High-precision light receiving and transmitting optical path aligning and adjusting device

Abstract

The invention discloses a high-precision receiving and transmitting optical path alignment adjustment device, solves the problem of insufficient alignment precision of an optical axis of a transmitting optical path and an optical axis of a receiving optical system, and belongs to the technical field of laser radar receiving and transmitting optical systems. A high-precision receiving and transmitting optical path aligning and adjusting device comprises a signal laser, a signal light collimator, a reflector assembly, a reference laser, a reference light collimator, a four-dimensional adjusting frame and a receiving optical system. Laser emitted by a signal laser in the emission light path is collimated by a signal light collimator, and then is reflected by a reflector assembly placed in a right-angle manner to form an emission light beam; a reference laser and a reference light collimator in the receiving light path are mounted on a four-dimensional adjusting frame; reference light emitted by the reference laser forms a light beam with a certain divergence angle after passing through the reference light collimator, and then the light beam reaches the receiving optical system and returns again after being reflected by the receiving optical system. The whole light receiving and transmitting path aligning and adjusting device is simple in structural form and remarkable in effect.

Description

[0001] A high-precision optical path alignment and adjustment device Technical Field This invention relates to a high-precision optical path alignment and adjustment device, belonging to the technical field of lidar transceiver optical systems. Background Technology

[0002] In deep space exploration, lidar typically employs a coaxial transmit and receive optical path structure to achieve high-precision detection of the surface topography of extraterrestrial objects. Furthermore, to achieve a large entrance pupil diameter and strong stray light suppression capability, the receiving optical system has a small field of view, typically less than 1°. This places high demands on the alignment accuracy of the optical axes of the transmitting and receiving optical systems; if the direction of the transmitted beam deviates from the field of view of the receiving optical system, it will significantly reduce the energy reception efficiency of the receiving optical system, thereby affecting the measurement distance and accuracy. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and solve the problem of insufficient alignment accuracy between the optical axis of the transmitting optical path and the optical axis of the receiving optical system.

[0004] The objective of this invention is achieved through the following technical solutions: A high-precision optical path alignment and adjustment device includes a signal laser, a signal light collimator, a mirror assembly, a reference laser, a reference light collimator, a four-dimensional adjustment frame, and a receiving optical system; The signal laser, signal collimator, and mirror assembly form the transmitting optical path; the reference laser, reference collimator, four-dimensional adjustment frame, and receiving optical system form the receiving optical path. In the transmitting optical path, the laser emitted by the signal laser is collimated by the signal light collimator, and then reflected by the reflector assembly placed at an angle to form the emitted beam; In the receiving optical path, the reference laser and the reference collimator are mounted on a four-dimensional adjustment frame. The reference light emitted from the reference laser forms a beam with a certain divergence angle after passing through the reference collimator, and then reaches the receiving optical system. After being reflected by the receiving optical system, it returns.

[0005] Compared with the prior art, the present invention has the following advantages: (1) The present invention uses the self-collimation characteristic of the visible reference laser to obtain the optical axis of the receiving optical system. The reflected optical axis can be adjusted by adjusting the direction of the 45-degree reflector, so that the transmitting optical axis and the receiving optical axis are coaxial. Using this method, the transmitting optical axis and the receiving optical axis can be aligned at different angles to meet the requirements of long-distance measurement.

[0006] (2) The present invention obtains the optical axis of the receiving optical system through the self-collimation characteristics of the visible reference laser, thereby realizing the visualization of the virtual optical axis and making it more convenient to adjust.

[0007] (3) The present invention can adjust the reflected optical axis by adjusting the direction of the 45-degree reflector. The reflector is fixed with elastic silicone rubber, and its angle can be finely adjusted during the curing process of the silicone rubber.

[0008] (4) The entire light receiving and luminous path alignment and adjustment device of the present invention has a simple structure and significant effect. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of the high-precision optical path alignment and adjustment device of the present invention. Detailed Implementation

[0010] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0011] A high-precision optical path alignment and adjustment device, such as Figure 1 As shown, it includes a signal laser 1, a signal light collimator 2, a mirror assembly 3, a reference laser 4, a reference light collimator 5, a four-dimensional adjustment frame 6, and a receiving optical system 7. The signal laser 1, signal light collimator 2, and mirror assembly 3 form the transmitting optical path; the reference laser 4, reference light collimator 5, four-dimensional adjustment frame 6, and receiving optical system 7 form the receiving optical path.

[0012] The laser emitted by the signal laser 1 in the emission optical path is collimated by the signal light collimator 2, and then reflected by the reflector assembly 3 placed at 45 degrees to form the emission beam.

[0013] In the receiving optical path, the reference laser 4 and the reference collimator 5 are mounted on the four-dimensional adjustment frame 6. The reference light emitted from the reference laser 4 forms a beam with a certain divergence angle after passing through the reference collimator 5, and then reaches the receiving optical system 7, and returns after being reflected by the receiving optical system 7.

[0014] By adjusting the four-dimensional adjustment frame 6, the returned beam can be made to completely coincide with the output port of the reference laser 5. By adjusting the angle of the reflector assembly 3, the signal beam can also be made to completely coincide with the output port of the reference laser 5. At this time, the line connecting the center of the entrance of the receiving optical system 7 and the center of the output port of the reference laser 5 is simultaneously the optical axis of the receiving optical path and the optical axis of the transmitting optical path, thereby achieving high-precision alignment of the transmitting and receiving optical paths.

[0015] Preferably, the wavelength of the signal laser emitted by signal laser 1 is... The reference laser wavelength emitted by reference laser 5 is The signal laser wavelength is and the reference laser wavelength is They are not the same, and the reference laser is a visible laser.

[0016] Preferably, the signal light collimator 2 performs constant collimation on the signal light emitted from the signal laser 1, that is, the focal length of the signal light collimator 2 is not adjustable.

[0017] Preferably, the reflector assembly 3 is placed at 45°; its center is aligned with the center of the receiving optical system 7 through the structural shaft hole; the reflector of the reflector assembly 3 is fixed with elastic silicone rubber, and its angle can be finely adjusted during the curing process of the silicone rubber.

[0018] Preferably, both the reference laser 4 and the reference collimator 5 are mounted and fixed on the four-dimensional adjustment frame 6, and there are no requirements for the installation and fixing accuracy. The emission direction of the reference laser in four dimensions—up / down, left / right, pitch, and yaw—can be adjusted through the four-dimensional adjustment frame.

[0019] Preferably, the reference collimator 5 dynamically collimates the signal light emitted from the reference laser 4, meaning the focal length of the reference collimator 5 is adjustable. After collimation adjustment, the diameter of the reference laser beam reaching the entrance of the receiving optical system 7 has an error of no more than 5 mm with the aperture of the receiving optical system 7.

[0020] Preferably, the front end of the receiving optical system 7 includes a filter that can transmit signal laser and reflect reference laser, and the parallelism between the normal of the filter and the optical axis of the receiving optical system 7 is no greater than 30″.

[0021] Example: like Figure 1 As shown, a high-precision optical path alignment and adjustment device includes a signal laser 1, a signal collimator 2, a mirror assembly 3, a reference laser 4, a reference collimator 5, a four-dimensional adjustment frame 6, and a receiving optical system 7. The signal laser 1, signal collimator 2, and mirror assembly 3 form the transmitting optical path; the reference laser 4, reference collimator 5, four-dimensional adjustment frame 6, and receiving optical system 7 form the receiving optical path.

[0022] The laser emitted by the signal laser 1 in the emission optical path is collimated by the signal light collimator 2, and then reflected by the reflector assembly 3 placed at 45 degrees to form the emission beam.

[0023] In the receiving optical path, the reference laser 4 and the reference collimator 5 are mounted on the four-dimensional adjustment frame 6. The reference light emitted from the reference laser 4 forms a beam with a certain divergence angle after passing through the reference collimator 5, and then reaches the receiving optical system 7, and returns after being reflected by the receiving optical system 7.

[0024] By adjusting the four-dimensional adjustment frame 6, the returned beam can be made to perfectly coincide with the output port of the reference laser 5. By adjusting the angle of the reflector, the signal beam can also be made to perfectly coincide with the output port of the reference laser 5. At this time, the line connecting the center of the entrance of the receiving optical system 7 and the center of the output port of the reference laser 5 is simultaneously the optical axis of both the receiving optical path and the transmitting optical path, thereby achieving high-precision alignment of the transmitting and receiving optical paths.

[0025] The signal laser is a near-infrared laser with a center wavelength of 1064 nm. The signal collimator is a fixed-focus optical system. The beam diameter and divergence angle of the signal laser after passing through the signal collimator are 10 mm and 0.2 mrad, respectively.

[0026] The reflector assembly includes a reflector and its mounting structure. The reflector assembly and the receiving optical system are mounted via a structural shaft hole, ensuring that the offset between the reflector center and the optical system center does not exceed 20µm. The reflector and its mounting structure are secured with elastic silicone rubber.

[0027] The reference laser is a visible green laser with a center wavelength of 532 nm. The reference collimator is a 10x zoom optical system. The divergence angle of the reference laser after passing through the reference collimator ranges from 0.2 mrad to 2 mrad.

[0028] Both the reference laser and the reference collimator are fixed to the four-dimensional adjustment frame with screws. The four-dimensional adjustment frame can adjust four dimensions: up / down, left / right, pitch, and yaw.

[0029] The front end of the receiving optical system includes a filter with an effective aperture of 40 mm, which transmits 1064 nm and reflects 532 nm. The angle between the filter and the optical axis of the receiving optical system is less than 30″. The distance between the receiving optical system and the reference laser is approximately 50 m.

[0030] The specific assembly and adjustment steps are as follows: (1) Adjust the four dimensions of the four-dimensional adjustment frame, namely up and down, left and right, pitch and yaw, so that the outgoing reference 532nm laser shines on the receiving optical filter.

[0031] (2) Adjust the focal length of the reference collimator so that the diameter of the reference laser is about 40 mm and the size deviation from the filter is no more than 5 mm.

[0032] (3) Continue to adjust the four dimensions of the four-dimensional adjustment frame: up and down, left and right, pitch and yaw, so that the 532nm laser returned by the filter shines on the output port of the reference laser, with a deviation of no more than 10mm.

[0033] (4) Fix the reflector with silicone rubber and its fixing structure, and adjust the pitch and yaw direction of the reflector so that the 1064nm signal light shines on the output port of the reference laser with a deviation of no more than 10mm.

[0034] The above method completes the alignment of the optical axis of the 1064nm emitted laser and the optical axis of the receiving optical system. Considering the alignment error, the alignment accuracy of the receiving and emitting optical axes is approximately 0.7′.

[0035] The contents not described in detail in this specification are common knowledge to those skilled in the art.

[0036] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A high-precision optical path alignment and adjustment device, characterized in that, Includes a signal laser (1), a signal light collimator (2), a mirror assembly (3), a reference laser (4), a reference light collimator (5), a four-dimensional adjustment frame (6), and a receiving optical system (7); The signal laser (1), signal collimator (2), and mirror assembly (3) form the transmitting optical path; the reference laser (4), reference collimator (5), four-dimensional adjustment frame (6), and receiving optical system (7) form the receiving optical path. The laser emitted by the signal laser (1) in the emission optical path is collimated by the signal light collimator (2), and then reflected by the reflector assembly (3) placed at 45 degrees to form the emission beam; In the receiving optical path, the reference laser (4) and the reference collimator (5) are mounted on the four-dimensional adjustment frame (6); the reference light emitted from the reference laser (4) forms a beam with a certain divergence angle after passing through the reference collimator (5), and then reaches the receiving optical system (7), and returns after being reflected by the receiving optical system (7).

2. The high-precision optical path alignment and adjustment device according to claim 1, characterized in that, By adjusting the four-dimensional adjustment frame (6), the returned beam and the output port of the reference laser (5) can be made to completely overlap.

3. The high-precision optical path alignment and adjustment device according to claim 2, characterized in that, By adjusting the angle of the reflector assembly (3), the signal beam can be made to completely overlap with the output port of the reference laser (5).

4. The high-precision optical path alignment and adjustment device according to claim 3, characterized in that, The line connecting the center of the entrance of the receiving optical system (7) and the center of the output port of the reference laser (5) is simultaneously the optical axis of the receiving optical path and the optical axis of the transmitting optical path, thereby achieving high-precision alignment of the transmitting optical path and the receiving optical path.

5. The high-precision optical path alignment and adjustment device according to claim 1, characterized in that, The wavelength of the signal laser emitted by the signal laser (1) is different from the wavelength of the reference laser emitted by the reference laser (5), and the reference laser is a visible laser.

6. The high-precision optical path alignment and adjustment device according to claim 1, characterized in that, The signal light collimator (2) performs constant collimation on the signal light emitted from the signal laser (1).

7. The high-precision optical path alignment and adjustment device according to claim 1, characterized in that, The reflector of the reflector assembly (3) is fixed with elastic silicone rubber, and the angle of the reflector can be finely adjusted during the curing process of the silicone rubber.

8. The high-precision optical path alignment and adjustment device according to claim 1, characterized in that, The emission direction of the reference laser in four dimensions—up / down, left / right, pitch, and yaw—can be adjusted using the four-dimensional adjustment frame (6).

9. The high-precision optical path alignment and adjustment device according to claim 1, characterized in that, The reference collimator (5) dynamically collimates the signal light emitted from the reference laser (4).

10. The high-precision optical path alignment and adjustment device according to claim 1, characterized in that, Preferably, the front end of the receiving optical system (7) includes a filter that can transmit signal laser and reflect reference laser.

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