CN113514046B - Atomic spin precession signal detection device and method based on Mach-Zehnder interference - Google Patents
Atomic spin precession signal detection device and method based on Mach-Zehnder interference Download PDFInfo
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Abstract
According to the atomic spin precession signal detection device and method based on Mach-Zehnder interference, laser modulated by electro-optic phases is used as an interference measurement light source, on one hand, the method belongs to a homodyne detection principle, and system errors caused by frequency drift of the laser light source are avoided; on the other hand, based on the Mach-Zehnder interferometry, atomic spin precession signal information is obtained by measuring the phase difference between two arms of the interferometer, and is irrelevant to the detection optical power, so that system errors caused by power drift of a laser light source are avoided, meanwhile, the low-frequency noise fluctuation such as 1/f can be effectively restrained by utilizing an electro-optical modulation detection mode, and the long-term stability of an atomic spin inertia measurement system is favorably improved.
Description
Technical Field
The invention relates to an atomic spin precession signal detection technology, in particular to an atomic spin precession signal detection device and method based on Mach-Zehnder interference. The method can be used for accurately measuring the atom spin precession signal in instrument equipment such as an atom magnetometer, an atom gyroscope and the like.
Background
Spin-exchange relaxation (SERF) free atomic spin inertial measurement becomes one of important development directions in the field of future inertial measurement by virtue of the advantages of ultrahigh sensitivity and ultrahigh precision. The polarized atomic spin sensitive carrier rotates inertially and produces a precession which can interact with linearly polarized light and produce a rotation effect. Therefore, the detection of the atomic spin precession signal can be expressed as the optical rotation angle detection of linearly polarized light after passing through the alkali metal gas chamber. Generally, for a high-precision SERF atomic spin inertial measurement system, the generated optical rotation angle is in the micro radian order, and the system belongs to weak signal detection, so that a high-precision atomic spin precession signal detection technology is one of key technologies for realizing high-precision SERF atomic spin inertial measurement.
Conventional atomic spin precession signal detection methods such as: the methods of Faraday modulator detection, photoelastic modulation detection, polarization balance difference detection and the like are all to measure polarization information by detecting the change of optical power by using the Malus law to obtain the optical rotation angle. The biggest disadvantage of the scheme for detecting weak signals by using laser polarization information is that the polarization information cannot be directly obtained, but is detected by converting the polarization information into optical power, so that the fluctuation of the detected optical power is coupled with the polarization information, and the stability of the detected optical power greatly limits the detection precision. Although the stable control of the detection light power can be realized by using a closed-loop control technology, the control precision is still influenced by the noise of a laser light source, the ambient temperature and the like, and the requirement of a high-precision SERF atomic spin inertial measurement system cannot be met.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the atomic spin precession signal detection device and method based on Mach-Zehnder interference overcome the defects of the prior art, and utilize laser modulated by an electro-optic phase as an interference measurement light source, on one hand, the method belongs to a homodyne detection principle, and avoids system errors caused by frequency drift of the laser light source; on the other hand, based on the Mach-Zehnder interferometry, atomic spin precession signal information is obtained by measuring the phase difference between two arms of the interferometer, and is irrelevant to the detection optical power, so that system errors caused by power drift of a laser light source are avoided, meanwhile, the low-frequency noise fluctuation such as 1/f can be effectively restrained by utilizing an electro-optical modulation detection mode, and the long-term stability of an atomic spin inertia measurement system is favorably improved.
The technical solution of the invention is as follows:
an atomic spin precession signal detection device based on Mach-Zehnder interference, comprising:
the electro-optical modulator is used for modulating the detection laser at high frequency to improve the detection sensitivity of weak signals;
the polarization beam splitter prism is used for splitting a light source into two beams of laser with the same optical characteristics, wherein one beam of laser is used as signal light to form a first optical path in the Mach-Zehnder interference optical paths, and the other beam of laser is used as reference light to form a second optical path in the Mach-Zehnder interference optical paths;
the atomic gas chamber is positioned on the first light path, is arranged between the depolarization beam splitter prism and the polarization beam splitter prism, and is used for enabling the signal light to form a phase difference;
the depolarization beam splitter prism is used for enabling the first optical path and the second optical path to be superposed on the photosensitive surface of the first optical path and the second optical path to form two paths of Mach-Zehnder interference light;
and the phase-locked amplifier is used for demodulating the phase difference of the signal light through the signal input of the two paths of Mach-Zehnder interference light so as to extract the optical rotation angle information through the phase difference and further realize the atomic spin precession signal detection.
The two paths of Mach-Zehnder interference light comprise a first path of Mach-Zehnder interference light formed by the transmission signal light of the first optical path and the reflection reference light of the second optical path on one side of the photosensitive surface, and a second path of Mach-Zehnder interference light formed by the transmission reference light of the second optical path and the reflection signal light of the first optical path on the other side of the photosensitive surface.
The first path of Mach-Zehnder interference light sequentially passes through the 1/4 wave plate and the second analyzer and then is input into the second photoelectric detector, and the second photoelectric detector is connected with the phase-locked amplifier.
And the second path of Mach-Zehnder interference light passes through the first analyzer and then is input into the first photoelectric detector, and the first photoelectric detector is connected with the phase-locked amplifier.
The electro-optic modulator is connected to a driver.
The electro-optical modulator is connected with the detection laser through a 1/2 wave plate.
And a second reflecting mirror is arranged on a second light path between the polarization beam splitter prism and the depolarization beam splitter prism.
And a first reflector is arranged on a first light path between the atomic gas chamber and the depolarizing beam splitter prism, and the atomic gas chamber is positioned in a magnetic shielding system.
The atomic spin precession signal detection method based on Mach-Zehnder interference is characterized by comprising the following steps of:
step 1, utilizing an electro-optical modulator to perform phase modulation on detection laser and form a Mach-Zehnder interferometric light source;
step 2, dividing the Mach-Zehnder interference measurement light source into two beams of laser with the same optical characteristics by using a polarization beam splitter prism, wherein one beam of laser is used as signal light to form a first optical path in the Mach-Zehnder interference optical paths, and the other beam of laser is used as reference light to form a second optical path in the Mach-Zehnder interference optical paths;
step 4, enabling the first optical path and the second optical path to be superposed on the photosensitive surfaces of the first optical path and the second optical path by using a depolarizing beam splitter prism and forming two paths of Mach-Zehnder interference light;
and 5, demodulating to obtain the phase difference of the signal light by utilizing a phase-locked amplifier through the signal input of the two paths of Mach-Zehnder interference light so as to extract the optical rotation angle information through the phase difference and further realize the atomic spin precession signal detection. The two paths of Mach-Zehnder interference light comprise a first path of Mach-Zehnder interference light formed by the transmission signal light of the first optical path and the reflection reference light of the second optical path on one side of the photosensitive surface, and a second path of Mach-Zehnder interference light formed by the transmission reference light of the second optical path and the reflection signal light of the first optical path on the other side of the photosensitive surface.
The relationship between the optical rotation angle and the phase difference is as follows:
where θ is the angle of rotation formed by precession of atomic spins, and C = tan β 1 ,D＝tanβ 2 ,E＝tanφ,F＝ tan(φ BS /2)，β 1 Is the included angle between the transmission axis of the second analyzer and the x axis of the first path of Mach-Zehnder interference light, beta 2 Is the included angle between the transmission axis of the first analyzer and the x axis of the second path of Mach-Zehnder interference light, phi is the phase difference formed by the atomic gas chamber by the signal light, and phi is the phase difference formed by the atomic gas chamber BS Is a constant, phi = delta phi + (pi/2) - (phi) BS And/2), the delta psi is the phase difference between the first path of Mach-Zehnder interference light and the second path of Mach-Zehnder interference light directly obtained by the phase-locked amplifier.
The invention has the following technical effects: the invention provides an atomic spin precession signal detection device and method based on Mach-Zehnder interference, which overcome the defect that the stability of an output signal of the traditional atomic spin precession signal detection methods such as photoelastic modulation detection and polarization balance differential detection is easy to be fluctuated by the power of detection light. The device uses laser modulated by an electro-optic phase as an interference measurement light source, on one hand, the method belongs to a homodyne detection principle, and system errors caused by frequency drift of the laser light source are avoided; on the other hand, the method is based on a Mach-Zehnder interferometry technology, atomic spin precession signal information is obtained by measuring the phase difference between two arms of an interferometer, and the atomic spin precession signal information is irrelevant to the detection optical power, so that the system error caused by the power drift of a laser light source is avoided. Meanwhile, the detection method utilizes an electro-optical modulation detection mode, can effectively inhibit low-frequency noise fluctuation such as 1/f and the like, and is favorable for improving the long-term stability of the atomic spin inertia measurement system.
Compared with the prior art, the invention has the advantages that: on the one hand, the method obtains the atomic spin precession signal by measuring the phase difference and is irrelevant to the information such as the optical power, the frequency and the like of the detected light, thereby avoiding the fluctuation error caused by the performance of the detected laser; on the other hand, the method belongs to a modulation detection method, can effectively inhibit the influence of low-frequency noise (f is frequency) such as 1/f, and is beneficial to improving the long-term stability of the atomic spin inertia measurement system.
Drawings
Fig. 1 is a schematic diagram showing the structure of an atomic spin precession signal detection apparatus according to the present invention.
FIG. 2 is a schematic flow chart of the atomic spin precession signal detection method based on Mach-Zehnder interference according to the present invention. Fig. 2 includes the following steps: step 1, detecting that laser output by a laser is subjected to phase modulation by EOM; step 2, the phase-modulated detection laser forms two optical paths, wherein the first optical path is signal light, the first optical path comprises a polarized alkali metal gas chamber (or called an atomic gas chamber), and the second optical path is reference light; step 3, generating a phase difference phi by the two optical paths; step 4, adjusting the positions of the 1/4 wave plate and the transmission axis of the analyzer to maximize the phase difference and improve the detection sensitivity; step 5, inputting the two paths of output light intensity signals into a phase-locked amplifier for demodulation to obtain the phase difference; and 6, obtaining the optical rotation angle according to the relation between the phase difference and the optical rotation angle, and realizing the detection of the atomic spin precession signal.
The reference numbers are listed below: 1-detection laser; 2-1/2 wave plate; 3-Electro-Optic modulators (EOMs); 4-a driver; 5-polarizing beam splitter Prism (PBS); 6-magnetic shielding system; 7-atomic gas cell; 8-a first mirror; 9-a second mirror; 10-depolarizing beam splitter (NPBS, non-polarizing beamsplitters; or abbreviated as BS); 11-a first analyzer; 12-a first photodetector; 13-1/4 wave plate; 14-a second analyzer; 15-a second photodetector; XYZ-coordinate axis.
Detailed Description
The invention is explained below with reference to the figures (fig. 1-2) and examples.
Fig. 1 is a schematic diagram showing the structure of an atomic spin precession signal detection apparatus according to the present invention. FIG. 2 is a schematic flow chart of the atomic spin precession signal detection method based on Mach-Zehnder interference according to the present invention. Referring to fig. 1 to 2, an atomic spin precession signal detection apparatus based on mach-zehnder interference includes: the electro-optical modulator 3 is used for modulating the detection laser at high frequency, improving the detection sensitivity of weak signals and serving as a Mach-Zehnder interference measurement light source; a polarization beam splitter prism 5 for splitting the mach-zehnder interference measurement light source into two beams of laser light with the same optical characteristics, wherein one beam of laser light is used as signal light to form a first optical path in the mach-zehnder interference optical path, and the other beam of laser light is used as reference light to form a second optical path in the mach-zehnder interference optical path; the atomic gas chamber 7 is positioned on the first light path, is arranged between the depolarization beam splitter prism 10 and the polarization beam splitter prism 5, and is used for enabling the signal light to form a phase difference; the depolarization beam splitter prism 10 is used for enabling the first optical path and the second optical path to be superposed on the photosensitive surface of the first optical path and the second optical path to form two paths of Mach-Zehnder interference light; and the phase-locked amplifier is used for demodulating the phase difference of the signal light through the signal input of the two paths of Mach-Zehnder interference light so as to extract the optical rotation angle information through the phase difference and further realize the atomic spin precession signal detection.
The two paths of Mach-Zehnder interference light comprise a first path of Mach-Zehnder interference light formed by the transmission signal light of the first optical path and the reflection reference light of the second optical path on one side of the photosensitive surface, and a second path of Mach-Zehnder interference light formed by the transmission reference light of the second optical path and the reflection signal light of the first optical path on the other side of the photosensitive surface. The first path of Mach-Zehnder interference light sequentially passes through the 1/4 wave plate 13 and the second analyzer 14 and then is input into the second photoelectric detector 15, and the second photoelectric detector 15 is connected with the phase-locked amplifier. The second path of mach-zehnder interference light passes through the first analyzer 11 and then is input into the first photoelectric detector 12, and the first photoelectric detector 12 is connected with the phase-locked amplifier. The electro-optical modulator 3 is connected to a driver 4. The electro-optical modulator 3 is connected with the detection laser 1 through the 1/2 wave plate 2. And a second reflecting mirror 9 is arranged on a second light path between the polarization beam splitter prism 5 and the depolarization beam splitter prism 10. A first reflector 8 is arranged on a first light path between the atomic gas chamber 7 and the depolarization beam splitter prism 10, and the atomic gas chamber 7 is located in the magnetic shielding system 6.
The atomic spin precession signal detection method based on Mach-Zehnder interference comprises the following steps: step 1, modulating detection laser into a Mach-Zehnder interference measurement light source by using an electro-optical modulator; step 2, dividing the Mach-Zehnder interference measurement light source into two beams of laser with the same optical characteristics by using a polarization beam splitter prism, wherein one beam of laser is used as signal light to form a first optical path in a Mach-Zehnder interference optical path, and the other beam of laser is used as reference light to form a second optical path in the Mach-Zehnder interference optical path; step 3, forming a phase difference of the signal light by utilizing an atomic gas chamber between a depolarization beam splitter prism and the polarization beam splitter prism; step 4, enabling the first optical path and the second optical path to be superposed on the photosensitive surfaces of the first optical path and the second optical path by using a depolarizing beam splitter prism and forming two paths of Mach-Zehnder interference light; and 5, demodulating to obtain the phase difference of the signal light by utilizing a phase-locked amplifier through signal input of the two paths of Mach-Zehnder interference light so as to extract optical rotation angle information through the phase difference and further realize atomic spin precession signal detection, wherein the two paths of Mach-Zehnder interference light comprise a first path of Mach-Zehnder interference light formed by the transmission signal light of the first optical path and the reflection reference light of the second optical path on one side of the photosensitive surface and a second path of Mach-Zehnder interference light formed by the transmission reference light of the second optical path and the reflection signal light of the first optical path on the other side of the photosensitive surface.
The relation between the optical rotation angle and the phase difference is as follows:
wherein θ is originalAngle of rotation formed by precession of the spin of a photon, C = tan β 1 ,D＝tanβ 2 ,E＝tanφ,F＝ tan(φ BS /2)，β 1 Is the included angle between the transmission axis of the second analyzer and the x axis of the first path of Mach-Zehnder interference light, beta 2 Is the included angle between the transmission axis of the first analyzer and the x axis of the second path of Mach-Zehnder interference light, phi is the phase difference formed by the atomic gas chamber by the signal light, and phi is the phase difference formed by the atomic gas chamber BS Is a constant, phi = delta psi + (pi/2) - (phi) BS And/2), the delta psi is the phase difference between the first path of Mach-Zehnder interference light and the second path of Mach-Zehnder interference light directly obtained by the phase-locked amplifier.
The atomic spin precession signal detection device and method based on Mach-Zehnder interference utilize a Mach-Zehnder interference measurement technology to obtain an atomic spin precession signal by measuring a phase difference between two output light beams, and effectively avoid the defect that the detection precision of the atomic spin precession signal is improved due to the limitation of detection light power and frequency fluctuation. The method takes detection laser modulated by an electro-optic phase modulator as an interference measurement light source, divides the laser into two beams of laser with the same optical property by utilizing a polarization beam splitter prism to form a Mach-Zehnder interference light path, places a polarized alkali metal gas chamber in one light path of an interferometer to form a phase difference, finally, the two light paths are superposed on a photosensitive surface of a depolarization prism to form interference, and finally, a phase difference is obtained by utilizing a phase-locked amplifier for demodulation, so that high-precision atomic spin precession signal detection is realized. On the basis of the Mach-Zehnder interference principle, on one hand, the atomic spin precession signal is obtained by measuring the phase difference and is irrelevant to information such as optical power, frequency and the like of detection light, so that fluctuation errors caused by the performance of a detection laser are avoided; on the other hand, the method belongs to a modulation detection method, can effectively inhibit the influence of low-frequency noise such as 1/f and the like, and is beneficial to improving the long-term stability of the atomic spin inertia measurement system.
An atomic spin precession signal detection device and method based on Mach-Zehnder interference are characterized in that: the device comprises a detection laser 1, a 1/2 wave plate 2, an electro-optical modulator (EOM) 3, a driver 4 a Polarization Beam Splitter (PBS) 5, a magnetic shielding system 6, an atomic gas chamber 7, a first reflector 8, a second reflector 9,A depolarization beam splitter prism (BS) 10, a first analyzer 11, a first photodetector 12, a 1/4 wave plate 13, a second analyzer 14, a second photodetector 15 and a lock-in amplifier. Wherein, the laser emitted by the detection laser 1 passes through the 1/2 wave plate 2 to adjust the polarization direction of the laser and then enters the electro-optical modulator 3, one angular frequency is omega, and the amplitude is phi 0 Is connected to the external sinusoidal voltage signal phi (t) = phi 0 sin ω t, t is time, and is applied to the electro-optical modulator 3 through the driver 4 to realize phase modulation of the detection laser, and is divided into two paths of transmission light (p light) and reflection light (s light) by the polarization beam splitter prism 5 to propagate. The p light as signal light sequentially passes through an atomic gas chamber 7 and a first reflector 8 in a magnetic shielding system 6 to reach a depolarization beam splitter prism 10; the other s-beam is also passed through a second mirror 9 as reference beam to a depolarizing Beam Splitter (BS) 10. The optical path is a typical Mach-Zehnder interference optical path, and transmitted s light and reflected p light meet and are superposed on a photosensitive surface of the depolarizing beam splitter prism 10 and then reach a first photoelectric detector 12 through a first analyzer 11; meanwhile, the other path of transmitted p light and the reflected s light are superposed on the photosensitive surface of the depolarizing beam-splitting prism 10 and then reach the second photodetector 15 through the 1/4 wave plate 13 and the second analyzer 14. The output light intensity signals of the two photoelectric detectors are input into a phase-locked amplifier for phase analysis, the phase difference can be finally obtained, and the detection of the atomic spin precession signal can be realized by measuring the phase difference.
The 1/2 wave plate 2 is parallel to the optical axis of an electro-optical modulator (EOM) 3 and forms an angle of 45 degrees with the x axis; the first reflector 8 and the second reflector 9 form an angle of 45 degrees with the propagation direction of the laser, so that the laser is reflected vertically; the optical axis of a depolarization beam splitter prism (BS) 10 forms an angle of 45 degrees with the x axis; the optical axis of the 1/4 wave plate 13 is parallel to the x axis, namely the optical axis still is linearly polarized after passing through the 1/4 wave plate; the transmission axes of the first analyzer 11 and the second analyzer 14 should be selected to have an appropriate angle so that the phase difference of the final output of the lock-in amplifier reaches a maximum value.
The electro-optical modulator (EOM) 3 may be a spatial type device, and an optical fiber type device may be used to reduce the volume of the detection system. If a fiber type EOM is used, the laser source should also be pigtailed output laser.
If the optical fiber type EOM is used for the experiment, the polarization splitting prism 5 can be replaced by an optical fiber beam splitter with a tail fiber as a polarization maintaining optical fiber, and the optical fiber path can be adjusted to remove the first reflecting mirror 8 and the second reflecting mirror 9, so as to further reduce the volume of the detection system.
The sine voltage signal is input to the driver 4 to realize the phase modulation function of the electro-optical modulator, so that the detection precision of the detection method can be optimized by changing the information such as the offset and the frequency of the modulation signal.
The principle of the invention is as follows: after the detuned linear polarization detection light passes through the polarized atomic gas chamber, the passing linear polarization light generates a light rotation phenomenon due to the circular birefringence of the atomic gas chamber, and the inertial rotation information of the carrier can be obtained by measuring the light rotation angle. The invention provides an atomic spin precession signal detection device and method based on Mach-Zehnder interference, which extract optical rotation angle information by measuring the phase difference of two laser beams after passing through an interferometer. The specific principle is as follows:
after the linearly polarized detection light passes through a 1/2 wave plate (the fast axis and the x axis form an angle of 45 °), the jones matrix of the laser can be expressed as:
the modulated signal is phi (t) = phi 0 The electro-optic modulator of sin ω t then becomes:
the modulated laser output by the EOM is divided into two beams of light after passing through the PBS, wherein the transmitted p light serves as signal light and passes through the atomic gas chamber, the reflected s light serves as reference light, and the two beams of light form a Mach-Zehnder interference light path and meet the light wave superposition interference on the photosensitive surface of the BS. After passing through the BS, the jones matrix after the transmitted signal light and the reflected reference light interfere is represented as:
the jones matrix after the other path of reflected signal light interferes with the transmitted reference light is expressed as:
in the formula, subscripts p and s denote p-polarized light and s-polarized light separated by the PBS, 1 and 2 denote the output of the BS, and θ is the angle of rotation formed by precession of atomic spins. Let d be the optical path difference between the two paths, phi BS Phi and phi Ma 、φ Mb Representing the phase difference between p-polarized and s-polarized light at the BS and the two mirrors, respectively.
Interference light E t Passing through a 1/4 wave plate (the fast axis is located on the x axis) and a first analyzer (the transmission axis is beta to the x axis) 1 Angle) to E' t And is formed by a first photodetector D t Probing, jones matrix is expressed as:
E′ t ＝E PAt (β 1 )·E Q (0°)·E t
first photodetector D t The detected light intensity is:
in the formula:
another path of interference light E r Passing through a second analyzer (the transmission axis is beta to the x-axis) 2 Angle) becomes E' r And by a second photodetector D r Detection, jones matrix is expressed as:
E′ r ＝E PAr (β 2 )·E r
second photodetector D r The detected light intensity is:
in the formula:
ψ r ＝kd+(φ Mb -φ Ma )+φ r
two paths of light intensity are input into a lock-in amplifier to carry out phase demodulation to obtain a phase difference delta psi (delta psi = psi) t -ψ r ) Let the final phase difference phi = delta phi + (pi/2) - (phi) BS And/2), the relation between the optical rotation angle and the phase difference is as follows:
in the formula: c = tan β 1 ,D＝tanβ 2 ,E＝tanφ,F＝tan(φ BS /2)
Therefore, the method based on the Mach-Zehnder interference realizes the detection of the atomic spin precession signal.
Fig. 1 is a block diagram of an atomic spin precession signal detection apparatus according to the present invention, based on mach-zehnder interference. As can be seen from the figure, the atomic spin precession signal detection device based on Mach-Zehnder interference of the invention is composed of a detection laser 1, a 1/2 wave plate 2, an electro-optical modulator (EOM) 3, a driver 4, a polarization beam splitter Prism (PBS) 5, a magnetic shielding system 6, an atomic gas chamber 7, a first reflector 8, a second reflector 9, a depolarization beam splitter prism (BS) 10, a first analyzer 11, a first photoelectric detector 12, a 1/4 wave plate 13, a second analyzer 14, a second photoelectric detector 15 and a lock-in amplifier.
After the linearly polarized detection light passes through a 1/2 wave plate (the fast axis and the x axis form an angle of 45 °), the jones matrix of the laser can be expressed as:
the modulated signal is phi (t) = phi 0 The electro-optic modulator of sin ω t then becomes:
the modulated laser output by the EOM is divided into two beams of light after passing through the PBS, wherein the transmitted p light serves as signal light and passes through the atomic gas chamber, the reflected s light serves as reference light, and the two beams of light form a Mach-Zehnder interference light path and meet the light wave superposition interference on the photosensitive surface of the BS. After passing through the BS, the jones matrix after the transmitted signal light and the reflected reference light interfere is represented as:
the jones matrix after the other path of reflected signal light interferes with the transmitted reference light is expressed as:
in the formula, subscripts p and s denote p-polarized light and s-polarized light separated by the PBS, 1 and 2 denote the output of the BS, and θ is the angle of rotation formed by precession of atomic spins. Let d be the optical path difference between the two paths, phi BS Phi and phi Ma 、φ Mb Representing the phase difference between p-polarized and s-polarized light at the BS and the two mirrors, respectively.
Interference light E t Passing through a 1/4 wave plate (the fast axis is located on the x axis) and a first analyzer (the transmission axis is beta to the x axis) 1 Angle) to E' t And is formed by a first photodetector D t Probing, jones matrix is expressed as:
E′ t ＝E PAt (β 1 )·E Q (0°)·E t
first photodetector D t The detected light intensity is:
in the formula:
another path of interference light E r Passing through a second analyzer (the transmission axis is beta to the x-axis) 2 Angle) becomes E' r And by a second photodetector D r Detection, jones matrix is expressed as:
E′ r ＝E PAr (β 2 )·E r
second photodetector D r The detected light intensity is:
in the formula:
ψ r ＝kd+(φ Mb -φ Ma )+φ r
inputting the two light beams into a lock-in amplifier for phase demodulation to obtain a phase difference delta phi (delta phi = phi) t -ψ r ) Let the final phase difference phi = delta phi + (pi/2) - (phi) BS And/2), the relationship between the optical rotation angle and the phase difference is as follows:
in the formula: c = tan β 1 ,D＝tanβ 2 ,E＝tanφ,F＝tan(φ BS /2). Thereby realizing the detection of the atomic spin precession signal.
FIG. 2 is a flow chart of the atomic spin precession signal detection method based on Mach-Zehnder interference according to the present invention. As can be seen, the method first phase modulates the detection laser output laser input EOM, and the modulation signal is provided by a voltage signal applied to a driver. The modulated laser light is divided into two laser beams with the same optical characteristics through PBS to form a Mach-Zehnder interference light path. And (3) placing the polarized alkali metal gas chamber in one optical path of the Mach-Zehnder interferometer to be used as signal light, taking the other optical path as reference light, and finally forming interference on the photosensitive surface of the BS by the two optical paths, wherein the output interference light carries the phase difference generated by the atomic gas chamber. In order to improve the detection sensitivity of the atomic spin precession signal, two interfered detection light beams respectively pass through an analyzer with a proper azimuth angle and are detected by a photoelectric detector, the detection signals are input into a phase-locked amplifier for phase analysis to obtain the phase difference, and finally optical rotation angle information is obtained according to a relational expression of the phase difference and the optical rotation angle obtained by theoretical analysis, so that the high-precision atomic spin precession signal detection based on Mach-Zehnder interference is realized.
Those skilled in the art will appreciate that the invention may be practiced without these specific details. It is pointed out here that the above description is helpful for the person skilled in the art to understand the invention, but does not limit the scope of protection of the invention. Any and all equivalents, modifications, and/or omissions to the system described above may be made without departing from the spirit and scope of the invention.
Claims (8)
1. An atomic spin precession signal detection device based on Mach-Zehnder interference, comprising:
the electro-optical modulator is used for modulating the detection laser at high frequency to improve the detection sensitivity of weak signals;
the polarization beam splitter prism is used for splitting a light source into two beams of laser with the same optical characteristics, wherein one beam of laser is used as signal light to form a first optical path in the Mach-Zehnder interference optical paths, and the other beam of laser is used as reference light to form a second optical path in the Mach-Zehnder interference optical paths;
the atomic gas chamber is positioned on the first light path, is arranged between the depolarization beam splitter prism and the polarization beam splitter prism, and is used for enabling the signal light to form a phase difference;
the depolarization beam splitter prism is used for enabling the first optical path and the second optical path to be superposed on the photosensitive surface of the first optical path and the second optical path to form two paths of Mach-Zehnder interference light;
the phase-locked amplifier is used for demodulating the phase difference of the signal light through the signal input of the two paths of Mach-Zehnder interference light so as to extract the optical rotation angle information through the phase difference and further realize the atomic spin precession signal detection;
the two paths of Mach-Zehnder interference light comprise a first path of Mach-Zehnder interference light formed by the transmission signal light of the first optical path and the reflection reference light of the second optical path on one side of the photosensitive surface, and a second path of Mach-Zehnder interference light formed by the transmission reference light of the second optical path and the reflection signal light of the first optical path on the other side of the photosensitive surface.
2. The atomic spin precession signal detection device based on mach-zehnder interference according to claim 1, wherein the first path of mach-zehnder interference light sequentially passes through a 1/4 wave plate and a second analyzer and then is input to a second photoelectric detector, and the second photoelectric detector is connected to the lock-in amplifier.
3. The atomic spin precession signal detection device based on mach-zehnder interference according to claim 1, wherein the second path of mach-zehnder interference light is input to a first photoelectric detector after passing through a first analyzer, and the first photoelectric detector is connected to the lock-in amplifier.
4. The mach-zehnder interference based atomic spin precession signal detection device of claim 1, wherein the electro-optic modulator is connected to a driver.
5. The mach-zehnder interference based atomic spin precession signal detection device according to claim 1, wherein the electro-optic modulator is connected to the detection laser through a 1/2 wave plate.
6. The mach-zehnder interference based atomic spin precession signal detection device of claim 1, wherein a second mirror is disposed on a second optical path between the polarization splitting prism and the depolarizing splitting prism.
7. The mach-zehnder interference based atomic spin precession signal detection device according to claim 1, characterized in that a first mirror is arranged on a first light path between the atomic gas cell and the depolarizing beam splitter prism, and the atomic gas cell is located in a magnetic shielding system.
8. The atomic spin precession signal detection method based on Mach-Zehnder interference is characterized by comprising the following steps of:
step 1, modulating detection laser into a Mach-Zehnder interference measurement light source by using an electro-optical modulator;
step 2, dividing the Mach-Zehnder interference measurement light source into two beams of laser with the same optical characteristics by using a polarization beam splitter prism, wherein one beam of laser is used as signal light to form a first optical path in a Mach-Zehnder interference optical path, and the other beam of laser is used as reference light to form a second optical path in the Mach-Zehnder interference optical path;
step 3, utilizing an atomic air chamber between the depolarization beam splitter prism and the polarization beam splitter prism to enable the signal light to form a phase difference;
step 4, enabling the first optical path and the second optical path to be superposed on the photosensitive surfaces of the first optical path and the second optical path by using a depolarizing beam splitter prism and forming two paths of Mach-Zehnder interference light;
step 5, utilizing a lock-in amplifier to input and demodulate the two paths of Mach-Zehnder interference light signals to obtain a phase difference of the signal light, so as to extract optical rotation angle information through the phase difference and further realize atomic spin precession signal detection, wherein the two paths of Mach-Zehnder interference light include a first path of Mach-Zehnder interference light formed by the transmission signal light of the first optical path and the reflection reference light of the second optical path on one side of the photosensitive surface and a second path of Mach-Zehnder interference light formed by the transmission reference light of the second optical path and the reflection signal light of the first optical path on the other side of the photosensitive surface;
the relationship between the optical rotation angle and the phase difference is as follows:
where θ is the angle of rotation formed by precession of atomic spins, and C = tan β 1 ，D＝tanβ 2 ，E＝tanφ，F＝tan(φ BS /2)，β 1 Is the included angle between the transmission axis of the second analyzer and the x axis of the first path of Mach-Zehnder interference light, beta 2 Is the included angle between the transmission axis of the first analyzer and the x axis of the second path of Mach-Zehnder interference light, phi is the phase difference formed by the atomic gas chamber by the signal light, and phi is the phase difference formed by the atomic gas chamber BS Is a constant, phi = delta psi + (pi/2) - (phi) BS And/2), the delta psi is the phase difference between the first path of Mach-Zehnder interference light and the second path of Mach-Zehnder interference light directly obtained by the phase-locked amplifier.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104677508A (en) * | 2015-03-16 | 2015-06-03 | 北京航空航天大学 | Atomic spin precession detection method and device based on circular polarization detection light |
| CN106969845A (en) * | 2017-03-28 | 2017-07-21 | 南京理工大学 | The detection method and device of each light beam optical path difference of optical fibre matrix type point source generator |
| CN108008531A (en) * | 2017-11-30 | 2018-05-08 | 北京航空航天大学 | A kind of raman laser light path matching system based on Mach-Zehnder interferometer |
| CN109631959A (en) * | 2018-11-12 | 2019-04-16 | 北京航空航天大学 | A kind of atomic spin precession detection device signal anti-interference ability optimization method based on optical fiber Sagnac interference |
| AU2018349505A1 (en) * | 2017-10-10 | 2020-04-23 | Japan Aviation Electronics Industry, Limited | Mach-zehnder type atomic interferometric gyroscope |
| CN112269155A (en) * | 2020-10-20 | 2021-01-26 | 上海理工大学 | All-fiber magnetometer device |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4559650B2 (en) * | 2001-03-22 | 2010-10-13 | シチズンホールディングス株式会社 | Optical rotation measuring device and optical rotation measuring method |
| CN106017689B (en) * | 2016-07-11 | 2017-11-24 | 北京航空航天大学 | A kind of atomic spin precession differential polarization detection means based on acousto-optic modulation |
| JP6818332B1 (en) * | 2019-12-25 | 2021-01-20 | 日本航空電子工業株式会社 | Atomic gyroscope, atom interferometer |
-
2021
- 2021-07-08 CN CN202110773725.4A patent/CN113514046B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104677508A (en) * | 2015-03-16 | 2015-06-03 | 北京航空航天大学 | Atomic spin precession detection method and device based on circular polarization detection light |
| CN106969845A (en) * | 2017-03-28 | 2017-07-21 | 南京理工大学 | The detection method and device of each light beam optical path difference of optical fibre matrix type point source generator |
| AU2018349505A1 (en) * | 2017-10-10 | 2020-04-23 | Japan Aviation Electronics Industry, Limited | Mach-zehnder type atomic interferometric gyroscope |
| CN108008531A (en) * | 2017-11-30 | 2018-05-08 | 北京航空航天大学 | A kind of raman laser light path matching system based on Mach-Zehnder interferometer |
| CN109631959A (en) * | 2018-11-12 | 2019-04-16 | 北京航空航天大学 | A kind of atomic spin precession detection device signal anti-interference ability optimization method based on optical fiber Sagnac interference |
| CN112269155A (en) * | 2020-10-20 | 2021-01-26 | 上海理工大学 | All-fiber magnetometer device |
Non-Patent Citations (4)
| Title |
|---|
| "A compact dual atom interferometer gyroscope based on laser-cooled rubidium";T. Muller 等;《physics.atom-ph》;20081230;正文第1-8页 * |
| "In-Situ Measurement of Electrical-Heating-Induced Magnetic Field for an Atomic Magnetometer";Jixi,Lu 等;《Sensors》;20201230;第20卷(第7期);正文第1-10页 * |
| "基于圆偏振探测光的光纤原子自旋进动检测技术";杨远洪 等;《光学学报》;20190130;第39卷(第1期);正文第1-5页 * |
| "无自旋交换弛豫原子自旋陀螺非线性特性实验研究";陈东营 等;《光学学报》;20190830;第39卷(第8期);正文第1-3页 * |
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