Quantum sensor depolarization common-mode noise method and system

Abstract

The invention provides a quantum sensor depolarization common-mode noise method and system. Laser emitted by a detection light source is divided into first polarized light and second polarized light after passing through a first polarization splitting prism, and second detection light emitted from an atomic gas chamber is divided into third polarized light and fourth polarized light after passing through a second polarization splitting prism; the first differentiator is used for differentiating detection signals output by the first photoelectric detector and the second photoelectric detector to obtain a polarization output variable quantity, and the second differentiator is used for differentiating detection signals output by the third photoelectric detector and the fourth photoelectric detector to obtain an output result of differential polarization detection; and the third differentiator is used for differentiating output results of differential polarization detection output by the first differentiator and the second differentiator so as to remove polarization common-mode noise. According to the technical scheme, the technical problem that in the prior art, a laser or a detection light path device generates polarization noise due to temperature or stress, and consequently the performance of a quantum sensor is greatly affected is solved.

Description

Technical Field

[0001] The present invention relates to the field of quantum sensing technology, and in particular to a method and system for depolarizing common mode noise of a quantum sensor. Background Art

[0002] Quantum sensors are becoming the mainstream development direction in the field of weak or extremely weak magnetic field measurement and magnetic spectrum imaging due to their performance indicators that are much higher than those of traditional sensors. At present, quantum sensors mainly obtain the magnetic field to be measured by differential polarization detection of the Faraday rotation effect of alkali metals under the combined action of laser and magnetic field. The differential polarization detection method has the advantages of simple structure, easy integration, and its components can be produced and assembled without magnetization. However, in the application, there is also the problem of polarization noise generated by laser or detection optical path components due to temperature or stress, which greatly affects the performance of quantum sensors. Summary of the invention

[0003] The present invention provides a method and system for depolarizing common mode noise of a quantum sensor, which can solve the technical problem in the prior art that polarization noise is generated by lasers or detection optical path components due to temperature or stress, resulting in a significant impact on the performance of quantum sensors.

[0004] According to one aspect of the present invention, a method for depolarizing common mode noise of a quantum sensor is provided, and the method for depolarizing common mode noise of a quantum sensor comprises: step 1, setting a driving light source, a circular polarizer, an atomic gas chamber, a detection light source, a first polarization beam splitter, a beam splitter, a first photodetector, a second photodetector, a first differentiator, a second polarization beam splitter, a third photodetector, a fourth photodetector, a second differentiator, a third differentiator and a controller; step 2, driving light emitted by the driving light source enters the atomic gas chamber after passing through the circular polarizer to drive the alkali metal in the atomic gas chamber; laser light emitted by the detection light source is divided into a first polarized light and a second polarized light after passing through the first polarization beam splitter, the first polarized light enters the first photodetector, the second polarized light is divided into a first detection light and a second detection light after passing through the beam splitter, and the first detection light enters the second photodetector, The second detection light enters the atomic gas chamber, and the second detection light emitted from the atomic gas chamber is divided into a third polarized light and a fourth polarized light after passing through a second polarization splitter prism. The third polarized light enters a third photodetector, and the fourth polarized light enters a fourth photodetector. The first differentiator is used to differentiate the detection signal output by the first photodetector and the detection signal output by the second photodetector to obtain a polarization output change. The second differentiator is used to differentiate the detection signal output by the third photodetector and the detection signal output by the fourth photodetector to obtain an output result of differential polarization detection. The third differentiator is used to differentiate the polarization output change output by the first differentiator and the output result of differential polarization detection output by the second differentiator to remove polarization common mode noise. The controller calculates and obtains the measurement angular velocity without polarization common mode noise according to the signal output by the third differentiator.

[0005] According to another aspect of the present invention, a quantum sensor depolarization common mode noise system is provided. The quantum sensor depolarization common mode noise system uses the quantum sensor depolarization common mode noise method as described above to remove polarization common mode noise.

[0006] Furthermore, the quantum sensor depolarization common mode noise system includes a driving light source, a circular polarizer, an atomic gas chamber, a detection light source, a first polarization beam splitter, a beam splitter, a first photodetector, a second photodetector, a first differentiator, a second polarization beam splitter, a third photodetector, a fourth photodetector, a second differentiator, a third differentiator and a controller. The driving light emitted by the driving light source enters the atomic gas chamber after passing through the circular polarizer to drive the alkali metal in the atomic gas chamber; the laser emitted by the detection light source is divided into a first polarization light and a second polarization light after passing through the first polarization beam splitter, the first polarization light enters the first photodetector, the second polarization light is divided into a first detection light and a second detection light after passing through the beam splitter, the first detection light enters the second photodetector, the second detection light enters the atomic gas chamber, and the alkali metal in the atomic gas chamber is output. The emitted second detection light is divided into a third polarized light and a fourth polarized light after passing through a second polarization splitter prism. The third polarized light enters a third photodetector, and the fourth polarized light enters a fourth photodetector. The first differentiator is used to differentiate the detection signal output by the first photodetector and the detection signal output by the second photodetector to obtain a polarization output change. The second differentiator is used to differentiate the detection signal output by the third photodetector and the detection signal output by the fourth photodetector to obtain an output result of differential polarization detection. The third differentiator is used to differentiate the polarization output change output by the first differentiator and the output result of differential polarization detection output by the second differentiator to remove polarization common mode noise. The controller calculates and obtains the measurement angular velocity without polarization common mode noise according to the signal output by the third differentiator.

[0007] By applying the technical solution of the present invention, a method for depolarizing common mode noise of a quantum sensor is provided, which can effectively reduce the influence of polarization noise generated by the detection laser itself or by temperature and stress on the sensing noise of the quantum sensor; by adding a polarization beam splitter, a beam splitter, a first photodetector, a second photodetector and a first differentiator before the detection laser enters the gas chamber, the polarization state of the laser entering the gas chamber is measured, and the signal obtained by the final detection is differentiated to remove the polarization noise caused by the detection laser itself or by optical polarization components caused by temperature and stress. The above means are used to achieve the goal of removing common mode noise caused by polarization in quantum sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0009] Figure 1A schematic structural diagram of a quantum sensor depolarization common mode noise system provided according to a specific embodiment of the present invention is shown.

[0010] The above drawings include the following reference numerals:

[0011] 10. Driving light source; 20. Circular polarizer; 30. Atomic gas chamber; 40. Detection light source; 50. First polarization beam splitter prism; 60. Spectral prism; 70. First photodetector; 80. Second photodetector; 90. First differentiator; 100. Second polarization beam splitter prism; 110. Third photodetector; 120. Fourth photodetector; 130. Second differentiator; 140. Third differentiator; 150. Controller; 160. Three-dimensional coil. DETAILED DESCRIPTION

[0012] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0013] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0014] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0015] like Figure 1 As shown, according to a specific embodiment of the present invention, a quantum sensor depolarization common mode noise method is provided, and the quantum sensor depolarization common mode noise method includes: step one, setting a driving light source 10, a circular polarizer 20, an atomic gas chamber 30, a detection light source 40, a first polarization beam splitter 50, a beam splitter 60, a first photodetector 70, a second photodetector 80, a first differentiator 90, a second polarization beam splitter 100, a third photodetector 110, a fourth photodetector 120, a second differentiator 130, a third differentiator 140 and a controller 150; step two, the driving light emitted by the driving light source 10 enters the atomic gas chamber 30 after passing through the circular polarizer 20 to drive the alkali metal in the atomic gas chamber 30; the laser emitted by the detection light source 40 is divided into a first polarized light and a second polarized light after passing through the first polarization beam splitter 50, the first polarized light enters the first photodetector 70, the second polarized light is divided into a first detection light and a second detection light after passing through the beam splitter 60, and the first detection light enters the second The photodetector 80, the second detection light enters the atomic gas chamber 30, the second detection light emitted from the atomic gas chamber 30 is divided into a third polarized light and a fourth polarized light after passing through the second polarization splitter prism 100, the third polarized light enters the third photodetector 110, and the fourth polarized light enters the fourth photodetector 120, the first differentiator 90 is used to differentiate the detection signal output by the first photodetector 70 and the detection signal output by the second photodetector 80 to obtain the polarization output change, the second differentiator 130 is used to differentiate the detection signal output by the third photodetector 110 and the detection signal output by the fourth photodetector 120 to obtain the output result of the differential polarization detection, the third differentiator 140 is used to differentiate the polarization output change output by the first differentiator 90 and the output result of the differential polarization detection output by the second differentiator 130 to remove the polarization common mode noise, and the controller 150 calculates and obtains the measurement angular velocity without the polarization common mode noise according to the signal output by the third differentiator 140.

[0016] By using this configuration, a method for depolarizing common mode noise of quantum sensors is provided, which can effectively reduce the influence of polarization noise generated by the detection laser itself or by temperature and stress on the sensing noise of quantum sensors; by adding a polarization beam splitter, a beam splitter, a first photodetector, a second photodetector and a first differentiator before the detection laser enters the gas chamber, the polarization state of the laser entering the gas chamber is measured, and the signal obtained by the final detection is differentiated to remove the polarization noise caused by the detection laser itself or by optical polarization components caused by temperature and stress. The above means are used to achieve the goal of removing common mode noise caused by polarization in quantum sensors.

[0017] Compared with the previous differential detection optical path, this solution adds a polarization beam splitter and a beam splitter before the detection laser enters the atomic gas chamber, and uses the first photodetector D1 and the second photodetector D2 to collect the detection laser power reflected by the polarization beam splitter and the beam splitter. Assuming that the change in the polarization state of the laser caused by the detection laser light source or the polarization device is Φ, the output voltage of the photodetector D1 changes by Δs due to the change in the polarization state, and the output voltage of the photodetector D2 also changes by -Δs at the same time. The difference between the outputs of D1 and D2 can obtain the measurement noise 2Δs caused by the polarization noise. The polarization output change is differentiated from the output result of the differential polarization detection before finally inputting into the controller, and the result after removing the polarization common mode noise is output to the controller.

[0018] According to another aspect of the present invention, a quantum sensor depolarization common mode noise system is provided. The quantum sensor depolarization common mode noise system uses the quantum sensor depolarization common mode noise method as described above to remove polarization common mode noise.

[0019] By using this configuration, a quantum sensor depolarization common mode noise system is provided, which can effectively reduce the influence of the polarization noise generated by the detection laser itself or by temperature and stress on the sensing noise of the quantum sensor; by adding a polarization beam splitter, a beam splitter, a first photodetector, a second photodetector and a first differentiator before the detection laser enters the gas chamber, the polarization state of the laser entering the gas chamber is measured, and the signal obtained by the final detection is differentiated to remove the polarization noise caused by the detection laser itself or by the optical polarization components caused by temperature and stress. The above means are used to achieve the goal of removing the common mode noise caused by polarization in the quantum sensor.

[0020] Specifically, in the present invention, the quantum sensor depolarization common mode noise system includes a driving light source 10, a circular polarizer 20, an atomic gas chamber 30, a detection light source 40, a first polarization beam splitter 50, a beam splitter 60, a first photodetector 70, a second photodetector 80, a first differentiator 90, a second polarization beam splitter 100, a third photodetector 110, a fourth photodetector 120, a second differentiator 130, a third differentiator 140 and a controller 150. The driving light emitted by the driving light source 10 enters the atomic gas chamber 30 after passing through the circular polarizer 20 to drive the alkali metal in the atomic gas chamber 30; the laser emitted by the detection light source 40 is divided into a first polarized light and a second polarized light after passing through the first polarization beam splitter 50, the first polarized light enters the first photodetector 70, the second polarized light is divided into a first detection light and a second detection light after passing through the beam splitter 60, the first detection light enters the second photodetector 80, and the second detection light enters the atomic gas chamber 30. Chamber 30, the second detection light emitted from the atomic gas chamber 30 is divided into a third polarized light and a fourth polarized light after passing through the second polarization splitter prism 100, the third polarized light enters the third photodetector 110, and the fourth polarized light enters the fourth photodetector 120, the first differentiator 90 is used to differentiate the detection signal output by the first photodetector 70 and the detection signal output by the second photodetector 80 to obtain a polarization output change, the second differentiator 130 is used to differentiate the detection signal output by the third photodetector 110 and the detection signal output by the fourth photodetector 120 to obtain an output result of differential polarization detection, the third differentiator 140 is used to differentiate the polarization output change output by the first differentiator 90 and the output result of differential polarization detection output by the second differentiator 130 to remove polarization common mode noise, and the controller 150 calculates and obtains the measurement angular velocity without polarization common mode noise according to the signal output by the third differentiator 140.

[0021] In order to further understand the present invention, the following Figure 1 The method for depolarizing common-mode noise of a quantum sensor provided by the present invention is described in detail.

[0022] like Figure 1 As shown, according to a specific embodiment of the present invention, a method for removing polarization common mode noise of a quantum sensor is provided, by adding an optical component before the detection laser enters the gas chamber, measuring the polarization state of the laser entering the gas chamber, and performing a differential with the final detected signal, thereby removing the polarization noise caused by the detection laser itself or the optical polarization component caused by temperature and stress. The above means are used to achieve the goal of removing the common mode noise caused by polarization in the quantum sensor.

[0023] Specifically, the quantum sensor depolarization common mode noise method includes: step 1, setting a driving light source 10, a circular polarizer 20, an atomic gas chamber 30, a detection light source 40, a first polarization beam splitter 50, a beam splitter 60, a first photodetector 70, a second photodetector 80, a first differentiator 90, a second polarization beam splitter 100, a third photodetector 110, a fourth photodetector 120, a second differentiator 130, a third differentiator 140 and a controller 150; step 2, the driving light emitted by the driving light source 10 enters the atomic gas chamber 30 after passing through the circular polarizer 20 to drive the alkali metal in the atomic gas chamber 30; the laser emitted by the detection light source 40 is divided into a first polarized light and a second polarized light after passing through the first polarization beam splitter 50, the first polarized light enters the first photodetector 70, the second polarized light is divided into a first detection light and a second detection light after passing through the beam splitter 60, the first detection light enters the second photodetector 80, and the second detection light enters The atomic gas chamber 30, the second detection light emitted from the atomic gas chamber 30 is divided into a third polarized light and a fourth polarized light after passing through the second polarization splitter prism 100, the third polarized light enters the third photodetector 110, and the fourth polarized light enters the fourth photodetector 120, the first differentiator 90 is used to differentiate the detection signal output by the first photodetector 70 and the detection signal output by the second photodetector 80 to obtain a polarization output change, the second differentiator 130 is used to differentiate the detection signal output by the third photodetector 110 and the detection signal output by the fourth photodetector 120 to obtain an output result of differential polarization detection, the third differentiator 140 is used to differentiate the polarization output change output by the first differentiator 90 and the output result of differential polarization detection output by the second differentiator 130 to remove polarization common mode noise, and the controller 150 calculates and obtains the measurement angular velocity without polarization common mode noise according to the signal output by the third differentiator 140.

[0024] Compared with the previous differential detection optical path, this solution adds a polarization beam splitter and a beam splitter before the detection laser enters the atomic gas chamber, and uses photodetectors D1 and D2 to collect the detection laser power reflected by the polarization beam splitter and the beam splitter. Assuming that the change in the polarization state of the laser caused by the detection laser light source or polarization device is Φ, the output voltage of the photodetector D1 changes by Δs due to the change in polarization state, and the output voltage of the photodetector D2 also changes by -Δs (because the change in polarization state caused by temperature or stress will change the incident light of input D1 and D2), then the difference between the outputs of D1 and D2 can obtain the measurement noise 2Δs caused by polarization noise, and the polarization output change is differentiated from the output result of differential polarization detection before finally inputting the controller, and the result after removing the polarization common mode noise is output to the controller.

[0025] In summary, the present invention provides a method for depolarizing common mode noise of a quantum sensor, which can effectively avoid or circumvent polarization noise and effectively reduce the influence of polarization noise on measurement noise.

[0026] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0027] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for depolarizing common mode noise of a quantum sensor, characterized in that: The quantum sensor depolarization common mode noise method comprises: Step 1, setting a driving light source (10), a circular polarizer (20), an atomic gas chamber (30), a detection light source (40), a first polarization beam splitter prism (50), a beam splitter prism (60), a first photodetector (70), a second photodetector (80), a first differentiator (90), a second polarization beam splitter prism (100), a third photodetector (110), a fourth photodetector (120), a second differentiator (130), a third differentiator (140) and a controller (150); Step 2: the driving light emitted by the driving light source (10) enters the atomic gas chamber (30) after passing through the circular polarizer (20) to drive the alkali metal in the atomic gas chamber (30); the laser emitted by the detection light source (40) is divided into a first polarized light and a second polarized light after passing through the first polarization beam splitter prism (50), the first polarized light enters the first photodetector (70), the second polarized light is divided into a first detection light and a second detection light after passing through the beam splitter prism (60), the first detection light enters the second photodetector (80), the second detection light enters the atomic gas chamber (30), the second detection light emitted from the atomic gas chamber (30) is divided into a third polarized light and a fourth polarized light after passing through the second polarization beam splitter prism (100), the third polarized light enters the third photodetector (110), the fourth polarized light enters the fourth photodetector (12 0), the first differentiator (90) is used to differentiate the detection signal output by the first photodetector (70) and the detection signal output by the second photodetector (80) to obtain a polarization output change, the second differentiator (130) is used to differentiate the detection signal output by the third photodetector (110) and the detection signal output by the fourth photodetector (120) to obtain an output result of differential polarization detection, the third differentiator (140) is used to differentiate the polarization output change output by the first differentiator (90) and the output result of differential polarization detection output by the second differentiator (130) to remove polarization common mode noise, and the controller (150) calculates and obtains the measurement angular velocity without polarization common mode noise according to the signal output by the third differentiator (140).

2. A quantum sensor depolarization common mode noise system, characterized in that: The quantum sensor depolarization common mode noise system uses the quantum sensor depolarization common mode noise method as described in claim 1 to remove polarization common mode noise.

3. The quantum sensor depolarization common mode noise system according to claim 2, characterized in that: The quantum sensor depolarization common mode noise system comprises a driving light source (10), a circular polarizer (20), an atomic gas chamber (30), a detection light source (40), a first polarization beam splitter prism (50), a beam splitter prism (60), a first photodetector (70), a second photodetector (80), a first differentiator (90), a second polarization beam splitter prism (100), a third photodetector (110), a fourth photodetector (120), a second differentiator (130), a third differentiator (140) and a controller (150). The driving light emitted by the driving light source (10) passes through the circular polarizer (20) and enters the atomic gas chamber (30) to drive the alkali metal in the atomic gas chamber (30); the laser emitted by the detection light source (40) passes through the first polarization beam splitter (50) and is divided into a first polarized light and a second polarized light, the first polarized light enters the first photodetector (70), the second polarized light passes through the beam splitter (60) and is divided into a first detection light and a second detection light, the first detection light enters the second photodetector (80), and the second detection light enters the atomic gas chamber (3 0), the second detection light emitted from the atomic gas chamber (30) is divided into a third polarized light and a fourth polarized light after passing through a second polarization beam splitter prism (100), the third polarized light enters the third photodetector (110), and the fourth polarized light enters the fourth photodetector (120), the first differentiator (90) is used to differentiate the detection signal output by the first photodetector (70) and the detection signal output by the second photodetector (80) to obtain a polarization output variation, the second differentiator (130) is used to differentiate the detection signal output by the third photodetector (110) and the detection signal output by the fourth photodetector (120) to obtain an output result of differential polarization detection, the third differentiator (140) is used to differentiate the polarization output variation output by the first differentiator (90) and the output result of differential polarization detection output by the second differentiator (130) to remove polarization common mode noise, and the controller (150) calculates and obtains the measurement angular velocity without polarization common mode noise according to the signal output by the third differentiator (140).

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