting module through the first electrical signal, and a first reflector for reflecting the first reference light;

[0009] A coupled laser emission module for emitting linearly polarized laser light, a second light splitting module for splitting the laser light emitted by the coupled laser emission module into a second reference light and a second signal detection light, a second photodetector for converting the second signal detection light into a second electrical signal, a second control module for receiving the second electrical signal and controlling the laser intensity of the detection laser emission module through the second electrical signal, and a first dichroic mirror for reflecting the second reference light;

[0010] An alkali atom gas cell for receiving the reflected first reference light and the second reference light and a microwave source module for generating a microwave electric field in the alkali atom gas cell.

[0011] Preferably, the detection laser emission module comprises a detection light laser emitter, a first isolator, a first electro-optical liquid crystal retarder and a first polarizer which are sequentially arranged along the laser light path emitted by the detection light laser;

[0012] The coupled laser emission module comprises a coupled light laser emitter, a second isolator, a second electro-optical liquid crystal retarder and a second polarizer which are sequentially arranged along the laser light path emitted by the coupled light laser.

[0013] Preferably, the first light splitting module comprises a first half wave plate and a first Glan prism which are sequentially arranged along the laser light path emitted by the detection light laser;

[0014] The second light splitting module includes a second half wave plate and a second Glan prism which are sequentially arranged along the laser light path emitted by the coupling light laser.

[0015] Preferably, the first photodetector, the first control module and the first electro-optical liquid crystal retarder are electrically connected in sequence, and the first control module controls the laser intensity of the detection laser emission module by controlling the voltage loaded on the first electro-optical liquid crystal retarder;

[0016] The second photodetector, the second control module and the second electro-optical liquid crystal retarder are electrically connected in sequence, and the second control module controls the laser intensity of the coupled laser emission module by controlling the voltage loaded on the second electro-optical liquid crystal retarder.

[0017] Preferably, the detection laser emission module further includes a third spectroscopic module, a second reflector and a saturation absorption spectrum module;

[0018] Among them, the third splitter module is configured between the first isolator and the first electro-optical liquid crystal delay device along the laser light path emitted by the detection light laser, and is used to split the laser emitted by the detection light laser into main path light and slave path light, the main path light enters the first electro-optical liquid crystal delay device; the slave path light enters the saturated absorption spectrum module through the second reflector; the saturated absorption spectrum module controls the detection light laser by receiving the slave path light, so that the laser frequency emitted by the detection light laser is locked on the atomic transition line.

[0019] Preferably, the detection laser emission module further comprises an acousto-optic frequency shifter, which is arranged between the third light splitting module and the first electro-optical liquid crystal delay device along the laser light path emitted by the detection light laser, and is used to control the laser frequency of the main light path.

[0020] Preferably, the third light splitting module comprises a third half wave plate and a third Glan prism, and the third half wave plate and the third Glan prism are sequentially arranged along the laser light path emitted by the detection light laser.

[0021] Preferably, the detection laser emission module further includes a fourth half wave plate, which is arranged between the detection light laser and the first isolator and is used to match the polarization of the first isolator;

[0022] The coupled laser emission module further includes a fifth half-wave plate, which is disposed between the coupled light laser and the second isolator and is used to match the polarization of the second isolator.

[0023] Preferably, the detection laser emission module also includes a light baffle, which is arranged between the acousto-optic frequency shifter and the first electro-optical liquid crystal delay device along the laser light path emitted by the detection light laser, and is used to isolate the stray light generated by the diffraction of the acousto-optic frequency shifter from entering the first electro-optical liquid crystal delay device.

[0024] In a second aspect, the present invention provides a method for stabilizing the laser intensity of a Rydberg atomic microwave electric field intensity meter, comprising the following steps:

[0025] S1. Assemble the laser intensity stabilization control device of the Rydberg atomic microwave electric field intensity meter in sequence, the microwave source module emits the microwave electric field, the detection light laser and the coupling light laser emit the detection light and the coupling light respectively;

[0026] S2, removing the first electro-optical liquid crystal retarder and the second electro-optical liquid crystal retarder, rotating the first polarizer so that the intensity of the detection light passing through the first polarizer is at a minimum state, and rotating the second polarizer so that the intensity of the coupled light passing through the second polarizer is at a minimum state;

[0027] S3, reinstalling the first electro-optical liquid crystal retarder and the second electro-optical liquid crystal retarder in the optical path, rotating the first electro-optical liquid crystal retarder so that the intensity of the detection light passing through the first analyzer is at a maximum state, and rotating the second electro-optical retarder so that the intensity of the coupled light passing through the second analyzer is at a maximum state;

[0028] S4, using the first light splitting module, splitting the detection light into a first reference light and a first signal detection light, the first signal detection light enters the first photodetector and is converted into a first electrical signal; using the second light splitting module, splitting the coupled light into a second reference light and a second signal detection light, the second signal detection light enters the second photodetector and is converted into a second electrical signal;

[0029] S5, the first electrical signal enters the first control module, the amplitude change of the first electrical signal is analyzed, the voltage loaded on both ends of the first electro-optical liquid crystal retarder is controlled by the first control module, the intensity of the detection light emitted by the first electro-optical liquid crystal retarder is changed, so that the intensity of the detection light is in a stable state; the second electrical signal enters the second control module, the amplitude change of the second electrical signal is analyzed, the voltage loaded on both ends of the second electro-optical liquid crystal retarder is controlled by the second control module, the intensity of the coupled light emitted by the second electro-optical liquid crystal retarder is changed, so that the intensity of the coupled light is in a stable state;

[0030] S6. Adjust the positions of the first reflector and the first dichroic mirror to reflect the first reference light and the second reference light that have been controlled and stabilized into the alkali atom gas chamber.

[0031] The beneficial effects of the present invention are as follows:

[0032] The purpose of the present invention is to provide a Rydberg atomic microwave electric field intensity meter laser intensity stability control device and method, by controlling the electro-optical liquid crystal delay device loading voltage, to achieve stable control of laser intensity, the method can achieve laser intensity 10 -4 It has a stability of orders of magnitude. It has a clear principle, simple structure, and is easy to integrate. It can achieve stable control of the laser intensity of the Rydberg atomic electric field intensity meter, greatly improving the measurement accuracy of the electric field intensity meter. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 The figure shows a schematic diagram of the structure of the laser intensity stabilization control device of the present invention.

[0035] Figure numerals, 1, detection light laser; 2, fourth half-wave plate; 3, first isolator; 4, third half-wave plate; 5, third Glan prism; 6, second reflector; 7, saturated absorption spectrum module; 8, acousto-optic frequency shifter; 9, light blocking plate; 10, first electro-optic liquid crystal retarder; 11, first control module; 12, first analyzer; 13, first half-wave plate; 14, first Glan prism; 15, first photodetector; 16, first reflector; 17, alkali atom gas chamber; 18, microwave source module; 19, first dichroic mirror; 20, second photodetector; 21, second Glan prism; 22, second half-wave plate; 23, second analyzer; 24, second control module; 25, second electro-optic liquid crystal retarder; 26, second isolator; 27, fifth half-wave plate; 28, coupled light laser. DETAILED DESCRIPTION

[0036] To make the technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0037] It should be noted that the term [the embodiment of the present invention does not limit the execution order of steps a to e. For example, step c and step a may be executed in sequence]

[0038] [All numerical values ​​specified in the present invention (such as temperature, time, concentration and weight, etc., including ranges of each thereof) can generally be appropriately changed by (+) or (-) approximate values ​​in increments of 0.1 or 1.0. All numerical values ​​specified can be understood as being preceded by the term "about". ]

[0039] Example

[0040] like Figure 1As shown, a Rydberg atomic microwave electric field intensity meter laser intensity stabilization control device, the linear polarization detection light emitted by the detection light laser 1 passes through the fourth half wave plate 2 and the first isolator 3, ensuring that the working mode of the detection light laser 1 is not affected by the subsequent optical path feedback; the detection light passes through the third half wave plate 4 and the third Glan prism 5 to be divided into two beams of light, one beam is the main path light, and the other beam is the slave path light. After the slave path light is reflected by the second reflector 6, the saturated absorption spectrum module 7 is used to lock the detection light frequency on the atomic transition line to achieve long-term stability of the detection light laser frequency, the main path light passes through the acousto-optic frequency shifter 8 to achieve precise control of the detection light laser frequency, and the light baffle is used to isolate the stray light generated by the diffraction of the acousto-optic frequency shifter 8 from entering the subsequent optical element;

[0041] Without installing the first electro-optical liquid crystal retarder 10, the main path light passing through the acousto-optic frequency shifter 8 is directly passed through the first analyzer 12, and the first analyzer 12 is rotated so that the light intensity of the main path light passing through the first analyzer 12 is minimized.

[0042] The first electro-optical liquid crystal retarder 10 is installed in the optical path, so that the main light passing through the acousto-optic frequency shifter 8 enters the first polarizer 12 after passing through the first electro-optical liquid crystal retarder 10, and the first electro-optical liquid crystal retarder 10 is rotated so that the main light passing through the first polarizer 12 is emphasized to the maximum.

[0043] The main path light passing through the first polarizer 12 is divided into two beams through the first half wave plate 13 and the first Glan prism 14 in sequence, one beam is the first reference light, and the other beam is the first signal detection light. The first signal detection light enters the first photodetector 15, and the first photodetector 15 converts the optical signal into an electrical signal, and then inputs the electrical signal into the first control module 11. The first control module 11 controls the voltage amplitude of the first electro-optical liquid crystal retarder 10 to realize PID feedback control of the detection light laser intensity. The first reference light enters the alkali atom gas chamber 17 through the first reflector 16, and reacts with the De Pauw atoms in the alkali atom gas chamber 17.

[0044] The linearly polarized coupling light emitted by the coupling light laser 28 passes through the fifth half-wave plate 27 and the second isolator 26, ensuring that the working mode of the coupling light laser 28 is not affected by the subsequent optical path feedback;

[0045] Without installing the second electro-optical liquid crystal retarder 25, the coupled light is directly passed through the second analyzer 23, and the second analyzer 23 is rotated to minimize the intensity of the main path light when it passes through the second analyzer 23.

[0046] The second electro-optical liquid crystal retarder 25 is installed in the optical path, so that the coupled light enters the second polarizer 23 after passing through the second electro-optical liquid crystal retarder 25, and the second electro-optical liquid crystal retarder 25 is rotated so that the main path light passing through the second polarizer 23 is emphasized to the maximum.

[0047] The main path light passing through the second polarizer 23 is divided into two beams through the second half wave plate 22 and the second Glan prism 21 in sequence, one beam is the second reference light, and the other beam is the second signal detection light. The second signal detection light enters the second photodetector 20, and the second photodetector 20 converts the optical signal into an electrical signal, and then inputs the electrical signal into the second control module 24. The second control module 24 controls the voltage amplitude of the second electro-optical liquid crystal retarder 25 to realize PID feedback control of the coupled light laser intensity. The second reference light enters the alkali atom gas chamber 17 through the first dichroic mirror 19, and reacts with the De Pauw atoms in the alkali atom gas chamber 17.

[0048] The microwave source module 18 is used to generate a microwave electric field in the alkali atom gas chamber 17;

[0049] The first reference light passing through the alkali atom gas cell 17 may be transmitted through the first dichroic mirror 19 . At this time, the field intensity of the alkali atom gas cell may be known by acquiring the transmitted first reference light.

[0050] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A Rydberg atomic microwave electric field intensity meter laser intensity stabilization control method using a Rydberg atomic microwave electric field intensity meter laser intensity stabilization control device, characterized in that: The control device includes a detection laser emitting module for emitting linearly polarized laser light, a first light splitting module for splitting the laser light emitted by the detection laser emitting module into a first reference light and a first signal detection light, a first photodetector for converting the first signal detection light into a first electrical signal, a first control module for receiving the first electrical signal and controlling the laser intensity of the detection laser emitting module through the first electrical signal, and a first reflector for reflecting the first reference light; A coupled laser emission module for emitting linearly polarized laser light, a second light splitting module for splitting the laser light emitted by the coupled laser emission module into a second reference light and a second signal detection light, a second photodetector for converting the second signal detection light into a second electrical signal, a second control module for receiving the second electrical signal and controlling the laser intensity of the detection laser emission module through the second electrical signal, and a first dichroic mirror for reflecting the second reference light; an alkali atom gas cell for receiving the reflected first reference light and second reference light, and a microwave source module for generating a microwave electric field in the alkali atom gas cell; The detection laser emission module includes a detection light laser, a first isolator, a first electro-optical liquid crystal retarder and a first polarizer which are sequentially arranged along the laser light path emitted by the detection light laser; The coupled laser emission module comprises a coupled light laser, a second isolator, a second electro-optical liquid crystal retarder and a second polarizer which are sequentially arranged along the laser light path emitted by the coupled light laser; The first light splitting module comprises a first half wave plate and a first Glan prism which are sequentially arranged along the laser light path emitted by the detection light laser; The second light splitting module comprises a second half wave plate and a second Glan prism which are sequentially arranged along the laser light path emitted by the coupled light laser; The first photodetector, the first control module and the first electro-optical liquid crystal retarder are electrically connected in sequence, and the first control module controls the laser intensity of the detection laser emission module by controlling the voltage loaded on the first electro-optical liquid crystal retarder; The second photodetector, the second control module and the second electro-optical liquid crystal retarder are electrically connected in sequence, and the second control module controls the laser intensity of the coupled laser emission module by controlling the voltage loaded on the second electro-optical liquid crystal retarder; The detection laser emission module also includes a third light splitting module, a second reflector and a saturation absorption spectrum module; The third light splitting module is configured between the first isolator and the first electro-optical liquid crystal retarder along the laser light path emitted by the detection light laser, and is used to split the laser emitted by the detection light laser into main light and slave light, wherein the main light enters the first electro-optical liquid crystal retarder; the slave light passes through the second reflector and enters the saturated absorption spectrum module; the saturated absorption spectrum module controls the detection light laser by receiving the slave light, so that the laser frequency emitted by the detection light laser is locked on the atomic transition line; The detection laser emission module further includes an acousto-optic frequency shifter, which is arranged between the third light splitting module and the first electro-optical liquid crystal delay device along the laser light path emitted by the detection light laser, and is used to control the laser frequency of the main light path; The third light splitting module comprises a third half wave plate and a third Glan prism, and the third half wave plate and the third Glan prism are sequentially arranged along the laser light path emitted by the detection light laser; The detection laser emission module further includes a fourth half-wave plate, which is disposed between the detection light laser and the first isolator and is used to match the polarization of the first isolator; The coupled laser emission module further includes a fifth half-wave plate, which is disposed between the coupled light laser and the second isolator and is used to match the polarization of the second isolator; The detection laser emission module further includes a light baffle, which is arranged between the acousto-optic frequency shifter and the first electro-optical liquid crystal retarder along the laser light path emitted by the detection light laser, and is used to isolate the stray light generated by the diffraction of the acousto-optic frequency shifter from entering the first electro-optical liquid crystal retarder; The method comprises the following steps: S1. Assemble the laser intensity stabilization control device of the Rydberg atomic microwave electric field intensity meter in sequence, the microwave source module emits the microwave electric field, the detection light laser and the coupling light laser emit the detection light and the coupling light respectively; S2, removing the first electro-optical liquid crystal retarder and the second electro-optical liquid crystal retarder, rotating the first polarizer so that the intensity of the detection light passing through the first polarizer is at a minimum state, and rotating the second polarizer so that the intensity of the coupled light passing through the second polarizer is at a minimum state; S3, reinstall the first electro-optical liquid crystal retarder and the second electro-optical liquid crystal retarder in the optical path, rotate the first electro-optical liquid crystal retarder so that the intensity of the detection light passing through the first polarizer is at the maximum state, and rotate the second electro-optical retarder so that the intensity of the coupled light passing through the second polarizer is at the maximum state; S4, divide the detection light into a first reference light and a first signal detection light through the first light splitting module, the first signal detection light enters the first photodetector and is converted into a first electrical signal; divide the coupled light into a second reference light and a second signal detection light through the second light splitting module, the second signal detection light enters the second photodetector and is converted into a second electrical signal; S5, the first electrical signal enters the first control module, the amplitude change of the first electrical signal is analyzed, the voltage loaded on both ends of the first electro-optical liquid crystal retarder is controlled by the first control module, the intensity of the detection light emitted by the first electro-optical liquid crystal retarder is changed, so that the intensity of the detection light is in a stable state; the second electrical signal enters the second control module, the amplitude change of the second electrical signal is analyzed, the voltage loaded on both ends of the second electro-optical liquid crystal retarder is controlled by the second control module, the intensity of the coupled light emitted by the second electro-optical liquid crystal retarder is changed, so that the intensity of the coupled light is in a stable state; S6. Adjust the positions of the first reflector and the first dichroic mirror to reflect the first reference light and the second reference light that have been controlled and stabilized into the alkali atom gas chamber.

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