A high-precision laser measuring optical axis alignment device and method with universality

Abstract

The application discloses a kind of high-precision laser measurement optical axis alignment device and method with universality, solve the problem that the alignment precision of existing laser optical axis alignment technology is low, and the difficulty of spot coincidence is big, specifically including light splitting system, stray light measurement system, laser interference displacement measurement system and optical axis alignment measurement system;Light splitting system includes first light splitting prism, second light splitting prism and third light splitting prism;Laser interference displacement measurement system includes dual-frequency laser and laser interference displacement measurement unit;Optical axis alignment measurement system includes position detector, fiber coupler, receiver, acquisition card and host computer;The application utilizes the independence of interference fringe formed by laser interference displacement measurement unit and bidirectional measurement, forms universal high-precision laser measurement optical axis alignment device.The device realizes optical axis alignment by adjusting interference fringe, reference spot and measurement spot, and can obtain high-precision optical axis alignment degree.

Description

Technical Field

[0001] This invention relates to a laser optical axis alignment device and method, specifically to a universally applicable high-precision laser measurement optical axis alignment device and method. Background Technology

[0002] In the field of ultra-wide field-of-view acquisition for high-power laser communication, there is an urgent need to overcome the challenge of highly robust alignment techniques at ultra-high speeds; similarly, in the field of long-distance transmission detection for laser fusion, there is a pressing need for research on highly precise optical path alignment. Laser interferometry devices possess ultra-precise resolution capabilities, with measurement accuracy reaching several nanometers, enabling high-precision optical axis alignment and field-of-view measurement. However, in practical applications, optical axis alignment techniques often employ photodetectors to detect the position and energy levels of the input light spot to determine the location of the laser optical axis center. This method is limited by the recognition and resolution capabilities of the photodetector, making it impossible to achieve ultra-precise and ultra-wide field-of-view resolution.

[0003] In the mid-1960s, the United States pioneered research into space laser communication. A robust acquisition-tracking-aiming system, developed collaboratively by NASA, AF, and JPL, was tested using an 810nm beacon beam and a 1550nm communication beam in an inter-satellite communication link, achieving a communication speed of up to 2.5 Gbit / s. From 1998 to 2001, the European Space Agency (ESA) successfully established the world's first high-precision inter-satellite laser alignment communication link, achieving a communication speed of 50 Mbit / s. In 2016, it achieved a laser beam divergence angle of 14 μrad and a communication distance of [missing information]. The communication rate reached 1.8Gbps over a distance of 45,000km; Harbin Institute of Technology achieved a 5Gbps transmission rate with high-precision triangulation over 40,000km between satellite and ground for the first time in 2017; in 2016, the "Micius" satellite completed high-precision alignment detection over a distance of 2,000km between satellite and ground, achieving a transmission rate of 5.12Gbps by using binary phase-shift keying coherent detection and a 1550nm communication wavelength; and in 2017, the Changchun Institute of Optics, Fine Mechanics and Physics conducted full-duplex laser communication within an 8km range, achieving a rate of 2.5Gbps. In 1984, Wang Wucheng et al. used an imaging system and two quadrant tubes to monitor the optical axis drift and the optical axis and pupil state, achieving an optical axis correction accuracy of 0.5″ and a pupil correction accuracy of 100μm. Based on this, in 2008, Wei Pengfei et al. used a CCD imaging device for dual reference point alignment, calculating the feedback of the spot position change and reference point offset, achieving an adjustment accuracy of 0.5μrad and a feedback control frequency of approximately 1Hz. Based on this, in 2010, Zhou Wei et al. also used a CCD receiver, employing a dual-pinhole symmetrical distribution and pupil alignment to achieve cavity mirror (CM) alignment. In 2011, Yang Rong used a Hartmann sensor and a fast tilting mirror to achieve optical path coupling alignment technology between two optical platforms, achieving an optical axis alignment error better than 1.2″ and a pupil alignment error better than 0.5mm.

[0004] Nevertheless, for higher-precision laser optical axis alignment technology, the above methods still have problems such as low optical axis alignment accuracy, difficulty in aligning and matching optical spots, and insufficient resolution in optical spot overlap measurement. Summary of the Invention

[0005] The purpose of this invention is to provide a universally applicable high-precision laser measurement optical axis alignment device and method to solve the technical problems of low alignment accuracy, difficulty in spot overlap and alignment, and insufficient resolution of spot overlap measurement in existing laser optical axis alignment technologies.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A universal, high-precision laser measurement optical axis alignment device is used for aligning the optical axis of a laser to be aligned with that of a real-time test unit. Its special feature is that it includes a beam splitting system, a stray light measurement system, a laser interferometric displacement measurement system, and an optical axis alignment measurement system.

[0008] The beam splitting system includes a first beam splitting prism, a second beam splitting prism, and a third beam splitting prism;

[0009] The laser interferometric displacement measurement system includes a dual-frequency laser and a laser interferometric displacement measurement unit;

[0010] The optical axis alignment measurement system includes a position detector, an optical fiber coupler, a receiver, a data acquisition card, and a host computer.

[0011] The first beam splitter is disposed between the laser to be aligned and the real-time test unit, and the first beam splitter and the real-time test unit are located sequentially on the first reflected light path of the second beam splitter; the second beam splitter and the third beam splitter are disposed sequentially between the dual-frequency laser and the laser interference displacement measurement unit, and the second beam splitter is located on the second reflected light path of the first beam splitter.

[0012] The position detector is located on the first reflected optical path of the first beam splitter and is used to obtain the first reference spot and the first measurement spot during pre-alignment. Its output end is connected to the input end of the data acquisition card. The fiber optic coupler is located on the second reflected optical path of the third beam splitter and is used to obtain the first interference signal during alignment. Its output end is connected to the input end of the data acquisition card. The receiver is located on the second reflected optical path of the second beam splitter and is used to obtain the second reference spot, the second interference signal, and the second measurement spot during pre-alignment. Its output end is connected to the input end of the data acquisition card.

[0013] The output terminal of the acquisition card is connected to the input terminal of the host computer;

[0014] The host computer is used to calculate the azimuth angle information ΔL between the laser to be aligned and the dual-frequency laser based on the first reference spot and the first measurement spot, and to obtain the offset Δα between the optical axis of the real-time test unit and the laser interference displacement measurement unit based on the second reference spot and the second measurement spot, as well as the first interference signal and / or the second interference signal.

[0015] Furthermore, the optical axis alignment measurement system also includes a reflection unit disposed in the optical path between the first beam splitter and the position detector;

[0016] The reflecting unit includes a first reflecting mirror and a second reflecting mirror;

[0017] The first and second reflectors are arranged opposite to and parallel to each other, and are used to reflect the first reflected light from the first beam splitter multiple times.

[0018] Furthermore, the wavelength stability range of the dual-frequency laser is ±2ppb.

[0019] Furthermore, the splitting ratio of the second beam-splitting prism is 1:1;

[0020] The third beam splitter has a beam splitting ratio of 1:9, with 90% of the light transmitted through it.

[0021] Furthermore, the surface profiles of the first and second reflectors are less than λ / 10, where λ is the laser wavelength.

[0022] Furthermore, the receiver has a receivable wavelength range of 300–1550 nm.

[0023] A universally applicable, high-precision laser measurement optical axis alignment method, characterized by the following steps:

[0024] Step 1: Construct a universal, high-precision laser measurement optical axis alignment device as described above;

[0025] Step 2: Turn on the laser to be aligned and pre-align the laser to be aligned with the real-time test unit. Then the position detector obtains the first reference spot and the receiver obtains the second reference spot. Make the first reference spot completely aligned with the center of the crosshair of the position detector.

[0026] Step 3: Turn off the laser to be aligned and turn on the dual-frequency laser. The position detector will obtain the first measurement spot, the fiber coupler will obtain the first interference signal, and the receiver will obtain the second interference signal and the second measurement spot.

[0027] Step 4: The host computer acquires the position information of the first reference spot and the first measurement spot through the acquisition card; and calculates the azimuth angle information ΔL between the laser to be aligned and the dual-frequency laser using the first reference spot and the first measurement spot.

[0028] Step 5: Based on the azimuth angle information ΔL obtained in Step 4, adjust the pose of the dual-frequency laser and the second beam splitter so that the overlap of the position information of the first reference spot and the first measurement spot is greater than or equal to a preset value; synchronously adjust the pose of the laser interference displacement measurement unit so that the spot of the second interference signal is located at the center of the optical axis of the receiver photosensitive surface.

[0029] Step 6: The host computer acquires the second reference spot, the second measurement spot, the first interference signal, and / or the second interference signal through the acquisition card. The second measurement spot replaces the second reference spot. Based on the second measurement spot and the second interference signal, the angular offset α between the corresponding optical axes is calculated. Furthermore, based on the first or second interference signal, the measured displacement ΔZ of the laser interferometric displacement measurement unit and the number of interference fringes m are calculated. Finally, the correspondence between the measured displacement ΔZ and the number of interference fringes m is calculated.

[0030]

[0031] In the formula, λ is the laser wavelength;

[0032] Step 7: Calculate the offset Δα of the optical axis between the real-time test unit and the laser interferometric displacement measurement unit based on the calculation results of Step 6:

[0033] Δα=arctan((D3+ΔZ)Z)-α

[0034] Where D3 is the spot radius of the second reference spot or the second measurement spot, and Z is the vertical distance between the photosensitive surface of the receiver and the central axis of the second beam splitter.

[0035] Step 8: Adjust the real-time test unit based on the offset Δα calculated in step 7, so that the second measurement spot received by the receiver coincides with the second interference signal, thus completing the alignment of the laser to be aligned with the real-time test unit.

[0036] Furthermore, in step 5, the preset value is 85%.

[0037] Furthermore, in step 5, the overlap S between the first reference spot and the first measurement spot is calculated using the following formula. 重合 :

[0038]

[0039] In the formula: D1 is the radius of the first reference spot; θ1 is the change in the angle of the coincidence point of the first reference spot and the first measurement spot relative to the center of the first reference spot; θ2 is the change in the angle of the coincidence point of the first measurement spot and the first reference spot relative to the center of the first measurement spot; and D2 is the radius of the first measurement spot.

[0040] The beneficial effects of this invention are:

[0041] 1. Compared with existing technologies, this invention highlights the use of interference fringes formed by a laser interferometric displacement measurement unit and the independence of bidirectional measurement to create a universal, high-precision laser measurement optical axis alignment device. This device achieves optical axis alignment by adjusting the interference fringes, the reference spot, and the measurement spot, thus obtaining high-precision optical axis alignment.

[0042] 2. In this invention, the real-time testing unit and the laser interferometric displacement measurement unit are independently distributed. The incident laser of the laser to be aligned and the incident laser of the dual-frequency laser both participate in the real-time testing unit. This enables the detection of the deviation between the reference spot and the measurement spot, thereby achieving universally adaptable optical axis alignment.

[0043] 3. This invention introduces interferometric displacement measurement technology into optical axis alignment to improve the optical axis alignment accuracy, enabling the device to perform optical axis alignment detection of stray light measurement systems in extremely weak stray light fields, extreme environment fields, and vacuum fields. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of an embodiment of a universally applicable high-precision laser measurement optical axis alignment device of the present invention;

[0045] Figure 2 This is a schematic diagram illustrating the principle of light spot alignment in an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram illustrating the principle of optical axis alignment angle deviation in an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram of the interference fringe spacing in an embodiment of the present invention.

[0048] Icon labels:

[0049] 1-Laser to be aligned, 2-Dual-frequency laser, 301-First beam splitter prism, 302-Second beam splitter prism, 303-Third beam splitter prism, 4-Reflection unit, 401-First reflector, 402-Second reflector, 5-Position detector, 6-Real-time test unit, 7-Laser interferometric displacement measurement unit, 8-Fiber optic coupler, 9-Receiver, 10-Acquisition card, 11-Host computer. Detailed Implementation

[0050] The technical solutions of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, what is described is only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] This invention provides a universal, high-precision laser measurement optical axis alignment device, such as... Figure 1As shown, the device includes a beam splitting system, a stray light measurement system, a laser interferometric displacement measurement system, and an optical axis alignment measurement system. The beam splitting system includes a first beam splitter 301, a second beam splitter 302, and a third beam splitter 303. The second beam splitter 302 has a beam splitting ratio of 1:1; the third beam splitter 303 has a beam splitting ratio of 1:9, with 90% transmission. The stray light measurement system includes a real-time testing unit 6, which is a laser energy and laser spot measurement system capable of measuring single laser propagation. The laser interferometric displacement measurement system includes a dual-frequency laser 2 and a laser interferometric displacement measurement unit 7. The dual-frequency laser 2 emits orthogonally polarized linearly polarized light with a wavelength stability range of ±2ppb. The optical axis alignment measurement system includes a reflection unit 4, a position detector 5, an optical fiber coupler 8, a receiver 9, a data acquisition card 10, and a host computer 11. The reflection unit 4 includes a first reflector 401 and a second reflector 402, the surface profile of which is less than λ / 10, where λ is the laser wavelength. The receiver 9 has a receiveable wavelength range of 300–1550 nm. The first beam splitter 301 is positioned between the laser to be aligned 1 and the real-time testing unit 6. The second beam splitter 302 and the third beam splitter 303 are sequentially positioned between the dual-frequency laser 2 and the laser interference displacement measurement unit 7, with the second beam splitter 302 located on the second reflected optical path of the first beam splitter 301. The position detector 5 is located on the first reflected optical path of the first beam splitter 301, and its output is connected to the input of the acquisition card 10. The fiber optic coupler 8 is located on the second reflected optical path of the third beam splitter 303, and its output is connected to the input of the acquisition card 10. The receiver 9 is located on the second reflected optical path of the second beam splitter 302, and its output is connected to the input of the acquisition card 10. The reflection unit 4 is positioned on the optical path between the first beam splitter 301 and the position detector 5. The first reflecting mirror 401 and the second reflecting mirror 402 included in the reflection unit 4 are arranged opposite to and parallel to each other, used to reflect the first reflected light from the first beam splitter 301 multiple times. The output of the acquisition card 10 is connected to the input of the host computer 11.

[0052] The laser to be aligned emits a laser beam, which is split by the first beam splitter 301. The first reflected light from the first beam splitter 301 is reflected multiple times by the first mirror 401 and the second mirror 402 and then incident on the position detector 5 to form a first reference spot. The first transmitted light from the first beam splitter 301 is incident on the alignment real-time test unit 6 for testing and then returns along the same path. It is then reflected by the first beam splitter 301 and transmitted by the second beam splitter 302 and incident on the receiver 9 to form a second reference spot.

[0053] The dual-frequency laser 2 emits a beam of orthogonally polarized linearly polarized light, which is split by the second beam splitter 302. The first transmitted light from the second beam splitter 302 is transmitted through the third beam splitter 303 and incident on the laser interference displacement measurement unit 7. Within the laser interference displacement measurement unit 7, a small displacement frequency shift signal and a displacement reference signal are formed, representing a displacement measurement step. The light returns along the same path and is split again by the third beam splitter 303. The second reflected light from the third beam splitter 303 is incident on the fiber coupler 8, where the fiber coupler 8 receives the first interference signal. The second transmitted light from the third beam splitter 303 is reflected by the second beam splitter 302, resulting in a second reflected light from the second beam splitter 302. The light incident on the receiver 9 forms a second interference signal; the first reflected light from the second beam splitter 302 is split by the first beam splitter 301 to form a third reflected light and a third transmitted light, i.e., the third reflected light and the third transmitted light from the first beam splitter 301; the third transmitted light from the first beam splitter 301 is reflected multiple times by the first reflector 401 and the second reflector 402 and incident on the position detector 5 to form a first measurement spot; the third reflected light from the first beam splitter 301 is incident on the real-time test unit 6 for testing, and then returns along the same path, carrying the error offset information of the real-time test unit 6. After being reflected by the first beam splitter 301 and transmitted by the second beam splitter 302, it is incident on the receiver 9 to obtain the second measurement spot;

[0054] like Figure 2 As shown, the first reference spot and the first measurement spot are simultaneously incident on the position detector 5. Based on the minimum resolution of the position detector 5, and using the first reference spot as a reference, the first measurement spot is adjusted to ensure that the first reference spot and the first measurement spot have an overlap S within a meter-level distance range. 重合 Greater than or equal to 85%

[0055]

[0056] In the formula: D1 is the radius of the first reference spot; θ1 is the angle between the center of the first reference spot and the center coincidence line; θ2 is the angle between the center of the first measurement spot and the center coincidence line; D2 is the radius of the first measurement spot. ΔL is the azimuth angle calculated using the first reference spot and the first measurement spot;

[0057] ΔL can be calculated based on the minimum resolution distance of position detector 5. The adjustment is repeated multiple times to achieve an overlap of 85% of the area between the two light spots.

[0058] like Figure 3As shown, the dual-frequency laser of the dual-frequency laser 2 and the laser of the laser to be aligned 1 are independent of each other; the laser to be aligned 1 emits laser, the laser is pre-modulated to the ideal position, and then the first beam splitter 301 is modulated to ensure that the second reflected light of the first beam splitter 301 can be received by the receiver 9. Then the position detector 5 is adjusted to ensure that the initial light spot of the laser to be aligned 1 is located at the center of the position detector 5, and then the laser to be aligned 1 is turned off.

[0059] Turn on the dual-frequency laser 2, and adjust the dual-frequency laser 2 according to the position of the first measurement spot of the position detector 5 to ensure that the first measurement spot can overlap with the preset position of the first reference spot by ≥85%.

[0060] By adjusting the laser interferometric displacement measurement unit 7, the second beam splitter 302 and the third beam splitter 303, the second measurement spot and the second interference signal can be obtained on the receiver 9, and the first interference signal can be received on the fiber optic coupler 8.

[0061] like Figure 4 As shown, the second measurement spot replaces the position information of the second reference spot. Based on the distance to the highest energy point of the receiver 9, the second reference spot and the second measurement spot are used as the optical axis error information values ​​of the real-time test unit 6 to be carried synchronously. The fiber optic coupler 8 detects the correspondence between the number of interference fringes moving m and the real-time displacement of the laser interference displacement measurement unit 7. At the same time, it detects the relationship between the number of second interference fringes (corresponding to the second interference information) moving in the receiver 9 and the position of the second measurement spot, and obtains the fringe movement of the second reference spot, the second measurement spot and the second interference fringes.

[0062] The first interference signal received on the fiber optic coupler 8 and the second interference signal received on the receiver 9 are completely consistent. When displacement occurs inside the laser interference displacement measurement unit 7, the fringes of the first interference signal move in real time. The relationship between the measured displacement ΔZ of the laser interference displacement measurement unit 7 and the number of interference fringes m can be obtained: ΔZ = mλ / 2. At the same time, the fringe movement of the second interference fringe can also be obtained. The fringe movement of the second interference fringe can be detected in real time by the displacement change of the laser interference displacement measurement unit 7. The detected displacement change value is the lateral offset of the second reference spot on the receiver 9 relative to the second interference signal at the cross center position of the photosensitive surface of the receiver 9 along the horizontal axis.

[0063] The second reference spot and the second measurement spot both contain the optical axis offset error of the real-time test unit 6. The second measurement spot is the measurement light of the real-time test unit 6, and it has a double spot structure with the preset center position of the second interference fringe. According to the change in the width and displacement of the interference fringe of the first interference signal, the optical axis deviation of the second measurement spot from the preset center position of the second interference fringe is detected. Taking the central optical axis of the normal of the photosensitive surface of the receiver 9 as the reference, the initial calculation surface distance between the perpendicular incident light rays of the photosensitive surface and the central axis of the second beam splitter (302) is Z, and the optical axis information formed by the spot formed by the second interference signal incident on the receiver 9 is α, which can be expressed as:

[0064] α = arctan(D3Z)

[0065] Wherein, the second measurement spot carrying the optical axis offset information of the real-time test unit 6 corresponds to the spot formed by the second interference signal, then the offset Δα of the optical axis between the real-time test unit (6) and the laser interference displacement measurement unit (7) can be expressed as:

[0066] Δα=arctan((D3+ΔZ)Z)-α

[0067] Where D3 is the spot radius of the second interference fringe, and Z is the perpendicular distance between the photosensitive surface of the receiver (9) and the central axis of the second beam splitter (302);

[0068] Based on the change in optical axis angle, the real-time test unit 6 and the first beam splitter 301 are finely adjusted to ensure that the second reference spot is finely adjusted to the preset center position of the second interference fringe, with an overlap of ≥85%, thus completing the optical axis alignment.

[0069] The optical axis alignment method provided by this invention mainly comprises three parts: pre-alignment, acquisition of the optical spot and scale, and fine alignment of the optical axis. A 632.8nm dual-frequency laser is used as the incident light. Part of the light is split by the second beam splitter 302, and the reflected light enters the real-time testing unit 6 to participate in the overall structure measurement, forming the second measurement spot. The transmitted light is incident on the pre-alignment measurement structure, achieving preliminary alignment between the laser 1 to be aligned and the dual-frequency laser 2 at the position detector 5. Another part of the light is incident on the laser interference displacement measurement unit 7 via the second beam splitter 302 and the third beam splitter 303 to obtain real-time step displacement measurement values. The interference displacement measurement information is split into two paths by the third beam splitter 303; one path is incident on the optical fiber coupling. Device 8 detects displacement measurement information to form a first interference signal; one path is incident on receiver 9 to form the spot and scale acquisition of real-time test unit 6, which is the second interference signal; the spot information acquired by receiver 9 includes: the second reference spot of real-time test unit 6 participated by laser 1 to be aligned during the pre-alignment stage, and the second measurement spot of real-time test unit 6 participated by dual-frequency laser 2; the spot information formed by the second interference fringes participating in the displacement stepping during the spot and scale acquisition stage. Taking the position of the spot formed by the second interference fringes as the standard position and the second measurement spot as the measurement position, the displacement of the interference fringes of the stepping displacement measurement spot is used to obtain the stepping displacement ΔL of the overlapping spot, realizing the detection of the spot divergence angle and the precise alignment of the optical axis. Due to its unique characteristics of separating the working wavelength and the detection wavelength, this device can not only be applied to the lens group measurement and focusing of lithography machines, projectors, etc., but also to the ultra-precise positioning measurement and extremely weak stray light detection of telescopes, crystal defects, etc., providing a new approach for the positioning and precise assembly of high-precision products.

[0070] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention should be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A universal, high-precision laser measurement optical axis alignment device for aligning the optical axis of a laser to be aligned (1) with a real-time testing unit (6); characterized in that: This includes a beam splitting system, a stray light measurement system, a laser interferometric displacement measurement system, and an optical axis alignment measurement system; The beam splitting system includes a first beam splitter (301), a second beam splitter (302), and a third beam splitter (303); The laser interferometric displacement measurement system includes a dual-frequency laser (2) and a laser interferometric displacement measurement unit (7); The optical axis alignment measurement system includes a position detector (5), an optical fiber coupler (8), a receiver (9), a data acquisition card (10), and a host computer (11); The first beam splitter (301) is disposed between the laser to be aligned (1) and the real-time test unit (6), and the first beam splitter (301) and the real-time test unit (6) are located sequentially on the first reflected light path of the second beam splitter (302); the second beam splitter (302) and the third beam splitter (303) are disposed sequentially between the dual-frequency laser (2) and the laser interference displacement measurement unit (7), and the second beam splitter (302) is located on the second reflected light path of the first beam splitter (301); The position detector (5) is located on the first reflected light path of the first beam splitter (301) and is used to obtain the first reference spot and the first measurement spot during pre-alignment. Its output end is connected to the input end of the acquisition card (10). The fiber optic coupler (8) is located on the second reflected light path of the third beam splitter (303) and is used to obtain the first interference signal during alignment. Its output end is connected to the input end of the acquisition card (10). The receiver (9) is located on the second reflected light path of the second beam splitter (302) and is used to obtain the second reference spot, the second interference signal, and the second measurement spot during pre-alignment. Its output end is connected to the input end of the acquisition card (10). The output terminal of the acquisition card (10) is connected to the input terminal of the host computer (11); The host computer (11) is used to calculate the azimuth angle information ΔL between the laser to be aligned (1) and the dual-frequency laser (2) based on the first reference spot and the first measurement spot, and to obtain the offset Δα between the optical axis of the real-time test unit (6) and the laser interference displacement measurement unit (7) based on the second reference spot and the second measurement spot, as well as the first interference signal and / or the second interference signal.

2. The universally applicable high-precision laser measurement optical axis alignment device according to claim 1, characterized in that: The optical axis alignment measurement system also includes a reflection unit (4) disposed in the optical path between the first beam splitter (301) and the position detector (5); The reflecting unit (4) includes a first reflecting mirror (401) and a second reflecting mirror (402); The first reflector (401) and the second reflector (402) are arranged opposite to each other and parallel to each other, and are used to reflect the first reflected light from the first beam splitter (301) multiple times.

3. The universally applicable high-precision laser measurement optical axis alignment device according to claim 2, characterized in that: The wavelength stability range of the dual-frequency laser (2) is ±2ppb.

4. The universally applicable high-precision laser measurement optical axis alignment device according to claim 3, characterized in that: The second beam splitter (302) has a beam splitting ratio of 1:1; The third beam splitter (303) has a beam splitting ratio of 1:9, of which 90% is transmitted light.

5. The universally applicable high-precision laser measurement optical axis alignment device according to claim 4, characterized in that: The surface shape of the first reflector (401) and the second reflector (402) is less than λ / 10, where λ is the laser wavelength.

6. The universally applicable high-precision laser measurement optical axis alignment device according to claim 5, characterized in that: The receiver (9) has a wavelength range of 300 to 1550 nm.

7. A universally applicable, high-precision laser measurement optical axis alignment method, characterized in that, Includes the following steps: Step 1: Construct a universal, high-precision laser measurement optical axis alignment device as described in any one of claims 1-6; Step 2: Turn on the laser to be aligned (1), and pre-align the laser to be aligned (1) with the real-time test unit (6). Then the position detector (5) obtains the first reference spot and the receiver (9) obtains the second reference spot. Make the first reference spot completely aligned with the center of the crosshair of the position detector (5). Step 3: Turn off the laser to be aligned (1) and turn on the dual-frequency laser (2). Then the position detector (5) obtains the first measurement spot, the fiber coupler (8) obtains the first interference signal, and the receiver (9) obtains the second interference signal and the second measurement spot. Step 4: The host computer (11) acquires the position information of the first reference spot and the first measurement spot through the acquisition card (10); and calculates the azimuth angle information ΔL between the laser to be aligned (1) and the dual-frequency laser (2) through the first reference spot and the first measurement spot. Step 5: Based on the azimuth angle information ΔL obtained in Step 4, adjust the pose of the dual-frequency laser (2) and the second beam splitter (302) so that the overlap of the position information of the first reference spot and the first measurement spot is greater than or equal to the preset value; synchronously adjust the pose of the laser interference displacement measurement unit (7) so that the spot of the second interference signal is located at the center of the optical axis of the photosensitive surface of the receiver (9). Step 6: The host computer (11) acquires the second reference spot, the second measurement spot, the first interference signal, and / or the second interference signal through the acquisition card (10), replaces the second reference spot with the second measurement spot, and calculates the angular offset α between the corresponding optical axes based on the second measurement spot and the second interference signal; and calculates the measurement displacement ΔZ and the number of interference fringes m of the laser interference displacement measurement unit (7) based on the first interference signal or the second interference signal, and then calculates the correspondence between the measurement displacement ΔZ and the number of interference fringes m: In the formula, λ is the laser wavelength; Step 7: Calculate the offset Δα of the optical axis between the real-time test unit (6) and the laser interferometric displacement measurement unit (7) based on the calculation results of Step 6: Δα=arctan((D3+ΔZ)Z)-α Wherein, D3 is the spot radius of the second reference spot or the second measurement spot, and Z is the vertical distance between the photosensitive surface of the receiver (9) and the central axis of the second beam splitter (302); Step 8: Adjust the real-time test unit (6) based on the offset Δα calculated in step 7, so that the second measurement spot received by the receiver (9) coincides with the second interference signal, and the alignment of the laser (1) to be aligned and the real-time test unit (6) is completed.

8. The universally applicable high-precision laser measurement optical axis alignment method according to claim 7, characterized in that: In step 5, the preset value is 85%.

9. The universally applicable high-precision laser measurement optical axis alignment method according to claim 8, characterized in that, In step 5, the overlap S between the first reference spot and the first measurement spot is calculated using the following formula. 重合 : In the formula: D1 is the radius of the first reference spot; θ1 is the change in the angle of the coincidence point of the first reference spot and the first measurement spot relative to the center of the first reference spot; θ2 is the change in the angle of the coincidence point of the first measurement spot and the first reference spot relative to the center of the first measurement spot; and D2 is the radius of the first measurement spot.

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