Atomic frequency stabilization and optical phase co-locked michelson laser displacement measurement system

Abstract

The application discloses a kind of atomic frequency stabilization and optical phase cooperative locking michelson laser displacement measurement system.The system includes michelson laser displacement measurement module, atomic frequency stabilization module, optical phase locking module;Michelson laser displacement measurement module includes reference sub-cavity, measurement sub-cavity, photoelectric detector, data acquisition and analysis processing module;The cavity length of reference sub-cavity is fixed, and the output frequency reference laser;The output cavity of measurement sub-cavity is installed on the object to be measured, and its cavity length changes in real time with the movement of the object to be measured, resulting in synchronous change of frequency, both satisfy =;Photoelectric detector is used to detect the beat frequency signal of reference laser and measurement laser;Data acquisition and analysis processing module is used to obtain the displacement of the object to be measured according to beat frequency signal;Optical phase locking module is used for synchronous locking of measurement laser and reference laser.The present application can realize sub-pi meter resolution displacement measurement.

Description

Technical Field

[0001] This invention belongs to the field of laser precision measurement technology, specifically relating to a Michelson laser displacement measurement system that combines atomic frequency stabilization and optical phase locking, which is particularly suitable for scenarios requiring sub-nanometer or even sub-picometer displacement resolution. Background Technology

[0002] Displacement, as one of the most fundamental geometric quantities, is crucial for high-resolution and high-precision measurement in fields such as high-end equipment manufacturing (e.g., lithography machines, precision machine tools, large telescopes), cutting-edge scientific research (e.g., gravitational wave detection, quantum precision measurement), biomedical imaging, micro-nano manipulation, inertial navigation, and aerospace. In these fields, sub-nanometer or even higher displacement accuracy is fundamental to achieving key performance indicators. Current mainstream displacement measurement technology is primarily based on laser interferometry, which offers advantages such as non-contact operation, high precision, a large measurement range, and traceability to the definition of the basic unit, the meter. However, further improvements in the displacement measurement resolution of traditional laser interferometers face technical bottlenecks (typically at the picometer level), limited by inherent factors such as electronic noise.

[0003] In recent years, displacement sensing technology based on frequency measurement has shown the potential to break through traditional limits. For example, Chinese patent application CN 202210393703.X proposes a novel Michelson laser and its displacement measurement method, the core idea of ​​which is to directly convert the displacement to be measured into a measurement of the change in laser frequency. Since frequency is one of the physical quantities with the highest measurement accuracy currently available, this scheme can theoretically achieve displacement measurement resolution better than the sub-picometer level. However, existing publicly available Michelson laser schemes generally lack effective external noise suppression mechanisms. In practical applications, factors such as mechanical vibration and thermal noise can cause fluctuations in the laser output frequency. More importantly, the environmental disturbances experienced by the two resonant cavities of the Michelson laser reference arm and measurement arm are independent and random, which leads to frequency fluctuations in the Michelson laser reference arm and measurement arm. and They will drift independently, thus generating beat frequency signals. The fluctuations in frequency limit the resolution and accuracy of displacement measurements. Existing single-frequency stabilization techniques (such as atomic frequency stabilization) are all performed on a single laser, making it difficult to simultaneously stabilize two laser resonators that are equally sensitive to noise.

[0004] Therefore, there is an urgent need to develop new noise suppression techniques based on Michelson lasers to effectively overcome the independent noise of dual cavities caused by environmental interference, so as to fully realize the potential of the innovative measurement paradigm of "geometric quantity → frequency" and achieve stable and reliable sub-picometer displacement measurement. Summary of the Invention

[0005] To fully utilize frequency, a physical quantity with high measurement accuracy and resolution, and to overcome the influence of external environmental noise on the dual-cavity structure of a Michelson laser, this invention proposes a Michelson laser displacement measurement system and method that combines atomic frequency stabilization and optical phase locking. First, the reference laser is locked to an atomic transition with ultra-high frequency stability to establish an ultra-stable frequency reference. Then, phase-locked loop technology is employed to achieve synchronous locking of the phase and frequency of the measurement laser and the reference laser, thereby effectively suppressing interference from mechanical vibration, thermal noise, and other factors on the independent noise of the dual cavities. This dual-feedback system based on atomic frequency stabilization and optical phase locking effectively decouples the noise suppression problem of the two resonant cavities, avoids mutual interference between feedback loops, and achieves better noise reduction than... To achieve horizontal laser frequency stability and thus realize displacement measurement with sub-picometer horizontal resolution, the following technical solution is adopted.

[0006] The first part is the Michelson laser displacement measurement module: This module is based on the Michelson laser structure and includes a laser gain medium, a beam splitter, high-reflectivity mirrors constituting the reference subcavity and the measurement subcavity, and a cornerstone mirror. The cavity length of the reference subcavity... The output laser frequency is fixed and used as the reference frequency. The cone-shaped reflector for measuring the cavity is mounted on the object being measured, and its cavity length... The output laser frequency changes in real time with the displacement of the object, resulting in... They change synchronously, and the two satisfy the following relationship: = ,in, and These represent the changes in the cavity length and output frequency of the measuring arm, respectively. Piezoelectric ceramics are mounted on the rear end faces of both sub-cavities for error signal feedback during cavity length adjustment and frequency locking. The device uses the beat frequency signal between the reference laser and the measuring laser for displacement measurement. Specifically, after the two laser beams are combined, their beat frequency signal is detected by a photodetector. The beat frequency signal is processed by the data acquisition and analysis module to calculate the displacement of the object under test. Beat frequency Difference in cavity length ( The change is directly related to the displacement, thus enabling real-time measurement of the displacement.

[0007] The second part is the atomic frequency stabilization module for the reference laser: to suppress environmental interference affecting the laser frequency of the reference subcavity. To mitigate the impact of external interference and improve the long-term stability of the reference frequency, this invention employs an atomic frequency stabilization module. This module utilizes atomic transition spectral lines (such as rubidium, cesium, and potassium atoms) as a frequency reference, locking the laser frequency at these atomic transitions, thereby effectively suppressing external interference and improving frequency stability. Taking modulation-transfer spectrum frequency stabilization as an example, a portion of the laser output from the Michelson laser is split, and after polarization beam splitting, it is divided into pump light and probe light. The pump light generates a modulation sideband through an electro-optic modulator, which coincides with the probe light in the atomic gas cell. Through a nonlinear four-wave mixing effect, the modulation is transferred to the probe light. A photodetector detects the probe light signal carrying the modulation information. The atomic frequency stabilization locking circuit modulates and demodulates the probe signal, extracts the error signal, and feeds this error signal back to the piezoelectric ceramic controlling the cavity length of the reference sub-cavity, thereby setting the reference laser frequency... Precisely locking onto atomic transition spectral lines ensures extremely high stability of the reference frequency. Using this technique, the frequency stability of the reference laser can be improved to [a certain level]. level.

[0008] Furthermore, if frequency stabilization is achieved by combining it with a high-precision optical cavity (PDH) or by using technologies such as cold atom optical clocks as a reference, this frequency stability can be further improved to [a higher level]. ~ level.

[0009] The third part is the optical phase-locking module for the reference-measurement laser: to further suppress environmental interference on the laser frequency of the measurement subcavity. To mitigate the influence of the reference laser and achieve precise and controllable displacement, this invention incorporates a phase-locking module. The core of this module is the beat frequency microwave signal between the measuring laser and the reference laser. By locking onto an external high-precision quantum frequency reference (such as a rubidium atomic clock or a cesium atomic clock), measurement accuracy is improved while ensuring traceability. The device first acquires the beat frequency signals of the reference laser and the measurement laser through a photodetector. These beat frequency signals are then divided and amplified before being input to a phase detector. Simultaneously, a signal generator driven by the external quantum frequency reference produces a highly stable frequency. The reference microwave signal is also input to the phase detector. The phase detector compares... and These two signals output an error signal containing information about frequency and phase differences. This signal is filtered by a loop filter to remove high-frequency noise and clutter, and then processed by a proportional-integral-differential circuit to generate a precise error signal that is fed back to the piezoelectric ceramic controlling the cavity length of the measurement sub-cavity, dynamically adjusting the measurement laser frequency. Make the beat frequency signal Strictly locked to an external quantum frequency reference, this optical phase-locked loop (OPLL) structure effectively suppresses the influence of external environmental disturbances on the measurement optical path, ensuring a constant phase difference between the measurement laser frequency and the reference laser frequency. Simultaneously, by setting the frequency value of the external quantum frequency reference, the beat frequency can be precisely controlled. This allows for precise control of the change in the length of the measuring sub-cavity, enabling accurate control and measurement of the displacement.

[0010] Furthermore, the laser gain medium can be a gas gain medium, a semiconductor gain medium, or a solid medium, but it is necessary to ensure that its gain is high enough to ensure that both sub-cavities can achieve laser oscillation after beam splitting.

[0011] Furthermore, passive solutions can be adopted to reduce interference from environmental factors such as mechanical vibration and thermal disturbance, ensuring that the laser can stably oscillate during the movement of the cavity mirror. For example, the reference cavity mirror and measuring cavity mirror can be replaced with a pyramidal array to further improve robustness; the Michelson laser system can be installed in an active vibration isolation platform and vacuum device to minimize the impact of mechanical vibration and thermal noise on the effective cavity length of the Michelson laser.

[0012] Furthermore, besides modulation transfer spectroscopy, other techniques for atomic frequency stabilization include saturated absorption spectroscopy, frequency modulation spectroscopy, polarization spectroscopy, and dual-frequency Doppler-free spectroscopy. Essentially, these techniques utilize highly stable atomic transitions to lock the laser frequency. Additionally, techniques such as Pound-Drever-Hall can be employed to further enhance short-term frequency stability.

[0013] A method for measuring Michelson laser displacement using atomic frequency stabilization and optical phase co-locking includes the following steps:

[0014] 1) Lock the reference laser onto an atomic transition with the required ultra-high frequency stability, using the output frequency as... The reference laser is used as an ultra-stable frequency standard; the measurement laser is used to monitor the movement caused by the object under test.

[0015] 2) Phase-locked loop (PLL) technology is used to synchronize the phase and frequency of the measuring laser and the reference laser;

[0016] 3) Detect the beat frequency signal between the reference laser and the measurement laser. , To measure the frequency of the laser;

[0017] 4) Based on the beat frequency signal The displacement of the object under test is calculated.

[0018] Compared with existing technologies, the positive effects of the Michelson laser based on atomic frequency stabilization and phase-locked loop proposed in this invention are as follows.

[0019] 1. Improved Measurement Resolution: Through dual high-precision frequency stabilization technologies—atomic frequency stabilization and optical phase-locked loop—the independent noise of the Michelson laser's dual cavities caused by environmental disturbances is systematically suppressed, improving the overall stability of the laser frequency to [percentage missing]. At or above the level, it has achieved and maintained a displacement measurement resolution on the subpicometer (<1 pm) level, breaking through the technical limit of traditional laser interferometric displacement measurement.

[0020] 2. Ultra-high stability and robustness: Reference frequency Locked onto atomic spectral lines, it provides a long-term stable absolute frequency reference; frequency measurement Through optical phase-locked loop and Maintaining a strict frequency / phase relationship with an external quantum frequency reference ensures the system's high-precision measurement capabilities and reliability in complex environments. Combined with optional passive anti-interference measures (array mirrors, vibration isolation, vacuum), the system's robustness is further enhanced.

[0021] 3. Precise and controllable displacement: By adjusting the frequency of the external reference signal of the phase-locked loop. It can directly and accurately control the displacement of the measuring mirror. This provides a new means for nano-positioning and precision motion control.

[0022] 4. Innovative measurement paradigm, displacement measurement traceable to national standards: The revolutionary measurement paradigm of "geometric displacement → laser frequency difference → locked to quantum frequency benchmark" has been successfully implemented, which cleverly avoids the fundamental limitations of diffraction limit and electronic noise on resolution in traditional optical interferometry. At the same time, by comparing the measurement results with national frequency standards, the traceability of displacement measurement results can be verified, ensuring the accuracy of the test results.

[0023] 5. Wide applicability: This system provides key core measurement technology support for cutting-edge fields that require sub-nanometer or even sub-picometer level displacement measurement accuracy, such as lithography machine overlay precision measurement and compensation, ultra-high precision scanning of atomic force / scanning tunneling microscope (AFM / STM), gravitational wave detection mirror displacement monitoring, space precision orbit determination, and the construction of quantum precision measurement experimental platforms. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a Michelson laser structure based on atomic frequency selection and phase-locking.

[0025] Figure 2 This is a diagram of the modulation transfer spectrum optical path structure used for reference laser frequency locking.

[0026] The system comprises: 101 - Michelson laser system: 1001 - High reflectivity mirror; 1002 - Laser gain medium; 1003 - Beam splitter; 1004 - Reference pyramid; 1005 - First piezoelectric ceramic; 1006 - Measuring pyramid; 1007 - Second piezoelectric ceramic; 1008 - Half-wave plate; 1009 - Polarizing beam splitter prism; 1010 - Photodetector; 1011 - Data acquisition and analysis module. 201 - Atomic frequency-stabilized optical path: 2001 - Second half-wave plate; 2002 - Second polarizing beam splitter prism; 2003 - Atomic gas cell; 2004 - Third polarizing beam splitter prism; 2005 - Second high reflectivity mirror; 2006 - Third half-wave plate; 2007 - Electro-optic modulator; 2008 - Third high reflectivity mirror; 2009 - Second photodetector. 202 - Atomic frequency stabilization lock-in circuit; 3001 - Amplifier and frequency divider; 3002 - Phase detector; 3003 - Signal generator; 3004 - External frequency reference; 3005 - Loop filter; 3006 - PID proportional-integral-differential circuit. Detailed Implementation

[0027] The following examples are used to explain the technical solutions of the present invention in a non-limiting manner.

[0028] like Figure 1 As shown, the Michelson laser system based on atomic frequency stabilization and phase locking mainly consists of three parts: the basic structure of the Michelson laser, the atomic frequency stabilization module of the reference laser, and the optical phase locking module between the reference laser and the measurement laser.

[0029] The first part describes the basic structure of a Michelson laser and its displacement measurement module. The Michelson laser mainly includes a laser gain medium 1002, a beam splitter 1003, and a high-reflectivity mirror 1001, a reference pyramid 1004, and a measurement pyramid 1006, which form two sub-resonant cavities for reference and measurement. A first piezoelectric ceramic 1005 and a second piezoelectric ceramic 1007 are attached to the rear end faces of both pyramids for error signal feedback during cavity length adjustment and frequency locking of the two sub-resonant cavities. The light emitted from the laser gain medium 1002 is split into two paths by the beam splitter 1003, forming two resonant cavities: the high-reflectivity mirror 1001, beam splitter 1003, and reference pyramid 1004 constitute the reference sub-cavity, with a cavity length set to... The corresponding reference laser frequency is The position of the reference pyramid 1004 is fixed, corresponding to the frequency. For reference, used in frequency measurement after beat frequency; the high-reflectivity mirror 1001, beam splitter 1003, and measuring cone 1006 constitute the measuring subcavity, whose cavity length and frequency are respectively set as follows: and The measuring cone 1006 is mounted on the object under test, which is in a moving position, and the corresponding frequency. It keeps synchronized with the cavity length change in real time, so that the beat frequency signal can be acquired and processed through the half-wave plate 1008-polarizing beam splitter prism 1009-photodetector 1010-data acquisition and analysis processing module 1011 to realize displacement measurement.

[0030] The second part is the atomic frequency stabilization module for the reference laser, mainly including the atomic frequency stabilization optical path 201 and the atomic frequency stabilization locking circuit 202. As an optional embodiment, Figure 2 An atomic frequency-stabilized optical path based on modulation transfer spectrum is provided. The output laser of the Michelson laser 101 is split into two paths for laser frequency stabilization of the reference arm. After passing through the second half-wave plate 2001 and the second polarization beam splitter 2002, the light is split into two paths. One path is reflected as pump light, which, after being reflected by the second high-reflectivity mirror 2005, enters the electro-optic modulator 2007 for modulation to generate a first-order sideband. The third half-wave plate 2006 is placed in front of the electro-optic modulator 2007 to ensure that the laser polarization direction is parallel to the optical axis of the electro-optic crystal. The pump light carrying the modulation signal, after being reflected by the third high-reflectivity mirror 2008 and the third polarization beam splitter 2004, enters the atomic gas cell and coincides with the transmitted light (probe light) after passing through the second polarization beam splitter 2002. Through a nonlinear four-wave mixing effect, the modulation is transferred to the probe light. Therefore, the beat frequency signal between the modulation sideband and the probe light can be detected by the second photodetector 2009. Furthermore, after the signal is modulated and demodulated by the atomic frequency stabilization and locking circuit 202, an error signal is obtained and fed back to the first piezoelectric ceramic 1005 of the Michelson laser 101, thereby suppressing the influence of external interference on the laser frequency of the reference arm.

[0031] The third part is the optical phase-locking module for the reference and measurement lasers. Its main function is to synchronously lock the measurement laser and the reference laser, suppressing interference from independent noise in the dual cavities. Figure 1 As shown, the measurement and reference laser output from the Michelson laser passes through photodetector 1010, and a portion of it is split off by a power divider for phase locking, thereby converting the beat frequency microwave signal... Locked to the external quantum frequency reference 3004 microwave frequency Above. The external reference signal is generated by a signal generator 3003 that receives an external frequency reference, such as a rubidium atomic clock or a cesium atomic clock. This signal is then compared with the Michelson microwave signal. Phase detection is performed. An optical phase-locked loop (PLL) is used. Since there is a frequency difference between the reference laser and the measurement laser, a photodetector 1010 detects this beat frequency, converting the optical signal into an electrical signal. After processing by a frequency divider and amplifier 3001, the signal is transmitted to a phase detector 3002. This performs frequency and phase detection processing between the beat signal and the external reference signal, obtaining an error signal containing frequency and phase information. A loop filter 3005 filters out high-frequency noise and clutter from the error signal. Finally, a proportional-integral-differential circuit 3006 processes the signal to generate a precise error signal, which is then fed back to the second piezoelectric ceramic 1007 to control the frequency of the measurement laser. This ensures that the frequency and phase difference between the reference laser and the measurement laser remain constant, thus suppressing the influence of external environmental interference on the measurement laser optical path. Simultaneously, by controlling the frequency value of the external frequency reference in the PLL, the displacement of the measurement cavity mirror can be accurately controlled, achieving precise displacement measurement. This displacement generation and measurement equipment has important applications in lithography machines and atomic-level manufacturing.

[0032] Furthermore, the laser gain medium can be a gas gain medium, a semiconductor laser gain medium, or a solid medium, but it is necessary to ensure that its gain is high enough to ensure that both sub-cavities can achieve laser oscillation after beam splitting.

[0033] Furthermore, passive solutions can be adopted to reduce interference from environmental factors such as mechanical vibration and thermal disturbance, ensuring that the laser can stably oscillate during the movement of the cavity mirror. For example, the reference cavity mirror and measuring cavity mirror can be replaced with a pyramidal array to further improve robustness; the Michelson laser system can be installed in an active vibration isolation platform and vacuum device to minimize the impact of mechanical vibration and thermal noise on the effective cavity length of the Michelson laser.

[0034] Furthermore, in addition to modulation transfer spectrum, other technologies for atomic frequency stabilization include saturated absorption spectrum, frequency modulation spectrum, polarization spectrum, and dual-frequency Doppler-free spectrum. Essentially, these technologies utilize highly stable atomic transitions to lock the laser frequency onto the transition.

[0035] This invention also provides a method for measuring Michelson laser displacement by co-locking atomic frequency stabilization and optical phase, the steps of which include:

[0036] 1) Lock the reference laser onto an atomic transition with the required ultra-high frequency stability, using the output frequency as... The reference laser is used as an ultra-stable frequency standard; the measurement laser is used to monitor the movement caused by the object under test.

[0037] 2) Phase-locked loop (PLL) technology is used to synchronize the phase and frequency of the measuring laser and the reference laser;

[0038] 3) Detect the beat frequency signal between the reference laser and the measurement laser. , To measure the frequency of the laser;

[0039] 4) Based on the beat frequency signal The displacement of the object under test is calculated.

[0040] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Those skilled in the art can modify or make equivalent substitutions to the technical solutions of the present invention without departing from the spirit and scope of the appended claims. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the specific scope of protection is determined by the scope defined in the claims.

Claims

1. A Michelson laser displacement measurement system that combines atomic frequency stabilization and optical phase locking, characterized in that, It includes a Michelson laser displacement measurement module, an atomic frequency stabilization module for the reference laser, and an optical phase-locking module for the reference-measurement laser; The Michelson laser displacement measurement module includes a reference subcavity, a measurement subcavity, a photodetector, and a data acquisition and analysis module; the cavity length of the reference subcavity is... Fixed output frequency The reference laser; the output cavity mirror of the measuring sub-cavity is mounted on the object under test, and its cavity length... The frequency of the output measurement laser changes in real time as the object under test moves. Synchronous changes, both satisfy = ,in, The change in the length of the measured sub-cavity. The measurement subcavity represents the change in output frequency; the photodetector is used to detect the beat frequency signal between the reference laser and the measurement laser. The data is then input into the data acquisition and analysis module; the data acquisition and analysis module is used to process the beat frequency signal. The displacement of the object under test is calculated. The atomic frequency stabilization module uses atomic transition spectral lines as a frequency reference to determine the frequency of the reference laser. By focusing on atomic transitions, frequency stability is improved; The optical phase-locking module is used to synchronize the phase and frequency of the measuring laser and the reference laser using phase-locked loop technology, thereby suppressing the interference of mechanical vibration and thermal noise on the frequency of the measuring laser. The optical phase-locked module includes an amplifier and frequency divider (3001), a phase detector (3002), a signal generator (3003), an external frequency reference (3004), a loop filter (3005), and a PID proportional-integral-differential circuit (3006); the amplifier and frequency divider (3001) controls the beat frequency signal. After frequency division and amplification, the signal is input to the phase detector (3002); the signal generator (3003) driven by the external frequency reference (3004) generates the frequency. The reference microwave signal is input to the phase detector (3002); the phase detector (3002) compares the input beat frequency signal and the reference microwave signal, and outputs an error signal containing frequency and phase difference information; the loop filter (3005) filters out high-frequency noise and clutter in the error signal, and the PID proportional-integral-differential circuit (3006) processes and feeds back to control the cavity length of the measuring sub-cavity, dynamically adjusting the frequency of the measuring laser. Make the beat frequency signal Locked to an external quantum frequency reference; The Michelson laser displacement measurement module includes a Michelson laser, which comprises a laser gain medium (1002), a beam splitter (1003), a high reflectivity mirror (1001), a reference pyramid (1004), and a measuring pyramid (1006). A first piezoelectric ceramic (1005) is disposed on the reference pyramid (1004), and a second piezoelectric ceramic (1007) is disposed on the measuring pyramid (1006). The light emitted by the laser gain medium (1002)... The light is split into two paths by a beam splitter (1003) and incident on a reference cone (1004) and a measuring cone (1006) respectively. The high reflectivity mirror (1001), the beam splitter (1003), and the reference cone (1004) constitute the reference sub-cavity, and the position of the reference cone (1004) is fixed. The high reflectivity mirror (1001), the beam splitter (1003), and the measuring cone (1006) constitute the measuring sub-cavity, and the measuring cone (1006) is mounted on the object to be measured. The PID proportional-integral-differential circuit (3006) processes and generates an error signal, which is fed back to the second piezoelectric ceramic (1007) to control the cavity length of the measuring sub-cavity; The atomic frequency stabilization module includes an atomic frequency stabilization optical path (201) and an atomic frequency stabilization locking circuit (202). The atomic frequency stabilization optical path (201) includes a second half-wave plate (2001), a second polarization beam splitter (2002), an atomic gas cell (2003), a third polarization beam splitter (2004), a second high reflectivity mirror (2005), a third half-wave plate (2006), an electro-optic modulator (2007), a third high reflectivity mirror (2008), and a second photodetector (2009). The laser output from the Michelson laser is split into two paths by the polarization beam splitter 1009. One path is input to the photodetector, and the other path is split into two paths after passing through the second half-wave plate (2001) and the second polarization beam splitter (2002). The reflected path is used as pump light and passes through the second high reflectivity mirror (2008) in sequence. The mirror (2005) and the third half-wave plate (2006) are input into the electro-optic modulator (2007) for modulation to generate a first-order sideband. The third half-wave plate (2006) is used to ensure that the laser polarization direction is parallel to the optical axis of the electro-optic crystal. The pump light carrying the modulation signal output by the electro-optic modulator (2007) is reflected by the third high reflectivity mirror (2008) and the third polarization beam splitter (2004) and then enters the atomic gas cell (2003). It coincides with the transmitted light after passing through the second polarization beam splitter (2002). The light output by the atomic gas cell (2003) is detected by the second photodetector (2009) to obtain the beat frequency signal of the modulation sideband and the detection light. The signal is then input into the atomic frequency stabilization and locking circuit (202) for modulation and demodulation to obtain an error signal that is fed back to the first piezoelectric ceramic (1005).

2. The system according to claim 1, characterized in that, The laser gain medium (1002) is a gas gain medium, a semiconductor laser gain medium, or a solid medium.

3. The system according to claim 1, characterized in that, The reference pyramid (1004) and the measuring pyramid (1006) are a pyramid array.

4. The system according to claim 1, characterized in that, The Michelson laser is located within the active vibration isolation platform and vacuum device.

5. A displacement measurement method based on the atomic frequency stabilization and optical phase-locked Michelson laser displacement measurement system as described in claim 1, comprising the following steps: 1) Lock the reference laser onto an atomic transition with the required ultra-high frequency stability, using the output frequency as... The reference laser is used as an ultra-stable frequency standard; the measurement laser is used to monitor the movement caused by the object under test. 2) Phase-locked loop (PLL) technology is used to synchronize the phase and frequency of the measuring laser and the reference laser; 3) Detect the beat frequency signal between the reference laser and the measurement laser. , To measure the frequency of the laser; 4) Based on the beat frequency signal The displacement of the object under test is calculated.

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