Multi-wavelength Michelson laser based on mixed atom ensemble

Abstract

The invention discloses a multi-wavelength Michelson laser based on a mixed atom ensemble. Comprising a laser gain medium, a light splitting unit, a first rubidium-potassium mixed Faraday anomalous dispersion atomic filter, a reference arm endoscope, a first light splitting system, a second rubidium-potassium mixed Faraday anomalous dispersion atomic filter, a measuring arm endoscope, a second light splitting system, a first detection system and a second detection system. The light splitting unit performs beam splitting on the broadband spectrum signal, one beam is incident to the reference arm endoscope through a first rubidium-potassium mixed Faraday anomalous dispersion atomic optical filter, and the other beam is incident to the measurement arm endoscope through a second rubidium-potassium mixed Faraday anomalous dispersion atomic optical filter, so that two-color laser is generated in a reference arm optical path I and a measurement arm optical path II at the same time; on the basis of the co-gain and co-resonant cavity characteristics of the double-color laser, the active calibration of the cavity length and the accurate measurement of the displacement to be measured are realized. According to the invention, residual noise can be suppressed under complex background interference, and high-precision displacement measurement is realized.

Description

Technical Field

[0001] The invention belongs to the field of laser technology, and in particular relates to a multi-wavelength Michelson laser based on a mixed atomic ensemble. Background Art

[0002] As one of the seven fundamental physical quantities established by the General Conference on Metrology (CGPM), the high-precision measurement of length serves many fields such as ultra-precision machining and manufacturing, precision metrology and testing, and cutting-edge science and engineering. Ultra-precision equipment represented by lithography machines and high-end CNC machine tools have put forward higher requirements on the measurement accuracy of displacement measurement systems. Traditional mechanical measuring tools, such as vernier calipers and micrometers, can achieve micron-level measurement accuracy; grating rulers use the moiré fringes of gratings, and their displacement measurement accuracy is usually in the sub-micron level; optical interferometers based on the interference principle have a resolution of up to λ / 2, where λ is the laser wavelength, and nanometer-level measurement accuracy can be achieved with the help of electronic subdivision technology. With the development of new atomic clock technology, the current measurement accuracy of frequency has exceeded 10 -19 If the effective conversion from displacement measurement to frequency measurement can be achieved, the accuracy of displacement measurement can be greatly improved in theory.

[0003] Patent ZL202210393703.X proposes a Michelson laser that uses a single laser gain medium to provide gain for the laser oscillations of two resonant cavities (reference arm and measurement arm) at the same time. The displacement to be measured is derived from the frequency difference change of the beat frequency of the two common gain but different resonant laser modes, which can theoretically achieve a measurement accuracy of picometers or even sub-picometers. Patent ZL202410428008.1 proposes a Faraday-Michelson laser. This structure combines the frequency selection mechanism of the Faraday anomalous dispersion atomic filter on the basis of the Michelson laser, which can increase the frequency difference between the two resonant cavities and reduce the competition between laser modes. However, the above-mentioned Michelson laser is a single-frequency laser inside each resonant cavity, lacking a calibration reference for the cavity length. Affected by complex environmental changes such as mechanical vibration and temperature fluctuations, the cavity lengths of the two resonant cavities of the above-mentioned Michelson laser drift to varying degrees. This unexpected fluctuation in the cavity length directly affects the accuracy of the displacement to be measured, causing the measurement results to be submerged in the residual noise, losing its high-precision advantage in principle. The use of vacuum vibration reduction and thermal insulation technology can suppress the interference of external environmental changes on the stability of cavity length to a certain extent, but the system volume is large; the use of materials such as ultra-low expansion glass (ULE) can reduce the drift rate of cavity length, but the cost is high and the processing difficulty is greater, which limits the application and promotion of this technology. Summary of the invention

[0004] In order to overcome the influence of cavity length drift caused by environmental interference on the displacement measurement accuracy and give full play to the principle advantage of Michelson laser in high-precision displacement measurement, the present invention proposes a multi-wavelength Michelson laser based on a hybrid atomic ensemble, which utilizes the quantum transition effect of the hybrid atomic ensemble to simultaneously generate two-color lasers in the reference arm and the measurement arm, and relies on the characteristics of the two-color laser co-gain co-resonance cavity to achieve active calibration of the cavity length and accurate measurement of the displacement to be measured, and can suppress residual noise under complex background interference to achieve high-precision displacement measurement.

[0005] The multi-wavelength Michelson laser based on the mixed atomic ensemble proposed in the present invention mainly includes a laser gain medium, a rubidium potassium mixed Faraday anomalous dispersion atomic filter, a reference arm cavity mirror, a measurement arm cavity mirror, a spectroscopic system, a detection system, etc. The present invention adjusts the temperature and magnetic field strength of the rubidium potassium mixed atomic ensemble in the atomic filter (i.e., the rubidium potassium mixed gas in the atomic gas chamber inside the rubidium potassium mixed Faraday anomalous dispersion atomic filter) to make the transmission spectrum in the rubidium atomic 5S 1 / 2 →5P 3 / 2 D2 transition line (780nm), potassium atom 4S 1 / 2 →4P 3 / 2 The D2 transition line (767nm) has similar transmittance near the corresponding frequency. Using the quantum frequency selection characteristics of the rubidium potassium mixed atoms, a two-color laser with a wavelength of 780nm and 767nm is formed in the reference arm and the measurement arm respectively (the two-color laser in the reference arm is denoted as The two-color lasers in the measuring arm are respectively The two-color lasers in the reference arm and the measuring arm are separated into 780nm and 767nm lasers through the optical splitting system. and Separation, measuring arm and The separation from the reference arm and from the measuring arm The frequency difference v is obtained by detecting the beat frequency of the system 780 , the reference arm and measuring arm The frequency difference v is obtained by detecting the beat frequency of the system 767 .

[0006] Reference arm and measuring arm The two-color lasers are generated by the same resonant cavity, so the reference arm and The cavity drift of the two-color laser is the same, and the and The cavity drift of the two-color laser is the same. The present invention uses the change of the 780nm laser beat frequency signal before and after the displacement measurement as a calibration signal to monitor the cavity drift caused by the external environment fluctuation, and uses the change of the 767nm laser beat frequency signal as a test signal. The displacement change corresponding to the frequency difference change of the 767nm beat frequency signal is subtracted from the cavity length drift monitored at 780nm to eliminate the interference caused by the unexpected fluctuation of the cavity length and obtain the real displacement to be measured. (The 767nm beat frequency signal can also be used as a calibration signal, and the 780nm beat frequency signal can be used as a test signal) See the following description for details:

[0007] The laser gain medium 1 outputs a broad spectrum signal, covering both 767nm and 780nm.

[0008] The half-wave plate 2 is used to change the polarization direction of the laser and cooperate with the polarization beam splitter 3 to realize laser beam splitting. The transmitted light enters the reference arm optical path I, and the reflected light enters the measurement arm optical path II.

[0009] The reference arm optical path I comprises a first rubidium-potassium hybrid Faraday anomalous dispersion atomic filter 4 and a reference arm cavity mirror 5 .

[0010] The rubidium potassium mixed Faraday anomalous dispersion atomic filter comprises a first Glan-Taylor prism 101, a rubidium potassium mixed atomic gas chamber 102, a second Glan-Taylor prism 103, and a permanent magnet 104; wherein the polarization directions of the first Glan-Taylor prism 101 and the second Glan-Taylor prism 103 are orthogonal, and the rubidium potassium mixed atomic gas chamber 102 is filled with rubidium potassium mixed gas; and the magnetic field intensity direction of the permanent magnet 104 in the rubidium potassium mixed atomic gas chamber 102 is consistent with the light propagation direction.

[0011] Through the Faraday effect, the light reflected by the second Glan-Taylor prism 103 in the first Rb / K hybrid Faraday anomalous dispersion atomic filter 4 is reflected back to the laser gain medium 1 by the reference arm cavity mirror 5, realizing the oscillation of the laser between the laser gain medium 1 and the reference arm cavity mirror 5, generating The two-color laser is transmitted and outputted from the second Glan-Taylor prism 103 in the first rubidium-potassium mixed type Faraday anomalous dispersion atomic filter 4 .

[0012] The first light splitting system 6 realizes the reference arm optical path I Spatial separation of two-color laser light.

[0013] The optical splitting system comprises a second half-wave plate 105 , a second polarization beam splitter 106 , a potassium atom Faraday anomalous dispersion atomic filter 107 , and a rubidium atom Faraday anomalous dispersion atomic filter 108 .

[0014] The second half-wave plate 105 is used to change The polarization direction of the two-color laser light is determined by the second polarization beam splitter 106. The two-color laser is divided into two beams, one of which is transmitted through the potassium atom Faraday anomalous dispersion atomic filter 107 to filter out Achieve single wavelength The reflected light passes through the rubidium atom Faraday anomalous dispersion atomic filter 108, filtering out Single wavelength

[0015] The structures of the potassium atom Faraday anomalous dispersion atomic filter 106 and the rubidium atom Faraday anomalous dispersion atomic filter 107 are the same as the first rubidium-potassium mixed type Faraday anomalous dispersion atomic filter 4, and are filled with natural potassium and natural rubidium.

[0016] The measuring arm optical path II comprises a second rubidium-potassium mixed type Faraday anomalous dispersion atomic filter 7 and a measuring arm cavity mirror 8 .

[0017] The structure of the second rubidium potassium mixed type Faraday anomalous dispersion atomic filter 7 is the same as that of the first rubidium potassium mixed type Faraday anomalous dispersion atomic filter 4. Through the Faraday effect, the light reflected by the second Glan Taylor prism 103 of the second rubidium potassium mixed type Faraday anomalous dispersion atomic filter 7 is reflected back to the laser gain medium 1 by the measuring arm cavity mirror 8; the measuring arm cavity mirror 8 comprises a fixed cavity mirror 801, a displacement generator 802, and a dichroic mirror 803. The displacement generator 802 It is a ring structure with light passing through the middle, and generates displacement under the control of the driver (the displacement is the change in the relative distance between the fixed cavity mirror 801 and the dichroic mirror 803 before and after the displacement generator 802 generates the displacement); the rear end face of the displacement generator 802 is adhered to the fixed cavity mirror 801, and the front end face is adhered to the dichroic mirror 803; the dichroic mirror 803 is fully reflective for 767nm and fully transparent for 780nm (it can also be fully transparent for 767nm and fully reflective for 780nm).

[0018] In the measuring arm optical path II, the laser The laser oscillates between the laser gain medium 1 and the dichroic mirror 803. Oscillates between the laser gain medium 1 and the fixed cavity mirror 801; and Both of the two-color lasers are transmitted and outputted from the second Glan-Taylor prism 103 of the second rubidium-potassium mixed type Faraday anomalous dispersion atomic filter 7 .

[0019] The second light splitting system 9 realizes the measurement of the optical path II of the arm and Spatial separation; the structure of the second light splitting system 9 is the same as the first light splitting system 6.

[0020] The first detection system 10 is used to detect and Before displacement measurement, the detected frequency difference is Changing the drive of displacement generator 802 causes displacement, and the detected frequency difference is Then the beat frequency change before and after displacement measurement is according to The displacement change dL before and after the measurement can be obtained 780 , where ν 780 is the main frequency of 780nm laser, about 3.84×10 14 Hz, L 780 is the cavity length of the 780nm laser.

[0021] The second detection system 11 is used to detect and Before displacement measurement, the detected frequency difference is When the displacement generator 802 is displaced, the detected frequency difference is Then the beat frequency change before and after displacement measurement is according to The displacement change dL before and after the measurement can be obtained 767 , where ν 767 is the main frequency of 767nm laser, about 3.91×10 14 Hz, L 767 is the cavity length of the 767nm laser.

[0022] The present invention also provides a displacement measurement method of a multi-wavelength Michelson laser based on a hybrid atomic ensemble, the steps of which are: firstly receiving a first frequency difference v output by a first detection system 10; 780 , the second frequency difference v output by the second detection system 11 767 ; Then, according to the change in the 780nm laser beat frequency before and after the displacement measurement, Δv 780 And the change of 767nm laser beat frequency before and after displacement measurement Δυ 767 Derived displacement change dL sensed by 780nm laser 780 And the displacement change dL sensed by the 767nm laser 767 Among them, L 767 With L 780 Approximately equal, Since the reference arm Common cavity, measuring arm The displacement to be measured

[0023] The innovative features and beneficial effects of the technical solution provided by the present invention are:

[0024] 1. The present invention utilizes the transmission characteristics of the rubidium-potassium hybrid Faraday anomalous dispersion atomic filter to form a two-color laser with wavelengths of 780nm and 767nm in the reference arm and the measurement arm of the Michelson laser, respectively. The two-color laser uses the D2 transition line of the rubidium atom and the D2 transition line of the potassium atom as frequency references, respectively, and has the advantage of wavelength automatically corresponding to the atomic transition line;

[0025] 2. The present invention utilizes the filtering characteristics of the rubidium atom Faraday anomalous dispersion atomic filter and the potassium atom Faraday anomalous dispersion atomic filter to achieve the spatial separation of the 780nm and 767nm two-color lasers. The two-color lasers with overlapping optical paths are spatially separated into single-wavelength 780nm lasers and single-wavelength 767nm lasers;

[0026] 3. The dual-color laser common cavity realized by the present invention has the same contribution to the dual-color laser of 780nm and 767nm due to the cavity length drift caused by external environmental changes such as mechanical vibration and temperature fluctuation;

[0027] 4. The present invention uses the beat frequency difference change of the 780nm laser as a calibration signal for monitoring the cavity length drift, and subtracts the displacement change corresponding to the frequency difference change of the 767nm laser beat frequency signal from the cavity length drift monitored at 780nm, thereby eliminating the interference caused by unexpected fluctuations in the cavity length and obtaining the true displacement to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the multi-wavelength Michelson laser based on the hybrid atomic ensemble proposed in the present invention.

[0029] Figure 2 A schematic structural diagram of the Faraday anomalous dispersion atomic filter based on a mixed atomic gas chamber provided by the present invention.

[0030] Figure 3 Schematic diagram of the structure of the spectroscopic system.

[0031] Figure 4 A schematic diagram of displacement measurement using a multi-wavelength Michelson laser based on a hybrid atomic ensemble provided by the present invention.

[0032] Among them, 1-laser gain medium; 2-first half-wave plate; 3-first polarization beam splitter; 4-first rubidium potassium mixed type Faraday anomalous dispersion atomic filter; 5-reference arm cavity mirror; 6-first spectroscopic system; 7-second rubidium potassium mixed type Faraday anomalous dispersion atomic filter; 8-measurement arm cavity mirror; 801-fixed cavity mirror; 802-displacement generator; 803-dichroic mirror; 9-second spectroscopic system; 10-first detection system; 11-second detection system; 101-first Glan-Taylor prism; 102-rubidium potassium mixed type atomic gas chamber; 103-second Glan-Taylor prism; 104-permanent magnet; 105-second half-wave plate; 106-second polarization beam splitter; 107-potassium atom Faraday anomalous dispersion atomic filter; 108-rubidium atom Faraday anomalous dispersion atomic filter. DETAILED DESCRIPTION

[0033] In order to make the purpose, content, and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the accompanying drawings and examples.

[0034] like Figure 1 As shown, the device comprises:

[0035] The laser gain medium 1 outputs a wide spectrum fluorescence signal, the wavelength range of which can simultaneously cover 767nm and 780nm, providing gain for the Michelson laser.

[0036] The half-wave plate 2 is used to change the polarization direction of the laser, and the polarization beam splitter 3 is used as a splitting unit to split the incident laser into two beams, wherein the transmitted light enters the reference arm optical path I, and the reflected light enters the measuring arm optical path II; rotating the half-wave plate 2 can change the power distribution in the reference arm optical path I and the measuring arm optical path II.

[0037] The reference arm optical path I comprises a first rubidium-potassium hybrid Faraday anomalous dispersion atomic filter 4 and a reference arm cavity mirror 5 .

[0038] like Figure 2 As shown, the rubidium potassium mixed Faraday anomalous dispersion atomic filter comprises a first Glan-Taylor prism 101, a rubidium potassium mixed atomic gas chamber 102, a second Glan-Taylor prism 103, and a permanent magnet 104; wherein the polarization directions of the first Glan-Taylor prism 101 and the second Glan-Taylor prism 103 are orthogonal, and the rubidium potassium mixed atomic gas chamber 102 is filled with rubidium atoms and potassium atoms; and the magnetic field intensity direction of the permanent magnet 104 in the rubidium potassium mixed atomic gas chamber 102 is consistent with the light propagation direction.

[0039] When the frequency of the incident light is close to the D2 transition line of the rubidium atom or the D2 transition line of the potassium atom, the incident light will produce the Faraday effect in the rubidium potassium mixed atomic gas chamber 102, and its polarization direction will rotate, and it will be reflected by the second Glan-Taylor prism 103 to the reference arm cavity mirror 5; the reference arm cavity mirror 5 totally reflects the 780nm and 767nm light, and reflects the light beam back to the laser gain medium 1, realizing the oscillation between the laser gain medium 1 and the reference arm cavity mirror 5, generating The two-color laser is transmitted through the second Glan-Taylor prism 103 in the first rubidium-potassium hybrid Faraday anomalous dispersion atomic filter 4 and output to the first spectroscopic system 6 .

[0040] The first light splitting system 6 divides the light path I of the reference arm into The two-color laser is spatially separated to output single wavelength Single wavelength

[0041] The structural diagram of the optical splitting system is shown in Figure 3 As shown, it includes a second half-wave plate 105, a second polarization beam splitter 106, a potassium atom Faraday anomalous dispersion atomic filter 107, and a rubidium atom Faraday anomalous dispersion atomic filter 108.

[0042] The second half-wave plate 105 is used to simultaneously change the polarization directions of the 780nm and 767nm dual-color lasers. The second polarization beam splitter 106 divides the dual-color laser into two beams. One beam is transmitted through the potassium atom Faraday anomalous dispersion atomic filter 107. By utilizing the quantum transition characteristics, the 780nm laser can be filtered out to achieve a single-wavelength laser output of 767nm; the other beam is reflected through the rubidium atom Faraday anomalous dispersion atomic filter 108 to filter out the 767nm laser component to achieve a single-wavelength laser output of 780nm.

[0043] The structures of the potassium atom Faraday anomalous dispersion atomic filter 106 and the rubidium atom Faraday anomalous dispersion atomic filter 107 are the same as the first rubidium-potassium mixed type Faraday anomalous dispersion atomic filter 4, and the atomic gas chambers are filled with natural potassium and natural rubidium respectively;

[0044] The measuring arm optical path II comprises a second rubidium-potassium mixed type Faraday anomalous dispersion atomic filter 7 and a measuring arm cavity mirror 8 .

[0045] The second rubidium potassium mixed type Faraday anomalous dispersion atomic filter 7 has the same composition structure as the first rubidium potassium mixed type Faraday anomalous dispersion atomic filter 4. Through the Faraday effect, the light reflected by the second Glan Taylor prism 103 of the second rubidium potassium mixed type Faraday anomalous dispersion atomic filter 7 is reflected back to the laser gain medium 1 by the measuring arm cavity mirror 8; the measuring arm cavity mirror 8 comprises a fixed cavity mirror 801, a displacement generator 802, and a dichroic mirror 803, wherein the displacement generator 802 is The ring structure has a middle part that can transmit light and can be deformed under the control of a driver to generate a displacement to be measured; the rear end face of the displacement generator 802 is adhered to the fixed cavity mirror 801, and the front end face is adhered to the dichroic mirror 803; the dichroic mirror 803 fully reflects 767nm laser light and fully transmits 780nm laser light (it can also fully transmit 767nm laser light and fully reflect 780nm laser light); the fixed cavity mirror 801 fully reflects 780nm laser light.

[0046] In the measurement arm optical path II, the 767nm laser The 780nm laser is oscillated between the laser gain medium 1 and the dichroic mirror 803. Generated between the laser gain medium 1 and the fixed cavity mirror 801; The two-color lasers are both transmitted and output from the second Glan-Taylor prism 103 of the second rubidium-potassium hybrid Faraday anomalous dispersion atomic filter 7 .

[0047] The second light splitting system 9 realizes the coincidence of the light paths in the measuring arm light path II. The two-color laser is spatially separated; the structure of the second light splitting system 9 is the same as that of the first light splitting system 6 .

[0048] The schematic diagram of displacement measurement using a multi-wavelength Michelson laser based on a hybrid atomic ensemble is shown in Figure 4 As shown, the cavity length change of the Michelson laser is subdivided into three parts. The first part is the deformation of the displacement generator 802, that is, the displacement to be measured dL; the second part is the cavity drift dL of the reference arm I caused by complex environmental changes such as mechanical vibration and temperature fluctuation. ′ 1; The third part is the cavity drift dL of the measuring arm II caused by complex environmental changes such as mechanical vibration and temperature fluctuation ′ 2.

[0049] The first detection system 10 is used to detect and Before displacement measurement, the detected frequency difference is When the displacement generator 802 is deformed, the detected frequency difference is Before and after displacement measurement, the laser and The beat frequency variation between according to The displacement change dL before and after the measurement can be obtained 780 , where ν 780 is the main frequency of 780nm laser, about 3.84×10 14 Hz, L 780 is the cavity length of the 780nm laser.

[0050] The second detection system 11 is used to detect and Before displacement measurement, the detected frequency difference is When the displacement generator 802 is deformed, the detected frequency difference is Before and after displacement measurement, the laser and The beat frequency variation between 767 =v 767 (2) -v 767 (1) ;according to The displacement change dL before and after the measurement can be obtained 767 ; where ν 767 is the main frequency of 767nm laser, about 3.91×10 14 Hz, L 767 is the cavity length for 767nm laser; where,

[0051] Due to the two-color laser in the reference arm Shared cavity, dual-color laser in the measuring arm Common cavity, i.e. dL 767 and dL 780 The drift of the reference arm I cavity is dL′1, which is the same as the drift of the measurement arm II cavity. 767 and dL 780 The difference is the displacement to be measured dL, so the displacement to be measured is

[0052] The above is only a preferred embodiment of the present invention. It should be pointed out that for mixtures of other alkali metal elements and alkaline earth metal elements, multi-wavelength Michelson lasers can also be realized using the content of the present invention, which should be regarded as the protection scope of the present invention. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A multi-wavelength Michelson laser based on a hybrid atomic ensemble, characterized in that: It comprises a laser gain medium (1), a spectroscopic unit, a first rubidium-potassium mixed type Faraday anomalous dispersion atomic filter (4), a reference arm cavity mirror (5), a first spectroscopic system (6), a second rubidium-potassium mixed type Faraday anomalous dispersion atomic filter (7), a measuring arm cavity mirror (8), a second spectroscopic system (9), a first detection system (10), and a second detection system (11); The laser gain medium (1) is used to output a wide spectrum signal; The optical splitting unit is used to split the wide spectrum signal, one beam is incident on the reference arm cavity mirror (5) through the first rubidium potassium mixed type Faraday anomalous dispersion atomic filter (4), and the other beam is incident on the measuring arm cavity mirror (8) through the second rubidium potassium mixed type Faraday anomalous dispersion atomic filter (7), so as to simultaneously generate two-color laser in the reference arm optical path I and the measuring arm optical path II; wherein the optical path between the optical splitting unit and the reference arm cavity mirror (5) is used as the reference arm optical path I, and the optical path between the optical splitting unit and the measuring arm cavity mirror (8) is used as the measuring arm optical path II; the wavelengths of the two-color laser in the reference arm optical path I are respectively recorded as The wavelengths of the two-color laser in the measuring arm optical path II are respectively recorded as The first light splitting system (6) is used to spatially separate the two-color laser light in the reference arm optical path I; The second light splitting system (9) is used to spatially separate the two-color laser light in the optical path II of the measuring arm; The first detection system (10) is used to receive the wavelength separated and output by the first light splitting system (6) The laser is separated and outputted by the second optical splitting system (9) to obtain a wavelength The laser is then beat to obtain the first frequency difference v 780 ; The second detection system (11) is used to receive the wavelength separated and output by the first light splitting system (6) The laser is separated and outputted by the second light splitting system (9) to obtain a wavelength The laser is then beat to obtain the second frequency difference v 767 .

2. The multi-wavelength Michelson laser according to claim 1, characterized in that: The wavelength range of the wide spectrum signal covers both 767nm and 780nm; the transmission spectra of the first rubidium potassium mixed type Faraday anomalous dispersion atomic filter (4) and the second rubidium potassium mixed type Faraday anomalous dispersion atomic filter (7) are highly transmitted at the frequencies corresponding to the rubidium atom D2 transition line and the potassium atom D2 transition line, and highly suppressed at other frequencies, so as to generate two-color lasers with wavelengths of 780nm and 767nm.

3. The multi-wavelength Michelson laser according to claim 1, characterized in that: The structure of the second rubidium potassium mixed type Faraday anomalous dispersion atomic filter (7) is the same as that of the first rubidium potassium mixed type Faraday anomalous dispersion atomic filter (4), comprising a permanent magnet (104) and a first Glan-Taylor prism (101), a rubidium potassium mixed type atomic gas chamber (102), and a second Glan-Taylor prism (103) arranged in sequence along the light propagation direction; wherein the polarization directions of the first Glan-Taylor prism (101) and the second Glan-Taylor prism (103) are orthogonal, and the rubidium potassium mixed type atomic gas chamber (102) is filled with rubidium potassium mixed gas; and the permanent magnet (104) is used to generate a magnetic field in the rubidium potassium mixed type atomic gas chamber (102), and the direction of the magnetic field intensity is consistent with the light propagation direction.

4. The multi-wavelength Michelson laser according to claim 2, characterized in that: The light reflected by the second Glan Taylor prism (103) of the second rubidium potassium mixed type Faraday anomalous dispersion atomic filter (7) is reflected back to the laser gain medium (1) via the measuring arm cavity mirror (8); the measuring arm cavity mirror (8) comprises a fixed cavity mirror (801), a displacement generator (802), and a dichroic mirror (803); the displacement generator (802) is a ring structure with light passing through the middle, and is used to generate a displacement under the control of a driver; the rear end face of the displacement generator (802) is adhered to the fixed cavity mirror (801), and the front end face is adhered to the dichroic mirror (803); the dichroic mirror (803) is fully reflective for 767nm and fully transparent for 780nm; the wavelength in the measuring arm optical path II is The laser light oscillates between the laser gain medium (1) and the dichroic mirror (803), and the wavelength The laser light oscillates between the laser gain medium (1) and the fixed cavity mirror (801); the wavelength The dual-color laser is outputted through the second Glan-Taylor prism (103) of the second rubidium-potassium hybrid Faraday anomalous dispersion atomic filter (7).

5. The multi-wavelength Michelson laser according to claim 2, characterized in that: The light reflected by the second Glan-Taylor prism (103) in the first rubidium-potassium hybrid Faraday anomalous dispersion atomic filter (4) is reflected back to the laser gain medium (1) via the reference arm cavity mirror (5), and the wavelength generated by the oscillation between the laser gain medium (1) and the reference arm cavity mirror (5) is The dual-color laser is transmitted and outputted from the second Glan-Taylor prism (103) in the first rubidium-potassium mixed type Faraday anomalous dispersion atomic filter (4).

6. The multi-wavelength Michelson laser according to claim 2, characterized in that: The light reflected by the second Glan-Taylor prism (103) of the second rubidium-potassium mixed Faraday anomalous dispersion atomic filter (7) is reflected back to the laser gain medium (1) via the measuring arm cavity mirror (8); the measuring arm cavity mirror (8) comprises a fixed cavity mirror (801), a displacement generator (802), and a dichroic mirror (803); the displacement generator (802) is a ring structure with light passing through the middle, and is used to generate a displacement under the control of a driver; the rear end face of the displacement generator (802) is adhered to the fixed cavity mirror (801), and the front end face is adhered to the dichroic mirror (803); the dichroic mirror (803) is fully transparent to 767nm and fully reflective to 780nm, and the wavelength in the measuring arm optical path II is The laser light oscillates between the laser gain medium (1) and the dichroic mirror (803), and the wavelength The laser light oscillates between the laser gain medium (1) and the fixed cavity mirror (801); the wavelength The dual-color laser is outputted through the second Glan-Taylor prism (103) of the second rubidium-potassium hybrid Faraday anomalous dispersion atomic filter (7).

7. The multi-wavelength Michelson laser according to claim 2, characterized in that: The second light splitting system (9) has the same structure as the first light splitting system (6), and comprises a second half-wave plate (105), a second polarization beam splitter (106), a potassium atom Faraday anomalous dispersion atomic filter (107), and a rubidium atom Faraday anomalous dispersion atomic filter (108); wherein the second half-wave plate (105) is used to change the incident wavelength to The polarization direction of the two-color laser beam is then incident on the second polarization beam splitter (106), and the second polarization beam splitter (106) is used to convert the incident wavelength of The two-color laser is divided into two beams, one of which is transmitted through the potassium atom Faraday anomalous dispersion atomic filter (107) to filter out the wavelength The wavelength of the laser is Single wavelength laser output; reflected one path through the rubidium atom Faraday anomalous dispersion atomic filter (108) to filter out the wavelength The laser wavelength Single wavelength laser output.

8. The multi-wavelength Michelson laser according to claim 1, characterized in that: It also includes a half-wave plate (2), and the light splitting unit is a polarization beam splitter (3); the half-wave plate (2) is used to change the polarization direction of the two-color laser and then incident on the polarization beam splitter (3); the power distribution in the reference arm optical path I and the measurement arm optical path II is adjusted by rotating the half-wave plate (2).

9. A displacement measurement method of a multi-wavelength Michelson laser based on the hybrid atomic ensemble of claim 1, the steps of which are: first receiving a first frequency difference ν output by the first detection system (10) 780 , a second frequency difference ν output by the second detection system (11) 767 ; Then, according to the displacement measurement, the first frequency difference ν 780 The change in Δv 780 , the second frequency difference ν 767 The change in Δv 767 pass The displacement to be measured dL is calculated; where, L is the cavity length corresponding to the two-color laser; L 767 is the cavity length corresponding to the laser with wavelength of 767nm, L 780 is the cavity length corresponding to the laser with wavelength of 780nm.

10. The method according to claim 9, characterized in that A first frequency difference v caused by a displacement change of the measuring arm laparoscope (8) 780 The change in Δv 780 , the second frequency difference v 767 The change in Δv 767 ,pass The displacement dL to be measured is calculated.

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