A laser focusing system, a laser welding system and a laser welding machine

Abstract

The application discloses a laser converging system, a laser welding system and a laser welding machine, and relates to the technical field of optical converging. The laser converging system converts the preset S polarization laser beams sent by a laser device into two S polarization beams, and then into two P polarization beams through a plane mirror, an S polarization beam splitter, a first controlled mirror and a second controlled mirror arranged in the same XY plane, and converges the first light path and the second light path corresponding to the two P polarization beams at a preset space point outside the XY plane, so that the imaging light path for observing the converging conditions of the P polarization beams is designed outside the XY plane where the laser transmission light path is located, the mutual interference between the laser transmission light path and the imaging light path is avoided, and the control precision of the laser convergence is improved.

Description

Technical Field

[0001] This application relates to the field of optical confocal technology, and in particular to a laser focusing system, a laser welding system, and a laser welding machine. Background Technology

[0002] To ensure the optical transmission efficiency and quality of the fiber array, a laser fusion splicer is typically used during the fabrication process to precisely fuse multiple fibers to a large end cap. Considering the precision required for laser fusion splicing, the machine is usually equipped with hardware devices to monitor laser power and focusing parameters at the splice point. These acquired parameters are then used for feedback control based on time or spatial dimensions, thereby improving the reliability and stability of the laser welding process.

[0003] In the optical path design of laser welding machines, to ensure the focusing accuracy and efficiency of each laser beam, the transmission optical paths for each laser beam are usually placed on the same plane, and the confocal point of each laser beam is located in the central region of the optical system. However, this design makes it difficult for the hardware device for observing the weld joint to be configured with an imaging optical path that can effectively observe the confocal point of each laser beam, which in turn affects the weld joint control effect.

[0004] When using an S-polarized laser source for welding, to ensure welding quality, the S-polarized laser needs to be converted into a P-polarized laser with higher transmittance before focusing. Because the laser transmission optical path design must meet the physical characteristics of both S-polarized and P-polarized laser transmission, the corresponding imaging optical path design becomes more difficult, making it harder to guarantee welding accuracy and increasing the conditions for successful welding, such as reducing the maximum diameter suitable for effective welding. Utility Model Content

[0005] The main objective of this application is to provide a laser focusing system, a laser welding system, and a laser welding machine, which aims to solve the technical problem of how to improve the control accuracy of laser focusing when using a light source that outputs S-polarized laser for laser focusing.

[0006] To achieve the above objectives, embodiments of this application provide a laser focusing system, which includes: a laser, a plane mirror, an S-polarization beam splitter, a first controlled mirror, and a second controlled mirror, all disposed in the XY plane;

[0007] The laser is used to emit a preset S-polarized laser beam to the plane mirror;

[0008] The plane mirror is used to reflect the received preset S-polarized laser beam to the S-polarized beam splitter;

[0009] The S-polarization beam splitter is used to transmit and reflect the received preset S-polarization laser beam, transmit the first S-polarization beam formed by transmission to the first controlled reflector, and transmit the second S-polarization beam formed by reflection to the second controlled reflector.

[0010] The first controlled reflector is equipped with a scanning galvanometer, which is used to convert the first S-polarized beam into a first P-polarized beam and form a first optical path through secondary reflection, and to adjust the spatial angle of the first optical path based on the control of the scanning galvanometer, and the optical path between the secondary reflections is parallel to the XY plane.

[0011] The second controlled reflector is equipped with a scanning galvanometer, which is used to convert the second S-polarized beam into a second P-polarized beam and form a second optical path through secondary reflection, and to adjust the spatial angle of the second optical path based on the control of the scanning galvanometer. The optical path between the secondary reflections is parallel to the XY plane.

[0012] The first optical path and the second optical path converge at a preset spatial point, which is located outside the XY plane.

[0013] In one embodiment, the laser focusing system further includes: a beam expander;

[0014] The beam expander is disposed between the laser and the plane mirror and is used to expand the spot diameter of the preset S-polarized laser beam to a preset diameter.

[0015] In one embodiment, the first controlled reflector includes: a first sub-reflector and a second sub-reflector;

[0016] The first sub-reflector is provided with a first scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the first sub-reflector; the second sub-reflector is provided with a second scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the second sub-reflector.

[0017] The first sub-reflector is used to reflect the first S-polarized beam at a spatial angle parallel to the XY plane to form the first P-polarized beam, and to transmit the first P-polarized beam to the second sub-reflector.

[0018] The second sub-reflector is used to reflect the first P-polarized beam to form a first optical path;

[0019] The spatial angle of the first optical path is controlled by the rotation angle of the first scanning mirror and the second scanning mirror.

[0020] In one embodiment, the second controlled reflector includes: a third sub-reflector and a fourth sub-reflector;

[0021] The third sub-reflector is equipped with a third scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the third sub-reflector; the fourth sub-reflector is equipped with a fourth scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the fourth sub-reflector.

[0022] The third sub-reflector is used to reflect the second S-polarized beam at a spatial angle parallel to the XY plane to form the second P-polarized beam, and to transmit the second P-polarized beam to the fourth sub-reflector.

[0023] The fourth sub-reflector is used to reflect the second P-polarized beam to form a second optical path;

[0024] The spatial angle of the second optical path is controlled by the rotation angle of the third scanning mirror and the fourth scanning mirror.

[0025] In one embodiment, the angle formed by the projection of the first optical path and the second optical path onto the XY plane is 90°.

[0026] In one embodiment, the first optical path makes an angle of 60° with respect to the vertical direction of the XY plane, and the second optical path makes an angle of 60° with respect to the vertical direction of the XY plane.

[0027] In one embodiment, at the preset spatial point, the optical power provided by the first optical path is equal to the optical power provided by the second optical path.

[0028] In one embodiment, the laser is a carbon dioxide laser, and the preset S-polarized laser beam is a linearly polarized laser.

[0029] To achieve the above objectives, this application also proposes a laser fusion welding system, which includes two laser focusing systems as described above;

[0030] The optical paths of the two laser converging systems are mirror-symmetrically arranged in the XY plane, so that the first and second optical paths formed by each laser converging system converge at the same preset spatial point; the lengths of each first and second optical path are the same; the optical power provided by each first optical path and the optical power provided by each second optical path received at the preset spatial point are the same; the projections of the transmission paths of each first and second optical path on the XY plane form a square diagonal distribution shape.

[0031] To achieve the above objectives, this application also proposes a laser fusion welding machine that employs the laser focusing system described above.

[0032] This application provides a laser focusing system, a laser fusion welding system, and a laser fusion welding machine. The laser focusing system includes a laser, a plane mirror, an S-polarization beam splitter, a first controlled mirror, and a second controlled mirror, all disposed in the XY plane. The laser emits a preset S-polarized laser beam to the plane mirror. The plane mirror reflects the received preset S-polarized laser beam to the S-polarization beam splitter. The S-polarization beam splitter transmits and reflects the received preset S-polarized laser beam, transmitting the first S-polarized beam formed by transmission to the first controlled mirror and the second S-polarized beam formed by reflection to the second controlled mirror. A controlled reflector, equipped with a scanning galvanometer, is used to convert the first S-polarized beam into a first P-polarized beam through secondary reflection to form a first optical path, and to adjust the spatial angle of the first optical path based on the control of the scanning galvanometer. The optical path between the secondary reflections is parallel to the XY plane. A second controlled reflector, equipped with a scanning galvanometer, is used to convert the second S-polarized beam into a second P-polarized beam through secondary reflection to form a second optical path, and to adjust the spatial angle of the second optical path based on the control of the scanning galvanometer. The optical path between the secondary reflections is parallel to the XY plane. The first optical path and the second optical path converge at a preset spatial point, which is located outside the XY plane. By using a plane mirror, an S-polarization beam splitter, a first controlled mirror, and a second controlled mirror all positioned in the same XY plane, the preset S-polarized laser beam emitted by the laser is first converted into two S-polarized beams, and then into two P-polarized beams. The first and second optical paths corresponding to the two P-polarized beams are then converged at a preset spatial point outside the XY plane. This facilitates the design of an imaging optical path outside the XY plane where the laser transmission optical path is located to observe the convergence of each P-polarized beam, avoiding mutual interference between the laser transmission optical path and the imaging optical path, thereby improving the control accuracy of the convergence of each laser beam. Attached Figure Description

[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0034] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 This is a schematic diagram of the structure of the laser focusing system according to Embodiment 1 of this application;

[0036] Figure 2 A front view of the structure provided for Embodiment 1 of the laser welding system of this application;

[0037] Figure 3 Left view of the structure provided for Embodiment 1 of the laser welding system of this application;

[0038] Figure 4 Right view of the structure provided for Embodiment 1 of the laser welding system of this application;

[0039] Figure 5 This is a top view of the structure provided in Embodiment 1 of the laser welding system of this application;

[0040] Figure 6 A bottom view of the structure provided for Embodiment 1 of the laser welding system of this application;

[0041] Figure 7 This is a schematic diagram of the overall structure of the laser welding system provided in Embodiment 1 of this application.

[0042] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0043] It should be understood that the specific embodiments described herein are merely illustrative of the technical solutions of this application and are not intended to limit this application.

[0044] To better understand the technical solution of this application, a detailed description will be provided below in conjunction with the accompanying drawings and specific implementation methods.

[0045] This application presents a laser focusing system according to a first embodiment. Please refer to [link / reference]. Figure 1 The laser focusing system includes: a laser 10, a plane mirror 20, an S-polarization beam splitter 30, a first controlled mirror 41, and a second controlled mirror 42, all disposed in the XY plane;

[0046] The laser 10 is used to emit a preset S-polarized laser beam to the plane mirror 20;

[0047] The plane mirror 20 is used to reflect the received preset S-polarized laser beam to the S-polarized beam splitter 30;

[0048] The S-polarization beam splitter 30 is used to transmit and reflect the received preset S-polarization laser beam, transmit the first S-polarization beam formed by transmission to the first controlled reflector 41, and transmit the second S-polarization beam formed by reflection to the second controlled reflector 42.

[0049] The first controlled reflector 41 is equipped with a scanning galvanometer, which is used to convert the first S-polarized beam into a first P-polarized beam and form a first optical path through secondary reflection, and adjust the spatial angle of the first optical path based on the control of the scanning galvanometer. The optical path between the secondary reflections is parallel to the XY plane.

[0050] The second controlled reflector 42 is equipped with a scanning galvanometer, which is used to convert the second S-polarized beam into a second P-polarized beam and form a second optical path through secondary reflection, and to adjust the spatial angle of the second optical path based on the control of the scanning galvanometer. The optical path between the secondary reflections is parallel to the XY plane.

[0051] The first optical path and the second optical path converge at a preset spatial point, which is located outside the XY plane.

[0052] It should be understood that, please refer to Figure 1 The XY plane refers to a plane defined in three-dimensional space, with the mutually perpendicular X and Y directions serving as two reference directions. Correspondingly, the direction perpendicular to the XY plane can be understood as the Z direction. In this embodiment, the laser 10 can be a light source positioned in the XY plane for outputting a preset S-polarized laser beam. The preset S-polarized laser beam can be a laser beam with specific optical parameters in an S-polarized state. Specifically, the laser 10 can be a semiconductor laser, a solid-state laser, or other types of lasers. The optical parameters of the output preset S-polarized laser beam can be controlled by adjusting its driving parameters. These driving parameters may include driving current intensity, driving current pulse width, pulse frequency, etc., while the corresponding optical parameters may include laser wavelength, beam divergence angle, spot size / shape, optical power, and optical power density, etc.

[0053] It should be noted that the plane mirror 20 is an optical device capable of specular reflection of laser light. In this embodiment, the plane mirror 20 is fixed in the XY plane and positioned in the output light path of the laser 10. It is used to change the spatial angle of the preset S-polarized laser beam in three-dimensional space, so as to meet the transmission characteristics of the preset S-polarized laser beam while minimizing the overall size of the optical system, and to ensure that the arrangement of some optical devices in the laser transmission system can meet the transmission requirements of S-polarized laser light.

[0054] As is readily understood, the S-polarization beam splitter 30 is an optical device used to distribute and correspondingly split the optical power of an S-polarized laser beam. It can equally divide the optical power of the preset S-polarized laser beam reflected by the plane mirror 20, thereby forming transmitted light with half the optical power and reflected light with half the optical power. The S-polarization beam splitter 30 is also disposed in the XY plane; it only distributes the optical power of the S-polarized light without changing the polarization state of the subsequently formed beam. In this embodiment, the transmitted light refers to the aforementioned first S-polarized beam, and the reflected light refers to the aforementioned second S-polarized beam.

[0055] It should be noted that the first controlled reflector 41 is an optical device capable of secondary reflection of S-polarized light. It contains a scanning galvanometer, which allows for adjustment of the spatial angles of the first and second reflections, thereby reflecting a first optical path with a variable polarization state (from S-polarized to P-polarized) and a variable spatial angle. Similarly, the second controlled reflector 42 is also an optical device capable of secondary reflection of S-polarized light. It contains a scanning galvanometer, which allows for adjustment of the spatial angles of the first and second reflections, thereby reflecting a second optical path with a variable polarization state (from S-polarized to P-polarized) and a variable spatial angle.

[0056] It is worth noting that in this embodiment, whether in the first controlled reflector 41 or the second controlled reflector 42, based on the internal hardware structure, the exit angle of the first reflected light is parallel to the Z direction (or can be understood as perpendicular to the XY plane), and the emitted light always falls on the hardware structure that performs the secondary reflection, thus forming a first or second optical path with a changing polarization state. The total optical path lengths of the first and second optical paths reaching the preset spatial point are equal, and their optical power at the preset spatial point is also equal.

[0057] In practical implementation, after the laser focusing system, which is located entirely in the XY plane, is powered on, the laser 10 begins to operate, thereby outputting a preset S-polarized laser beam with specific optical parameters. A plane mirror 20 is fixed in the optical path of the laser 10, reflecting the preset S-polarized laser beam at a spatial angle conforming to the transmission characteristics of S-polarized light onto the S-polarized beam splitter 30. Based on its own physical characteristics, the S-polarized beam splitter 30 performs power distribution and beam splitting on the received preset S-polarized laser beam, transmitting half of the optical power of the preset S-polarized laser beam to form a first S-polarized beam, while reflecting the other half of the optical power of the preset S-polarized laser beam to form a second S-polarized beam. The first controlled reflector 41, under the control of the scanning galvanometer, performs a secondary reflection of the first S-polarized beam, converting its polarization state from S-polarization to P-polarization to obtain a first P-polarized beam. The first P-polarized beam forms a first optical path corresponding to a spatial angle. Simultaneously, the second controlled reflector 42, under the control of the scanning galvanometer, performs a secondary reflection of the second S-polarized beam, converting its polarization state from S-polarization to P-polarization to obtain a second P-polarized beam. The second P-polarized beam forms a second optical path at another spatial angle. Ultimately, the first and second optical paths converge at a preset spatial point outside the XY plane.

[0058] With this design, the laser transmission optical path is basically set within the XY plane. Within the XY plane, it can convert a single pre-defined S-polarized laser beam output from laser 10 into two P-polarized beams to improve optical power transmission efficiency. However, the final convergence point of the two P-polarized beams is set at a pre-defined spatial point outside the XY plane. In this case, the imaging optical path used to observe the laser convergence effect can be set on a spatial plane parallel to the XY plane at the pre-defined spatial point. This ensures that the optical components and other hardware structures used in the imaging optical path and the laser transmission optical path do not interfere with each other, enabling real-time observation of the laser convergence effect at the pre-defined spatial point. This helps improve the overall system's control accuracy of laser convergence, thereby enhancing the system's operational stability and reliability.

[0059] Furthermore, in this embodiment, the laser focusing system further includes: a beam expander 50;

[0060] The beam expander 50 is disposed between the laser 10 and the plane mirror 20, and is used to expand the spot diameter of the preset S-polarized laser beam to a preset diameter.

[0061] It should be understood that, according to optical principles, the divergence angle of a light beam is directly proportional to its wavelength and inversely proportional to its spot diameter.

[0062] It is easy to understand that, in this embodiment, a beam expander 50 can be set at the exit port of the laser 10 to increase the spot diameter of the preset S-polarized laser beam by several times, so as to achieve the preset diameter theoretically required by the entire system, and reduce its divergence angle by several times. Ultimately, the laser beam can maintain a small spot size and high energy density after propagating a longer distance, so as to ensure that the laser focused at the preset spatial point has sufficient power or energy to complete the complete fusion work.

[0063] Furthermore, in this embodiment, the first controlled reflector 41 includes: a first sub-reflector 411 and a second sub-reflector 412;

[0064] The first sub-reflector 411 is provided with a first scanning galvanometer, the rotation axis of the first scanning galvanometer is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the first sub-reflector 411; the second sub-reflector 412 is provided with a second scanning galvanometer, the rotation axis of the second scanning galvanometer is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the second sub-reflector 412.

[0065] The first sub-reflector 411 is used to reflect the first S-polarized beam at a spatial angle parallel to the XY plane to form the first P-polarized beam, and to transmit the first P-polarized beam to the second sub-reflector 412.

[0066] The second sub-reflector 412 is used to reflect the first P-polarized beam to form a first optical path;

[0067] The spatial angle of the first optical path is controlled by the rotation angle of the first scanning mirror and the second scanning mirror.

[0068] It should be noted that, in this embodiment, the first sub-reflector 411 and the second sub-reflector 412 are used to reflect the first S-polarized beam twice. The incident and exit angles of the laser at the first sub-reflector 411 are controlled by the rotation angle of the first scanning galvanometer, and the incident and exit angles of the laser at the second sub-reflector 412 are controlled by the rotation angle of the second scanning galvanometer.

[0069] In the optical path formed by the above structure, the rotation axis of the first scanning galvanometer is set on the plane formed by the incident light and the outgoing light corresponding to the reflection point of the first sub-reflector 411. This causes the first sub-reflector 411 to reciprocate under the control of the first scanning galvanometer, and its outgoing light scans back and forth in the first sector plane. The first scanning galvanometer scans a straight line rather than an arc. The rotation axis of the second scanning galvanometer is set on the plane formed by the incident light and the outgoing light corresponding to the reflection point of the second sub-reflector 412. This causes the second sub-reflector 412 to reciprocate under the control of the second scanning galvanometer, and its outgoing light scans back and forth in the second sector plane. The second scanning galvanometer scans a straight line rather than an arc. Thus, when the first sub-reflector 411 rotates, the angle formed by the first optical path and the XY plane in the first preset direction can be controlled; and when the second sub-reflector 412 rotates, the angle formed by the first optical path and the XY plane in the second preset direction can be controlled. This allows adjustment of the spatial angle of the first optical path, thereby adjusting the spatial position of the preset spatial point formed by the actual convergence of the first and second optical paths. The first preset direction and the second preset direction are two directions that are perpendicular to each other in the XY plane.

[0070] It is worth noting that, in this embodiment, the laser emitted from the first sub-reflector 411 to the second sub-reflector 412 remains parallel to the XY plane, thereby causing the transmitted first S-polarized beam to become P-polarized after secondary reflection, forming a first P-polarized beam for continued transmission. In other words, the first sub-reflector 411 actually reflects the first S-polarized beam, while the second sub-reflector 412 reflects the first P-polarized beam.

[0071] Furthermore, in this embodiment, the second controlled reflector 42 includes: a third sub-reflector 421 and a fourth sub-reflector 422;

[0072] The third sub-reflector 421 is provided with a third scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the third sub-reflector 421; the fourth sub-reflector 422 is provided with a fourth scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the fourth sub-reflector 422.

[0073] The third sub-reflector 421 is used to reflect the second S-polarized beam at a spatial angle parallel to the XY plane to form the second P-polarized beam, and to transmit the second P-polarized beam to the fourth sub-reflector 422.

[0074] The fourth sub-reflector 422 is used to reflect the second P-polarized beam to form a second optical path;

[0075] The spatial angle of the second optical path is controlled by the rotation angle of the third scanning mirror and the fourth scanning mirror.

[0076] It is easy to understand that, similar to the case of the first controlled reflector 41 described above, in this embodiment, the third sub-reflector 421 and the fourth sub-reflector 422 are used to reflect the second S-polarized beam twice. The incident and exit angles of the laser at the third sub-reflector 421 are controlled by the rotation angle of the third scanning galvanometer, and the incident and exit angles of the laser at the fourth sub-reflector 422 are controlled by the rotation angle of the fourth scanning galvanometer.

[0077] In the optical path formed by the above structure, the rotation axis of the third scanning galvanometer is set on the plane formed by the incident light and the outgoing light corresponding to the reflection point of the third sub-reflector 421, so that the third sub-reflector 421 reciprocates under the control of the third scanning galvanometer, and its outgoing light scans back and forth in the third sector plane. The third scanning galvanometer scans a straight line instead of an arc. The rotation axis of the fourth scanning galvanometer is set on the plane formed by the incident light and the outgoing light corresponding to the reflection point of the fourth sub-reflector 422, so that the fourth sub-reflector 422 reciprocates under the control of the fourth scanning galvanometer, and its outgoing light scans back and forth in the fourth sector plane. The fourth scanning galvanometer scans a straight line instead of an arc. Thus, when the third sub-reflector 421 rotates, the angle formed by the second light path and the XY plane in the first preset direction can be controlled; and when the fourth sub-reflector 422 rotates, the angle formed by the second light path and the XY plane in the second preset direction can be controlled, thereby adjusting the spatial angle of the second light path, and thus adjusting the spatial position of the preset spatial point formed by the actual convergence with the first light path.

[0078] It is worth noting that in this embodiment, the laser emitted from the third sub-reflector 421 to the fourth sub-reflector 422 remains parallel to the XY plane, thereby causing the transmitted second S-polarized beam to become P-polarized after secondary reflection, forming a second P-polarized beam for continued transmission. In other words, the third sub-reflector 421 actually reflects the second S-polarized beam, while the fourth sub-reflector 422 reflects the second P-polarized beam.

[0079] Furthermore, in this embodiment, the angle formed by the projection of the first optical path and the second optical path onto the XY plane is 90°.

[0080] It should be noted that in this embodiment, other optical hardware structures with the same or different functions can also be set in the XY plane, so that the projections of the first optical path and the second optical path on the XY plane are set at 90°. This means that other hardware structures can be set in the other 270° area of ​​the XY plane, which is convenient for subsequent system function expansion or iterative upgrades.

[0081] Furthermore, in this embodiment, the first optical path makes an angle of 60° with respect to the vertical direction of the XY plane, and the second optical path makes an angle of 60° with respect to the vertical direction of the XY plane.

[0082] It should be noted that, in this embodiment, the angle between the first optical path and the second optical path and the perpendicular direction (Z direction) of the XY plane is 60°. This ensures that the preset spatial point formed by their convergence is sufficiently far from the XY plane, facilitating the setup of the imaging system. Furthermore, it also prevents the preset spatial point from being too far from the XY plane, thus ensuring the control accuracy of laser convergence and preventing excessive power attenuation during laser transmission.

[0083] Furthermore, in this embodiment, at the preset spatial point, the optical power provided by the first optical path is equal to the optical power provided by the second optical path.

[0084] It is easy to understand that in this embodiment, in the above optical structure, the S-polarization beam splitter 30 divides the optical power of the preset S-polarization laser beam emitted from the laser 10 into equal parts, thereby forming a first S-polarization beam and a second S-polarization beam with equal initial optical power. Based on the control of the first controlled reflector 41 and the second controlled reflector 42, the first S-polarization beam is converted into a first P-polarization beam and transmitted to a preset spatial point via a first optical path. Correspondingly, the second S-polarization beam is converted into a second P-polarization beam and transmitted to the preset spatial point via a second optical path. The optical path lengths of the two optical paths formed by the beam splitting to the preset spatial point are consistent, meaning that the degree of optical power attenuation during transmission remains the same. Therefore, at the preset spatial point, the optical power received by the first optical path remains the same as the optical power received by the second optical path.

[0085] Furthermore, in this embodiment, the laser 10 is a carbon dioxide laser 10, and the preset S-polarized laser beam is a linearly polarized laser.

[0086] It is easy to understand that in this embodiment, the laser 10 can specifically be a carbon dioxide laser 10, whose output preset S-polarized laser beam is a linearly polarized laser, and the installation direction of the laser 10 is such that the linearly polarized laser reaches the S-polarized beam splitter 30 at the incident angle of the S-polarized laser.

[0087] This application proposes a laser focusing system. The laser focusing system uses a plane mirror, an S-polarization beam splitter, a first controlled mirror, and a second controlled mirror arranged in the same XY plane to first convert a preset S-polarized laser beam emitted by a laser into two S-polarized beams, and then into two P-polarized beams. The first and second optical paths corresponding to the two P-polarized beams are then converged at a preset spatial point outside the XY plane. This facilitates the design of an imaging optical path outside the XY plane where the laser transmission optical path is located to observe the convergence of each P-polarized beam, avoiding mutual interference between the laser transmission optical path and the imaging optical path, thereby improving the control accuracy of the convergence of each laser beam.

[0088] Furthermore, to achieve the above objectives, this application also provides a laser fusion welding system, please refer to... Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 as well as Figure 7 The laser fusion system includes two laser focusing systems as described above.

[0089] The optical paths of the two laser converging systems are mirror-symmetrically arranged in the XY plane, so that the first and second optical paths formed by each laser converging system converge at the same preset spatial point; the lengths of each first and second optical path are the same; the optical power provided by each first optical path and the optical power provided by each second optical path received at the preset spatial point are the same; the projections of the transmission paths of each first and second optical path on the XY plane form a square diagonal distribution shape.

[0090] It should be noted that the preset spatial point can also be understood as the area to be heated (the fusion center area) in the laser fusion splicing system, used to fusion several optical fibers to the end cap. In this embodiment, the laser fusion splicing system can be specifically applied in a laser fusion splicer, including two laser focusing systems as described above. In each laser focusing system, the laser 10, beam expander 50, plane mirror 20, S-polarization beam splitter 30, first controlled mirror 41, and second controlled mirror 42 are all located in the XY plane, and the optical paths formed by the two systems are mirror-symmetrically arranged. This allows the first and second optical paths formed by one laser focusing system to converge with the first and second optical paths formed by the other laser focusing system at the same preset spatial point, thereby achieving essentially 360° (relative to the plane angle in the XY plane) laser focusing at the preset spatial point, enabling uniform fusion work at that location.

[0091] It is worth noting that, in this embodiment, for any single laser focusing system, the angle between the projections of the transmission paths of the first and second optical paths formed on the XY plane is 90°. For two laser focusing systems, the angle between the projections of the transmission paths of the two first optical paths formed on the XY plane is also 90°. This means that the projections of the two first and two second optical paths on the XY plane can form a diagonal distribution in a positive direction. This ensures that the optical path lengths of the two first and two second optical paths formed by the two laser focusing systems are the same, and the power attenuation during transmission is also the same. Simultaneously, the initial optical power of the preset S-polarized laser beams output by the lasers 10 of the two laser focusing systems should also remain the same. This ensures that the optical power received around the preset spatial point (relative to the plane angle in the XY plane) is the same, resulting in the same heating. This reduces the occurrence of welding misalignment due to uneven heat distribution during the welding process, thus improving welding accuracy. Furthermore, during the fusion process, since the preset spatial point is set far away from the XY plane, imaging optical paths for observing the convergence effect can be set around it (relative to the plane angle in the XY plane). These paths will not interfere with the laser imaging optical paths located in the XY plane, thereby improving the control accuracy of laser convergence and further enhancing the fusion accuracy.

[0092] It should be noted that, in this embodiment, although both lasers 10 used in the two laser focusing systems emit preset S-polarized laser beams, due to the presence of their respective internal first controlled reflector 41 and second controlled reflector 42, the two final output first optical paths transmit first P-polarized beams, and correspondingly, the two final output second optical paths transmit second P-polarized beams. In other words, the final fusion operation is still performed using P-polarized laser beams, which can improve the energy absorption rate at the preset spatial point, enhance the consistency of the fusion depth, reduce fusion defects, and improve fusion efficiency.

[0093] This application proposes a laser fusion splicing system. This system can split and convert the S-polarized laser beam outside the XY plane where the laser transmission path of the S-polarized laser emitted from the laser source is located, forming four P-polarized beams with the same optical power, and uniformly converging them at a preset spatial point. While ensuring more uniform optical power in all spatial directions at the preset spatial point, it also facilitates the setting of an imaging optical path around the preset spatial point for observing the laser focusing effect. This prevents the plane of the imaging optical path from interfering with the plane of the laser transmission optical path, thereby improving the control accuracy of laser focusing.

[0094] In addition, to achieve the above objectives, this application also provides a laser welding machine, which employs the laser welding system described above.

[0095] The laser fusion splicer provided in this application, employing the laser fusion splicing system described in the above embodiments, can also solve the technical problem of improving the control accuracy of laser focusing when using a light source that outputs S-polarized laser for laser focusing. Compared with the prior art, the beneficial effects of the laser fusion splicer provided in this application are the same as those of the laser fusion splicing system provided in the above embodiments, and other technical features in the laser fusion splicer are the same as those disclosed in the methods of the above embodiments, and will not be repeated here.

[0096] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent scope of this application.

Claims

1. A laser focusing system, characterized in that, The laser focusing system includes: a laser, a plane mirror, an S-polarization beam splitter, a first controlled mirror, and a second controlled mirror, all disposed in the XY plane; The laser is used to emit a preset S-polarized laser beam to the plane mirror; The plane mirror is used to reflect the received preset S-polarized laser beam to the S-polarized beam splitter; The S-polarization beam splitter is used to transmit and reflect the received preset S-polarization laser beam, transmit the first S-polarization beam formed by transmission to the first controlled reflector, and transmit the second S-polarization beam formed by reflection to the second controlled reflector. The first controlled reflector is equipped with a scanning galvanometer, which is used to convert the first S-polarized beam into a first P-polarized beam and form a first optical path through secondary reflection, and to adjust the spatial angle of the first optical path based on the control of the scanning galvanometer, and the optical path between the secondary reflections is parallel to the XY plane. The second controlled reflector is equipped with a scanning galvanometer, which is used to convert the second S-polarized beam into a second P-polarized beam and form a second optical path through secondary reflection, and to adjust the spatial angle of the second optical path based on the control of the scanning galvanometer. The optical path between the secondary reflections is parallel to the XY plane. The first optical path and the second optical path converge at a preset spatial point, which is located outside the XY plane.

2. The laser focusing system as described in claim 1, characterized in that, The laser focusing system also includes: a beam expander; The beam expander is disposed between the laser and the plane mirror and is used to expand the spot diameter of the preset S-polarized laser beam to a preset diameter.

3. The laser focusing system as described in claim 1, characterized in that, The first controlled reflector includes: a first sub-reflector and a second sub-reflector; The first sub-reflector is provided with a first scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the first sub-reflector; the second sub-reflector is provided with a second scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the second sub-reflector. The first sub-reflector is used to reflect the first S-polarized beam at a spatial angle parallel to the XY plane to form the first P-polarized beam, and to transmit the first P-polarized beam to the second sub-reflector. The second sub-reflector is used to reflect the first P-polarized beam to form a first optical path; The spatial angle of the first optical path is controlled by the rotation angle of the first scanning mirror and the second scanning mirror.

4. The laser focusing system as described in claim 1, characterized in that, The second controlled reflector includes: a third sub-reflector and a fourth sub-reflector; The third sub-reflector is equipped with a third scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the third sub-reflector; the fourth sub-reflector is equipped with a fourth scanning galvanometer, the rotation axis of which is perpendicular to the plane formed by the incident light and the outgoing light corresponding to the reflection point on the fourth sub-reflector. The third sub-reflector is used to reflect the second S-polarized beam at a spatial angle parallel to the XY plane to form the second P-polarized beam, and to transmit the second P-polarized beam to the fourth sub-reflector. The fourth sub-reflector is used to reflect the second P-polarized beam to form a second optical path; The spatial angle of the second optical path is controlled by the rotation angle of the third scanning mirror and the fourth scanning mirror.

5. The laser focusing system as described in claim 1, characterized in that, The angle formed by the projection of the first optical path and the second optical path onto the XY plane is 90°.

6. The laser focusing system as described in claim 1, characterized in that, The first optical path makes an angle of 60° with respect to the vertical direction of the XY plane, and the second optical path makes an angle of 60° with respect to the vertical direction of the XY plane.

7. The laser focusing system as described in claim 1, characterized in that, At the preset spatial point, the optical power provided by the first optical path is equal to the optical power provided by the second optical path.

8. The laser focusing system as described in claim 1, characterized in that, The laser is a carbon dioxide laser, and the preset S-polarized laser beam is a linearly polarized laser.

9. A laser fusion welding system, characterized in that, The laser welding system includes two laser focusing systems as described in any one of claims 1 to 8; The optical paths of the two laser converging systems are mirror-symmetrically arranged in the XY plane, so that the first and second optical paths formed by each laser converging system converge at the same preset spatial point; the lengths of each first and second optical path are the same; the optical power provided by each first optical path and the optical power provided by each second optical path received at the preset spatial point are the same; the projections of the transmission paths of each first and second optical path on the XY plane form a square diagonal distribution shape.

10. A laser welding machine, characterized in that, The laser welding machine uses the laser welding system as described in claim 9.

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