A large laser gyroscope calibration method based on multi-wavelength measurement

Abstract

The application discloses a large laser gyroscope calibration method based on multi-wavelength measurement and relates to the technical field of laser gyroscopes. The large laser gyroscope based on multi-wavelength measurement comprises a laser light source, a ring resonator, a beam combination interference device and a signal detection device. The laser light source is used for outputting laser light of multiple wavelengths, and laser light of any wavelength is divided into two paths and injected into the ring resonator along the clockwise direction and the counterclockwise direction respectively. The ring resonator is used for resonating multiple pairs of clockwise and counterclockwise laser light with different wavelengths simultaneously. The beam combination interference device combines the laser light emitted from the output mirror of the ring resonator and separates the combined laser light according to different wavelengths. The multiple signal photoelectric detectors of the signal detection device are used for detecting the beat frequency signals of the clockwise and counterclockwise laser light of corresponding wavelengths. The application can realize real-time and accurate calibration of the large laser gyroscope by measuring the Sagnac frequency output under different laser wavelength conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser gyroscopes, and particularly relates to a large laser gyroscope calibration method based on multi-wavelength measurement. BACKGROUND

[0002] A laser gyroscope is an inertial device for measuring the rotational angular velocity of an object by using laser technology, and has the characteristics of high resolution, good stability and wide dynamic range, and has wide application prospects and important strategic significance in industrial production lines, physical experiments, astronomical observations and other fields.

[0003] The scale factor of a laser gyroscope is the ratio of the Sagnac frequency to the rotational angular velocity of the ring cavity, which reflects the sensitivity of the laser gyroscope to the input angular velocity, and the stability and accuracy of the scale factor directly affect the measurement accuracy of the laser gyroscope; the scale factor is related to the area, perimeter of the gyroscope ring cavity, wavelength of the laser, and the angle between the area normal vector of the gyroscope and the rotation axis; generally, small laser gyroscopes can be calibrated by using a turntable, which rotates at a known angular velocity or angle, and collects the output data of the laser gyroscope at the same time, and calculates the scale factor by mathematically processing the output data; for large laser gyroscopes installed on the ground for accurately monitoring the earth's rotational angular velocity, the area and perimeter are defined by the propagation path of the laser, which is difficult to accurately determine, and the turntable calibration method is not suitable, so the accurate calibration of the scale factor of the large laser gyroscope becomes a difficult problem to be solved. SUMMARY

[0004] The present application provides a large laser gyroscope calibration method based on multi-wavelength measurement, which aims to realize high-precision calibration of a large laser gyroscope.

[0005] The large laser gyroscope based on multi-wavelength measurement provided by the present application comprises a laser light source, a ring resonant cavity, a beam combining and interference device, and a signal detection device.

[0006] The laser light source is used to output laser light of multiple wavelengths, and laser light of any wavelength is divided into two paths and injected into the ring resonant cavity along the clockwise and counterclockwise directions, respectively.

[0007] The ring resonant cavity comprises an input mirror and an output mirror; the laser light of multiple different wavelengths output by the laser light source is injected into the ring resonant cavity through the input mirror, and is emitted by the output mirror after resonating in the ring resonant cavity.

[0008] The beam combining and interference device combines the laser light emitted from the output mirror, and separates the combined laser light according to different wavelengths.

[0009] The signal detection device comprises a plurality of signal photodetectors corresponding to the number of wavelengths emitted by the laser light source; each signal photodetector is used to receive the laser light processed by the beam combination interference device to detect the beat frequency signals of the laser light of the corresponding wavelength propagating in the clockwise direction and the counterclockwise direction in the ring resonator.

[0010] Optionally, the ring resonator is a square resonator composed of three input mirrors and one output mirror; the input mirror and the output mirror are high reflectivity mirrors, so that the laser light injected from one of the input mirrors propagates in the clockwise direction in the ring resonator, and the laser light injected from the other input mirror propagates in the counterclockwise direction in the ring resonator.

[0011] Optionally, the laser light output by the laser light source is coupled to the resonant mode of the ring resonator through mode matching.

[0012] Optionally, a gain medium is arranged in the ring resonator.

[0013] The gain medium is used to excite laser light of multiple wavelengths propagating in the clockwise direction and the counterclockwise direction in the ring resonator, respectively.

[0014] Optionally, the ring resonator is a square resonator composed of three input mirrors and one output mirror; the input mirror and the output mirror are high reflectivity mirrors, so that the laser light emitted by the gain medium propagates in the clockwise direction or the counterclockwise direction in the ring resonator.

[0015] Optionally, the beam combination interference device comprises a first mirror, a second mirror, a beam combiner, and a grating.

[0016] The first mirror and the second mirror are used to reflect the laser light emitted from the output mirror to the beam combiner; after the laser light emitted from the output mirror is combined by the beam combiner, the combined laser light is separated according to different wavelengths by the grating.

[0017] Optionally, the beam combination interference device is an integrated beam combination prism.

[0018] The present application provides a large laser gyroscope calibration method based on multi-wavelength measurement, which is used to calibrate the large laser gyroscope described above, and the method comprises the following steps:

[0019] S1, at least two kinds of laser light with different wavelengths are injected into the ring resonator; wherein, any wavelength of laser light is divided into two paths and injected into the ring resonator in the clockwise direction and the counterclockwise direction, respectively;

[0020] S2, measuring beat frequency signals of the laser propagating in the clockwise direction and the counterclockwise direction in the ring resonator at the same wavelength;

[0021] S3, solving the scale factor corresponding to the laser of different wavelengths by linear regression according to the earth rotation angular velocity and the beat frequency signals.

[0022] Optionally, in the step S3, the scale factor is solved according to the Sagnac formula:

[0023]

[0024] In the formula, is the Sagnac frequency; is the rotation angular velocity of the ring resonator; A is the surrounding area vector of the ring resonator, is the wavelength of the laser, P is the perimeter of the ring resonator, and 4A / P is the perimeter of the ring resonator, is the scale factor K of the large laser gyroscope s .

[0025] The application further provides a large laser gyroscope calibration tool, comprising a computer device and the large laser gyroscope described above.

[0026] The computer device comprises a memory and a processor.

[0027] The memory stores a computer program; and the processor realizes the steps of the large laser gyroscope calibration method described above when executing the computer program.

[0028] As can be seen from the above technical solution, the application has the following beneficial effects:

[0029] The application injects or excites laser signals of multiple wavelengths in the ring resonator, so that the large laser gyroscope fixed on the earth surface operates in multiple laser wavelength modes at the same time, and then outputs multiple Sagnac frequencies, i.e., the beat frequency signals of the clockwise and counterclockwise lasers of different wavelengths; the difference between the Sagnac frequencies output under different wavelengths can be calculated by linear regression to obtain the accurate value of the scale factor, so that the real-time calibration of the large laser gyroscope is realized, and the problem of accurate calibration of the large laser gyroscope is solved. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0031] Figure 1 Structure diagram of a large laser gyroscope based on multi-wavelength measurement according to the present application in embodiment 1;

[0032] Figure 2 Structure diagram of a large laser gyroscope based on multi-wavelength measurement according to the present application in embodiment 2;

[0033] Figure 3 Structure diagram of a large laser gyroscope based on multi-wavelength measurement according to the present application in embodiment 3;

[0034] Figure 4 Structure diagram of a large laser gyroscope based on multi-wavelength measurement according to the present application in embodiment 4;

[0035] Figure 5 Structure diagram of a large laser gyroscope based on multi-wavelength measurement according to the present application in embodiment 5;

[0036] Figure 6 Flow chart of a calibration method of a large laser gyroscope based on multi-wavelength measurement according to the present application.

[0037] Reference signs:

[0038] 100, ring resonator; 200, beam combination interference device; 300, signal detection device; 101, first input mirror; 102, second input mirror; 103, third input mirror; 104, output mirror; 105, gain medium; 201, first mirror; 202, second mirror; 203, beam combiner; 204, grating; 301, first signal photodetector; 302, second signal photodetector; 303, third signal photodetector; 304, fourth signal photodetector;

[0039] 1001, first resonant laser; 1002, second resonant laser; 1003, third resonant laser; 1004, fourth resonant laser; 1005, fifth resonant laser; 1006, sixth resonant laser; 1007, seventh resonant laser; 1008, eighth resonant laser. DETAILED DESCRIPTION

[0040] In order to make the purposes, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the embodiments described below are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0041] The terms "first", "second", "third", "fourth" etc. (if any) in the description and drawings of this application are used for distinguishing between similar objects, and are not necessarily used to describe a particular sequential or chronological order. It is to be understood that the use of the terms so

[0042] A laser gyroscope measures the angular velocity of a rotating object based on the Sagnac effect. The Sagnac effect was proposed by French scientist G. Sagnac in 1913. If there is a rotation in the plane of light propagation in a ring resonator, the actual optical path lengths of the clockwise and counterclockwise propagating lights are not equal. If the two counter-propagating lights in the cavity resonate with the same longitudinal mode of the ring resonator at the same time, their resonance frequencies will have a difference due to the rotation. This phenomenon satisfies the Sagnac formula:

[0043]

[0044] wherein, is the Sagnac frequency, which is the frequency difference between the clockwise and counterclockwise resonant lasers. This frequency difference is also called beat frequency. A is the area of the ring resonator, is the wavelength of the laser, and P is the perimeter of the ring resonator, is the angular velocity of the rotation of the ring resonator. In a laser gyroscope, the output Sagnac frequency is proportional to the rotation experienced by the ring resonator, and 4A / P is called the scale factor K of the laser gyroscope S .

[0045] Laser gyroscopes include small laser gyroscopes and large laser gyroscopes. Small laser gyroscopes have a small size, usually on the order of a few centimeters to tens of centimeters, and are suitable for navigation and attitude control of aerospace, ships, vehicles, missiles, etc. Large laser gyroscopes have a size of more than one meter, and are usually installed on the ground. The ring resonator of the gyroscope must be coupled with the earth, and is applied to large scientific research facilities, geodetic surveying, and professional fields with extremely high precision requirements, such as large astronomical observatories and geophysical research institutions.

[0046] The small laser gyroscope can be calibrated by a turntable. The process of calibrating the scale factor of the small laser gyroscope is a precise and complex work, which aims to ensure the accurate correspondence between the data output by the laser gyroscope and the actual rotation speed or angle. First, the preparation work is performed, including environmental stabilization and equipment state inspection. Then, the parameters of the laser gyroscope and the turntable are set to ensure that they meet the experimental requirements. After the equipment is installed, the zero offset calibration and sensitivity calibration of the laser gyroscope are performed to ensure the accuracy of the data. Then, the experiment is started, and the turntable is rotated at a known angular velocity or angle, while the data output by the laser gyroscope is collected. The collected data is processed, including denoising, filtering and correction, to ensure its accuracy and reliability. Then, the scale factor is calculated using a mathematical model or fitting algorithm, which reflects the proportional relationship between the data output by the laser gyroscope and the actual rotation speed or angle. After the scale factor is calculated, it is verified and adjusted, usually by comparing it with other measurement devices with known accuracy or by performing multiple calibration experiments to verify its accuracy and make necessary adjustments to improve the accuracy of the calibration. Finally, the determined scale factor and the detailed information of the experimental process are recorded and saved as reference values for future measurements using the laser gyroscope.

[0047] The entire calibration process of the small laser gyroscope requires strict operation procedures and precise data processing to ensure the reliability and accuracy of the laser gyroscope in high-precision applications.

[0048] The large laser gyroscope installed on the ground has an area and a circumference defined by the propagation path of the laser, which is difficult to accurately measure, and is not suitable for turntable calibration. The high-precision calibration of the large laser gyroscope is still a problem to be solved.

[0049] The present application provides a large laser gyroscope based on multi-wavelength measurement and a calibration method thereof, which aims to solve the above problems.

[0050] Referring to Figures 1 to 5 In an embodiment, the large laser gyroscope based on multi-wavelength measurement includes a laser light source, a ring resonator 100, a beam combination interference device 200 and a signal detection device 300.

[0051] The laser light source is used to output laser light of multiple wavelengths. The laser light of any wavelength is divided into two paths and injected into the ring resonator 100 in clockwise and counterclockwise directions, respectively.

[0052] The ring resonator 100 includes an input mirror and an output mirror. The laser light of multiple different wavelengths output by the laser light source is injected into the ring resonator 100 through the input mirror and exits through the output mirror after resonating in the ring resonator 100.

[0053] The beam-combining interference device 200 combines the laser beams emitted from the output mirror and separates the combined laser beams according to different wavelengths.

[0054] The signal detection device 300 includes a plurality of signal photodetectors corresponding to the number of wavelengths emitted by the laser light source; each signal photodetector is configured to receive the laser beams processed by the beam-combining interference device 200 to detect the beat frequency signals of the laser beams of the corresponding wavelength propagating in the clockwise direction and the counterclockwise direction in the ring resonator 100.

[0055] In the present embodiment, the laser beams of multiple wavelengths refer to at least two laser beams of different wavelengths, and the laser beams of the same wavelength propagating in the clockwise direction and the counterclockwise direction in the ring resonator respectively form a pair of clockwise and counterclockwise laser beams; the laser beams injected into the ring resonator 100 for resonance include at least four laser beams, and the laser beams injected into the ring resonator 100 for resonance are collectively referred to as resonance laser beams in the following description.

[0056] In an implementable embodiment, the laser light source uses a supercontinuum light source to generate laser beams covering a wide wavelength range, and combines a wavelength selection device such as a grating, a filter or a tunable filter to select a specific wavelength range or a single wavelength.

[0057] In another implementable embodiment, the laser light source uses a plurality of independent lasers to generate laser beams of different wavelengths, and then combines the laser beams of different wavelengths by a beam-combining device to inject the laser beams into the ring resonator.

[0058] In another implementable embodiment, the laser light source uses a tunable laser to continuously or discretely adjust the output wavelength within a certain wavelength range, and cooperates with a control technology to realize the switching or simultaneous output of multiple wavelengths.

[0059] In another implementable embodiment, the laser light source can also generate new wavelengths by injecting one or more fundamental frequency laser beams into a nonlinear crystal; by combining different fundamental frequency laser beams and nonlinear crystals, the generation and injection of multiple wavelengths can be realized.

[0060] In the present embodiment, the resonance laser beams are coupled to the resonance mode of the ring resonator 100 through mode matching; the coupling uses conventional optical elements such as mirrors, beam-splitting prisms, convex lenses, concave lenses, etc.

[0061] In the present embodiment, the ring resonator 100 generally includes a plurality of input mirrors and an output mirror; by injecting resonance laser beams from different input mirrors, i.e., injecting the resonance laser beams into the ring resonator 100 from different rotation directions, the clockwise laser beams or the counterclockwise laser beams described above can be obtained, and the resonance laser beams are emitted through the output mirror.

[0062] In the embodiment, the beam combination interference device 200 generally comprises at least a beam combiner and a grating. The beam combiner first combines the outgoing laser beams, and the clockwise and counterclockwise laser beams of the same wavelength are accurately superimposed to generate an interference effect. Then the grating separates the laser beams of different wavelength components. The separated laser beams are received by corresponding signal photoelectric detectors to analyze the beat frequency signals of the clockwise and counterclockwise laser beams of different wavelengths, i.e., to obtain the Sagnac frequency outputs of the clockwise and counterclockwise laser beams of different wavelengths.

[0063] In the embodiment, when the large laser gyroscope follows the rotation of the earth, due to the Sagnac effect, the optical path of the clockwise and counterclockwise laser beams through the ring-shaped light path in the ring resonator will be different, resulting in different phases when they are superimposed at the beam combination interference device, and generating a frequency difference, i.e., a beat frequency signal of the clockwise and counterclockwise laser beams of the corresponding wavelength.

[0064] Further, the embodiment can calculate the scale factor corresponding to different wavelengths according to the Sagnac formula.

[0065] Further, the embodiment can reduce the calculation error of the scale factor by linear regression mathematical method based on the Sagnac formula through the simultaneous equations of the measured different Sagnac frequencies and wavelengths.

[0066] Therefore, the embodiment measures the Sagnac frequency outputs under different laser wavelength conditions to solve the scale factor of the large laser gyroscope, and completes the calibration of the instrument. The embodiment converts the measurement of area and perimeter into the measurement of frequency, which can overcome the difficulty of high-precision determination of the photon path, and realizes the real-time and accurate calibration of the large laser gyroscope.

[0067] Based on the above embodiment, refer to Figure 1 and Figure 2 In a specific embodiment, the ring resonator 100 is a square resonator composed of three input mirrors and one output mirror. The input mirror and the output mirror are high-reflectivity mirrors, so that the resonant laser beam injected from one of the input mirrors propagates clockwise in the ring resonator 100, and the resonant laser beam injected from the other input mirror propagates counterclockwise in the ring resonator 100.

[0068] In the embodiment, the ring resonator is a passive resonator. The external laser beam is injected into the ring resonator to excite the resonance. The frequency of the resonant laser beam is locked with the resonant frequency of the ring resonator, and the difference between them is equal to the Sagnac frequency. The resonant laser beam is output from the output mirror after being enhanced by the ring resonator. The passive laser gyroscope can reduce the shot noise limit of the system by increasing the injected laser power, and has a better potential limit level.

[0069] In another specific embodiment, referring to Figure 3 , the ring resonator is provided with a gain medium.

[0070] In the embodiment, the ring resonator is an active resonator, and the gain medium is used to excite monochromatic laser beams propagating in opposite directions along clockwise and counterclockwise directions in the ring resonator, which are emitted from the output mirror after resonating in the ring resonator, and the difference between the frequencies of the two laser beams is also equal to the Sagnac frequency; the active laser gyroscope structure using the active resonator is relatively simple, and complex problems such as high-precision optical cavity mode and laser feedback locking can be avoided in the design.

[0071] Further, in a specific embodiment, in order to facilitate adjustment and optimization of the device to adapt to different experimental environments and conditions, the beam combination interference device can be built using split optical elements.

[0072] Specifically, referring to Figure 1 , the beam combination interference device 200 includes a first mirror 201, a second mirror 202, a beam combiner 203, and a grating 204.

[0073] The first mirror 201 and the second mirror 202 are used to reflect the emitted laser beams of the ring resonator 100 to the beam combiner 203; the beam combiner 203 combines the emitted laser beams of the ring resonator 100; and the grating separates the combined laser beams of different wavelengths.

[0074] In another specific embodiment, in order to improve the precision, stability and compactness of the device, the beam combination interference device can also use an integrated beam combination prism.

[0075] Based on the large laser gyroscope based on multi-wavelength measurement described above, referring to Figure 6 , in an embodiment, the calibration method of the large laser gyroscope based on multi-wavelength measurement provided by the present application includes the following steps:

[0076] S1, at least two kinds of laser beams with different wavelengths are injected into the ring resonator; wherein, the laser beams with any wavelength are divided into two paths and injected into the ring resonator along clockwise and counterclockwise directions respectively.

[0077] S2, the beat frequency signals of each pair of clockwise and counterclockwise laser beams are measured.

[0078] S3, according to the earth rotation angular velocity and the beat frequency signals of the clockwise and counterclockwise laser beams with different wavelengths, the scale factors corresponding to the laser beams with different wavelengths are solved by linear regression.

[0079] In step S3, the scale factor is solved according to the Sagnac formula:

[0080]

[0081] wherein, is the Sagnac frequency, i.e. the beat frequency of the clockwise and counterclockwise resonant lasers; is the rotation angular velocity of the ring cavity, i.e. the angular velocity of the earth rotation; A is the area vector of the ring resonant cavity, is the wavelength of the laser, P is the perimeter of the ring resonant cavity, 4A / is the scale factor K of the large laser gyroscope s .

[0082] By the difference of the output Sagnac frequencies under different wavelengths, the angular velocity of the earth rotation is determined, and the accurate value of the scale factor can be calculated by simultaneously solving the Sagnac formula corresponding to different wavelengths, so as to realize the real-time calibration of the large laser gyroscope.

[0083] Based on the foregoing embodiment of the large laser gyroscope and the calibration method thereof based on multi-wavelength measurement, the present application proposes the following specific embodiments:

[0084] Embodiment 1

[0085] Referring to Figure 1 , the large laser gyroscope based on multi-wavelength measurement comprises a ring resonant cavity 100, a beam combining interference device 200 and a signal detection device 300.

[0086] Among them, the ring resonant cavity 100 comprises a first input mirror 101, a second input mirror 102, a third input mirror 103 and an output mirror 104 arranged in a square; the beam combining interference device 200 comprises a first mirror 201, a second mirror 202, a beam combiner 203 and a grating 204; the signal detection device 300 comprises a first signal photodetector 301 and a second signal photodetector 302.

[0087] Four resonant lasers (1001, 1002, 1003, 1004) are injected into the ring resonant cavity, wherein the wavelengths of the first resonant laser 1001 and the second resonant laser 1002 are 1, and the wavelengths of the third resonant laser 1003 and the fourth resonant laser 1004 are 2; wherein the first resonant laser 1001 and the third resonant laser 1003 are injected into the ring resonant cavity 100 from the first input mirror 101 in the clockwise direction, and the second resonant laser 1002 and the fourth resonant laser 1004 are injected into the ring resonant cavity 100 from the second input mirror 102 in the counterclockwise direction.

[0088] The first resonant laser 1001 and the second resonant laser 1002 constitute a first group of clockwise and counterclockwise lasers for measuring the Sagnac frequency, and the third resonant laser 1003 and the fourth resonant laser 1004 constitute a second group of clockwise and counterclockwise lasers for measuring the Sagnac frequency.

[0089] Four beams of resonant laser are resonated in the ring resonant cavity 100, and then the laser beams of the same wavelength are combined by the combiner 203 and separated by the grating 204 after interference. Then the beat frequency signals of the first resonant laser 1001 and the second resonant laser 1002 are detected by the first signal photodetector 301 , and the beat frequency signals of the third resonant laser 1003 and the fourth resonant laser 1004 are detected by the second signal photodetector 302 .

[0090] Based on the obtained beat frequency signals and the angular velocity of the earth rotation, the simultaneous equations are obtained by the Sagnac formula:

[0091]

[0092] The different wavelengths are determined by separate measurement 1、 2, and the scale factor K of the large laser gyroscope under different wavelengths 1、 2 can be calculated S1 、K S2 .

[0093] Example 2

[0094] Referring to Figure 2 , the implementation process of the embodiment refers to Example 1, and the difference between Example 1 is that the first resonant laser 1001 and the third resonant laser 1003 of the embodiment are injected into the ring resonant cavity 100 from the third input mirror 103 in the clockwise direction.

[0095] Example 3

[0096] Referring to Figure 3 , the implementation process of the embodiment refers to Example 1, and the difference between Example 1 is that the ring resonant cavity 100 of the embodiment is an active resonant cavity, and the gain medium 105 is provided in the ring resonant cavity 100. The gain medium 105 generates gain by electric excitation to make the ring resonant cavity 100 become a ring helium-neon laser, and the first resonant laser 1001 and the third resonant laser 1003 are emitted in the clockwise direction, and the second resonant laser 1002 and the fourth resonant laser 1004 are emitted in the counterclockwise direction.

[0097] Example 4

[0098] Referring to Figure 4The embodiment is implemented by referring to the embodiment 1, and the difference between the embodiment 1 and the embodiment is that six resonant lasers (1001, 1002, 1003, 1004, 1005, 1006) are injected into the ring resonant cavity 100 in the embodiment, wherein the wavelengths of the first resonant laser 1001 and the second resonant laser 1002 are 1,the wavelengths of the third resonant laser 1003 and the fourth resonant laser 1004 are 2,the wavelengths of the fifth resonant laser 1005 and the sixth resonant laser 1006 are 3.

[0099] The first resonant laser 1001, the third resonant laser 1003 and the fifth resonant laser 1005 are injected into the ring resonant cavity 100 from the first input cavity mirror 101 in the clockwise direction, and the second resonant laser 1002, the fourth resonant laser 1004 and the sixth resonant laser 1006 are injected into the ring resonant cavity 100 from the second input cavity mirror 102 in the counterclockwise direction.

[0100] The first resonant laser 1001 and the second resonant laser 1002 constitute a first group of clockwise and counterclockwise lasers for measuring the Sagnac frequency, the third resonant laser 1003 and the fourth resonant laser 1004 constitute a second group of clockwise and counterclockwise lasers for measuring the Sagnac frequency, and the fifth resonant laser 1005 and the sixth resonant laser 1006 constitute a third group of clockwise and counterclockwise lasers for measuring the Sagnac frequency.

[0101] Correspondingly, the signal detection device 300 includes a first signal photodetector 301, a second signal photodetector 302 and a third signal photodetector 303, which respectively detect 1, 2, 3Sagnac frequencies corresponding to three pairs of different wavelength clockwise and counterclockwise lasers, and the scale factor K of the large laser gyroscope under the different wavelengths 1, 2, 3can be calculated according to the Sagnac formula and the simultaneous equations. S1 S2 S3 .

[0102] Further, the calculation error can be reduced by linear regression method to obtain more accurate scale factor value.

[0103] Embodiment 5

[0104] Referring to Figure 5The embodiment is implemented by referring to the embodiment 1, and the difference between the embodiment 1 and the embodiment is that eight resonant lasers (1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008) are injected into the ring resonant cavity 100 in the embodiment, wherein the wavelengths of the first resonant laser 1001 and the second resonant laser 1002 are 1, the wavelengths of the third resonant laser 1003 and the fourth resonant laser 1004 are 2, the wavelengths of the fifth resonant laser 1005 and the sixth resonant laser 1006 are 3, and the wavelengths of the seventh resonant laser 1007 and the eighth resonant laser 1008 are 4.

[0105] The first resonant laser 1001, the third resonant laser 1003, the fifth resonant laser 1005 and the seventh resonant laser 1007 are injected into the ring resonant cavity 100 from the first input cavity mirror 101 in the clockwise direction, and the second resonant laser 1002, the fourth resonant laser 1004, the sixth resonant laser 1006 and the eighth resonant laser 1008 are injected into the ring resonant cavity 100 from the second input cavity mirror 102 in the counterclockwise direction.

[0106] The first resonant laser 1001 and the second resonant laser 1002 constitute a first group of clockwise and counterclockwise lasers for measuring the Sagnac frequency, the third resonant laser 1003 and the fourth resonant laser 1004 constitute a second group of clockwise and counterclockwise lasers for measuring the Sagnac frequency, the fifth resonant laser 1005 and the sixth resonant laser 1006 constitute a third group of clockwise and counterclockwise lasers for measuring the Sagnac frequency, and the seventh resonant laser 1007 and the eighth resonant laser 1008 constitute a fourth group of clockwise and counterclockwise lasers for measuring the Sagnac frequency.

[0107] Correspondingly, the signal detection device 300 includes a first signal photodetector 301, a second signal photodetector 302, a third signal photodetector 303 and a fourth signal photodetector 304, which respectively detect 1, 2, 3, 4Sagnac frequencies corresponding to four pairs of different wavelength clockwise and counterclockwise lasers, and the scale factor K of the large laser gyroscope can be calculated according to the Sagnac formula and the simultaneous equations 1, 2, 3, 4of different wavelengths S1 , K S2 , K S3 , K S4 .

[0108] Further, the calculation error can be reduced by linear regression to obtain a more accurate scale factor value.

[0109] It can be seen from the above that the large laser gyroscope and the calibration method thereof based on multi-wavelength measurement according to the embodiments of the present application aim at the calibration difficulty problem of the large laser gyroscope caused by the difficulty in accurately measuring the area and the perimeter, propose a wavelength modulation scheme, measure the Sagnac frequency output under different laser wavelengths, obtain the scale factor value of the large laser gyroscope in real time, and complete high-precision calibration of the instrument; the scheme converts the measurement of the area and the perimeter into the measurement of the frequency, can overcome the difficulty in high-precision determination of the photon path, is helpful for completing high-precision measurement of the earth rotation by using the large laser gyroscope, and provides certain theoretical and experimental guidance for high-precision calibration of the large laser gyroscope in the future.

[0110] The present application also proposes a large laser gyroscope calibration tool, which in an embodiment includes a computer device and the large laser gyroscope based on multi-wavelength measurement provided by the foregoing embodiments.

[0111] In the present embodiment, the computer device includes a memory and a processor; the memory stores a computer program; and the processor realizes the steps of the foregoing embodiment of the large laser gyroscope calibration method when executing the computer program, so that the computer device can realize the technical effects that can be achieved by the method provided by the foregoing embodiments, and details are not repeated here.

[0112] In the present embodiment, the processor communicates and controls other instrument devices of the calibration tool such as the laser and the signal detection device through various interfaces when executing the computer program, so as to realize an automatic test process; in addition, the computer device also includes a data storage and management module and a data visualization module, which are convenient for an operator to query and analyze.

[0113] It can be understood by those skilled in the art that the computer program can be stored in a readable storage medium, and any reference to the memory, storage, database or other storage medium used in the present embodiment can include at least one of the non-volatile and volatile memories.

[0114] It can be understood that the large laser gyroscope calibration tool proposed by the present application can be used as a large laser gyroscope measurement system to measure the earth rotation angular velocity in real time after completing calibration of the scale factor; in this case, the computer device is also used to calculate the earth rotation angular velocity through the Sagnac formula according to the beat frequency signal and the scale factor calibrated by the above method.

[0115] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A large laser gyroscope calibration method based on multi-wavelength measurement, characterized in that, The large laser gyroscope comprises a laser light source, a ring resonator, a beam combination and interference device and a signal detection device; The laser light source is used for outputting laser light of multiple wavelengths; laser light of each wavelength is divided into two paths and injected into the ring resonator along clockwise and counterclockwise directions respectively; The ring resonator comprises an input mirror and an output mirror; laser light of multiple different wavelengths output by the laser light source is injected into the ring resonator through the input mirror, resonates in the ring resonator and is emitted by the output mirror; The beam combination and interference device combines the laser light emitted from the output mirror and separates the combined laser light according to different wavelengths; The signal detection device comprises multiple signal photoelectric detectors corresponding to the number of wavelengths emitted by the laser light source; Each signal photoelectric detector is used for receiving the laser light processed by the beam combination and interference device to detect beat frequency signals of laser light of a corresponding wavelength propagating along clockwise and counterclockwise directions in the ring resonator; The calibration method comprises the following steps: S1, injecting laser light of at least two different wavelengths into a ring resonator; wherein laser light of each wavelength is divided into two paths and injected into the ring resonator along clockwise and counterclockwise directions respectively; S2, measuring beat frequency signals of laser light of the same wavelength propagating along clockwise and counterclockwise directions in the ring resonator; S3, according to the earth rotation angular velocity and the beat signal, establishing Sagnac formula; simultaneously corresponding to the Sagnac formula of different wavelengths, through linear regression to solve the scale factor K corresponding to different wavelengths of laser s ; The Sagnac formula is as follows: ； wherein is the Sagnac frequency; is the angular velocity of rotation of the ring cavity; A is the area vector of the ring resonator, is the wavelength of the laser light, P is the perimeter of the ring resonator, 4A / is the scale factor K of the large laser gyroscope s .

2. The large laser gyro calibration method based on multi- wavelength measurement of claim 1, wherein, The ring resonator is a square resonator comprising three input mirrors and one output mirror; the input mirrors and the output mirror are high reflectivity mirrors, so that laser light injected from one of the input mirrors propagates clockwise in the ring resonator and laser light injected from the other input mirror propagates counterclockwise in the ring resonator.

3. The multi-wavelength measurement-based large laser gyroscope calibration method of claim 2, wherein, The laser light output by the laser light source is coupled to the resonant mode of the ring resonator through mode matching.

4. The multi-wavelength measurement based large laser gyro calibration method of claim 1, wherein, The ring resonator is provided with a gain medium; The gain medium is used for exciting laser light of multiple wavelengths propagating in opposite directions along clockwise and counterclockwise directions in the ring resonator.

5. The large laser gyro calibration method based on multi- wavelength measurement according to claim 4, wherein, The ring resonator is a square resonator comprising three input mirrors and one output mirror; the input mirrors and the output mirror are high reflectivity mirrors, so that laser light emitted by the gain medium propagates clockwise or counterclockwise in the ring resonator.

6. The large laser gyro calibration method based on multi- wavelength measurement of claim 1, wherein, The beam combination and interference device comprises a first mirror, a second mirror, a beam combiner and a grating; The first mirror and the second mirror are used for reflecting the laser light emitted from the output mirror to the beam combiner; after the laser light emitted from the output mirror is combined by the beam combiner, the combined laser light is separated according to different wavelengths by the grating.

7. The multi-wavelength measurement based large laser gyro calibration method of claim 1, wherein, The beam combination and interference device is an integrated beam combination prism.

8. A large laser gyro calibration tool, characterized by, The computer device and the large laser gyroscope based on multi-wavelength measurement are provided; the large laser gyroscope comprises a laser light source, a ring resonator, a beam combination and interference device and a signal detection device; The laser light source is used for outputting laser light of multiple wavelengths; laser light of each wavelength is divided into two paths and injected into the ring resonator along clockwise and counterclockwise directions respectively; The ring resonator comprises an input mirror and an output mirror; the laser light of multiple different wavelengths output by the laser light source is injected into the ring resonator through the input mirror, and after resonating in the ring resonator, is emitted by the output mirror; The beam combination interference device combines the laser light emitted from the output mirror, and separates the combined laser light according to different wavelengths; The signal detection device comprises multiple signal photodetectors corresponding to the number of wavelengths emitted by the laser light source; Each signal photodetector is used to receive the laser light processed by the beam combination interference device, so as to detect the beat frequency signals of the laser light of a corresponding wavelength propagating in clockwise and counterclockwise directions in the ring resonator; The computer device comprises a memory and a processor; The memory stores a computer program; when the processor executes the computer program, the steps of the large laser gyroscope calibration method based on multi-wavelength measurement according to any one of claims 1-7 are realized.

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