laser

Abstract

The application discloses a laser, and belongs to the technical field of photoelectricity. The laser comprises a tube shell, an opening is formed in one side of the tube shell; a plurality of light-emitting assemblies are arranged in the tube shell; a light-transmitting sealing assembly is arranged on the side of the opening of the tube shell; and a collimating mirror group is arranged on the side, away from the tube shell, of the light-transmitting sealing assembly. The collimating mirror group comprises a plurality of collimating lenses corresponding to the plurality of light-emitting assemblies one by one, each light-emitting assembly is used for emitting laser to the corresponding collimating lens, the collimating lens is used for reducing the divergence angle of the incident laser, and the reduction of the divergence angle of the laser on the slow axis is less than the reduction of the divergence angle on the fast axis. The application solves the problem that the laser emitted by the laser has poor collimation. The application is used for light emission.

Description

[0001] This application claims priority to Chinese Patent Application No. 202010965060.2, filed on September 15, 2020, entitled "Laser", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of optoelectronic technology, and in particular to a laser. Background Technology

[0003] With the development of optoelectronic technology, lasers are being widely used.

[0004] In related technologies, such as Figure 1 As shown, the laser 00 includes a housing 001, multiple light-emitting components 002, an annular sealing cover 003, a light-transmitting sealing layer 004, and a collimating lens assembly 005. One side of the housing 001 has an opening, and the multiple light-emitting components 002 are located within the housing 001's accommodating space. The outer edge of the sealing cover 003 is fixed to the side of the housing 001 with the opening. The edge of the light-transmitting sealing layer 004 is fixed to the inner edge of the sealing cover 003. The edge of the collimating lens assembly 005 is fixed to the outer edge of the sealing cover 003 on the surface away from the housing 001. The side of the collimating lens assembly 005 near the sealing cover 003 is flat, while the side away from the sealing cover 003 includes multiple convex arc surfaces corresponding one-to-one with the multiple light-emitting components 002. Each convex arc surface can be a portion of a sphere. In the collimating lens group 005, each convex arc surface can be used as a collimating lens T. Each light-emitting component 002 emits laser light into the corresponding collimating lens T, which is used to collimate the incident laser light before emitting it.

[0005] However, the collimating lens in the relevant technology has a poor collimation effect on lasers. Summary of the Invention

[0006] This application provides a laser that solves the problem of poor collimation of the emitted laser light. The laser includes:

[0007] A tubular shell, one side of which has an opening;

[0008] Multiple light-emitting components are located in the accommodating space of the tube shell;

[0009] A light-transmitting sealing assembly is located on the side of the opening of the tube shell;

[0010] The collimating lens assembly is located on the side of the light-transmitting sealing assembly away from the tube shell;

[0011] A collimating lens assembly, the edge of which is fixed to the outer edge of the sealing cover plate away from the surface of the base plate;

[0012] The collimating lens group includes multiple collimating lenses that correspond one-to-one with the multiple light-emitting components. Each light-emitting component is used to emit laser light to the corresponding collimating lens. The collimating lens is used to reduce the divergence angle of the incident laser light, and to make the reduction in the divergence angle of the laser light on the slow axis less than the reduction in the divergence angle on the fast axis.

[0013] The beneficial effects of the technical solution provided in this application include at least the following:

[0014] In the laser provided in this application, after each light-emitting component emits laser light to its corresponding collimating lens, the collimating lens can reduce the divergence angle of the laser light to collimate it. Since the divergence angle of the laser light on the fast axis is greater than that on the slow axis, and in related technologies, each convex surface in the collimating lens group is a part of a sphere, the collimation effect of each convex surface on both the fast and slow axes is the same, resulting in a significant difference in the divergence angle of the laser light passing through the collimating lens between the fast and slow axes. However, in the embodiment of this application, the collimating lens can reduce the decrease in the divergence angle on the slow axis after passing through the collimating lens compared to the decrease in the divergence angle on the fast axis. Therefore, in this application, the difference in the divergence angle between the fast and slow axes can be reduced after the laser light passes through the collimating lens, improving the overall collimation effect of the laser light emitted by the laser. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a laser provided by related technologies;

[0017] Figure 2 This is a schematic diagram of the structure of a laser provided in an embodiment of this application;

[0018] Figure 3 This is a schematic diagram of the structure of a collimating lens provided in an embodiment of this application;

[0019] Figure 4 This is a schematic diagram of another collimating lens provided in an embodiment of this application;

[0020] Figure 5 This is a schematic diagram of another collimating lens provided in an embodiment of this application;

[0021] Figure 6 This is a schematic diagram of another collimating lens provided in the embodiments of this application;

[0022] Figure 7 This is a schematic diagram of the structure of a collimating lens provided in another embodiment of this application;

[0023] Figure 8 This is a schematic diagram of another collimating lens provided in another embodiment of this application;

[0024] Figure 9 This is a schematic diagram of a collimating lens assembly provided in an embodiment of this application;

[0025] Figure 10 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application;

[0026] Figure 11 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application;

[0027] Figure 12 This is a schematic diagram of another collimating lens assembly provided in the embodiments of this application;

[0028] Figure 13 This is a schematic diagram of another laser structure provided in an embodiment of this application;

[0029] Figure 14 This is a schematic diagram of another laser provided in the embodiments of this application. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0031] With the development of optoelectronic technology, lasers are being used more and more widely. For example, lasers can be used in welding and cutting processes, which require the laser to emit high-energy laser beams. The collimation effect of the emitted laser has a significant impact on the laser energy; the better the collimation effect, the higher the energy. Lasers can also be used as a light source in laser projection or laser television. In this case, the collimation effect of the emitted laser has a significant impact on its brightness; the better the collimation effect, the higher the brightness, and consequently, the better the display effect of the image formed by the laser. The following embodiments of this application provide a laser that can improve the collimation of the emitted laser beam.

[0032] Figure 2 This is a schematic diagram of the structure of a laser provided in an embodiment of this application. Figure 2 As shown, the laser 10 may include: a housing 101, multiple light-emitting components 102, a light-transmitting and sealing assembly (such as including a sealing cover plate 103 and a light-transmitting and sealing layer 104), and a collimating lens group 105. The light-transmitting and sealing assembly may also be referred to as an upper cover assembly.

[0033] One side of the housing 101 has an opening, which encloses an accommodating space in which the plurality of light-emitting components 102 are located. A light-transmitting sealing assembly is located on the side of the opening of the housing 101, and a collimating lens assembly 105 is located on the side of the light-transmitting sealing assembly away from the housing 101. Optionally, the sealing cover 103 in the light-transmitting sealing assembly is annular, and the outer edge of the sealing cover 103 is fixed to the side of the opening of the housing 101. The edge of the light-transmitting sealing layer 104 is fixed to the inner edge of the sealing cover 103. The edge of the collimating lens assembly 105 is fixed to the outer edge of the sealing cover 103 on the surface away from the housing 101. Optionally, the edge of the collimating lens assembly 105 can be bonded to the outer edge of the sealing cover 103 using an adhesive, which may include glass melt adhesive, low-temperature glass solder, epoxy resin, or other adhesives.

[0034] The collimating lens group 105 includes multiple collimating lenses T corresponding one-to-one with the plurality of light-emitting components 102. Each light-emitting component 102 emits laser light into its corresponding collimating lens T, and the collimating lens T collimates the incident laser light. It should be noted that collimating light means adjusting the divergence angle of the light rays to make them as close as possible to parallel light. The collimating lens T can reduce the divergence angle of the incident laser light, and the reduction in the divergence angle on the slow axis is less than the reduction in the divergence angle on the fast axis. That is, the collimating effect of the collimating lens on the slow axis is weaker than its collimating effect on the fast axis. For example, the slow axis of the laser light incident on the collimating lens T is parallel to... Figure 2 In the x-direction, the fast axis of the laser is parallel to... Figure 2 The direction perpendicular to the plane of the paper. Optionally, the collimating lens can be made of glass.

[0035] It should be noted that the divergence angle of the laser emitted by the light-emitting component on the fast axis is greater than that on the slow axis, and the difference between the divergence angles on the fast and slow axes is significant. The fast and slow axes represent the directions of two light vectors during light transmission, with the fast axis perpendicular to the slow axis. For example, the divergence angle of the laser emitted by the light-emitting component on the fast axis ranges from 25 degrees to 35 degrees (e.g., 30 degrees), while the divergence angle on the slow axis ranges from 5 degrees to 7 degrees (e.g., 7 degrees). In related technologies, the collimating lens in a collimating lens assembly includes two opposing surfaces. To improve the production efficiency or ease of installation of the collimating lens assembly, one of these surfaces is set as a plane, and the other is set as a convex arc surface with the same curvature in all directions. The collimating lens can collimate the incident laser through the action of this convex arc surface. In related technologies, the convex arc surface is a part of a sphere, and the curvature in all directions of the convex arc surface is equal. Therefore, the convex arc surface reduces the divergence angle to the same extent on both the fast and slow axes of the incident laser. The difference in the divergence angle of the laser passing through the collimating lens on the fast and slow axes is still relatively large, resulting in poor collimation of the laser emitted by the laser.

[0036] In the laser provided in this application embodiment, each collimating lens in the collimating lens group reduces the divergence angle of the incident laser on the slow axis by less than the reduction in the divergence angle on the fast axis. In other words, the collimating lens's collimation effect on the laser on the slow axis is weaker than its collimation effect on the fast axis. Since the divergence angle of the laser incident on the collimating lens on the fast axis is greater than that on the slow axis, the difference in divergence angles between the fast and slow axes can be reduced after the laser passes through the collimating lens, thus improving the overall collimation effect of the laser emitted by the laser.

[0037] In summary, in the laser provided in this application embodiment, after each light-emitting component emits laser light to the corresponding collimating lens, the collimating lens can reduce the divergence angle of the laser light to collimate it. Since the divergence angle of the laser light on the fast axis is greater than that on the slow axis, the collimating lens in this application embodiment can ensure that the reduction in the divergence angle on the slow axis after passing through the collimating lens is less than the reduction in the divergence angle on the fast axis. Therefore, in this application, the difference in divergence angle between the fast and slow axes can be reduced after the laser light passes through the collimating lens, improving the overall collimation effect of the laser light emitted by the laser.

[0038] Please continue to refer to this. Figure 2The collimating lens T has a first surface D1 and a second surface D2, which are two opposing surfaces of the collimating lens, with the first surface D1 closer to the housing 101 than the second surface D2. The laser emitted by the light-emitting component 102 passes through the light-transmitting sealing layer 104 and is directed towards the corresponding collimating lens T, entering the collimating lens T through its first surface D1; it then propagates within the collimating lens T and exits through its second surface D2. The first surface D1 is the incident light surface of the collimating lens T, and the second surface D2 is the exit light surface. The collimating lens T's ability to adjust the divergence angle and transmission direction of the incident laser can be determined by the curvature of the first surface D1 and the second surface D2. Different curvatures of the first surface D1 and the second surface D2 will result in different shapes for the collimating lens.

[0039] In this embodiment, the collimating lens in the collimating lens group can be implemented in various ways to ensure that the reduction in the divergence angle of the incident laser on the slow axis is less than the reduction in the divergence angle on the fast axis, so as to minimize the difference in the divergence angle of the laser emitted from the collimating lens on the fast and slow axes and improve the collimation of the laser. Two of these implementation methods are explained below as examples.

[0040] In the first alternative implementation of the collimating lens, the first surface D1 of the collimating lens T is used to expand the divergence angle of the incident laser on the slow axis; the second surface D2 is used to reduce the divergence angle of the incident laser on both the fast axis and the slow axis.

[0041] Figure 3 This is a schematic diagram of the structure of a collimating lens provided in an embodiment of this application. Figure 4 This is a schematic diagram of another collimating lens provided in an embodiment of this application. Figure 4 It can be Figure 3 A top view of the laser shown. Figure 3 and Figure 4 As shown, the collimating lens T is cylindrical. Its first surface D1 includes a concave arc surface, which expands the divergence angle of the laser beam on the slow axis. The second surface D2 includes a convex arc surface, which reduces the divergence angle of the incident laser beam on both the fast and slow axes. Both the first surface D1 and the second surface D2 can achieve this adjustment of the laser divergence angle in various ways.

[0042] In the first optional implementation of D1 on the first surface, please combine... Figure 3 and Figure 4The concave surface in the first surface D1 has curvature on both the slow axis (x-direction) and the fast axis (y-direction) of the incident laser, and the radius of curvature of the concave surface on the slow axis is smaller than that on the fast axis. Since the curvature of a curved surface is the reciprocal of its radius of curvature, the curvature of the concave surface in the first surface D1 on the slow axis of the incident laser is greater than its curvature on the fast axis, and the curvature of the concave surface on the slow axis is greater than that on the fast axis. A surface with different radii of curvature in different directions can also be called a freeform surface; this convex surface can be similar to a portion of the surface of a rugby ball.

[0043] It should be noted that the concave surface of the lens has a diffusing effect on the incident light. The larger the radius of curvature of the concave surface, the smaller its curvature, and consequently, the weaker its diffusing effect on the light, resulting in a smaller diffusion of the light's divergence angle. In the embodiments of this application, the radius of curvature of the concave surface of the collimating lens on the slow axis of the incident laser is smaller than its radius of curvature on the fast axis. Therefore, after the laser emitted by the light-emitting component passes through the concave surface of the collimating lens, the increase in the divergence angle of the laser on the fast axis is less than the increase in the divergence angle on the slow axis. Since the original divergence angle of the laser emitted by the light-emitting component on the fast axis is greater than its divergence angle on the slow axis, the difference between the divergence angle on the slow axis and the divergence angle on the fast axis after passing through the concave surface of the collimating lens is relatively small. Compared to the divergence angle after entering the collimating lens in the prior art, in the embodiments of this application, after the laser passes through the concave arc surface, the divergence angle of the laser on the fast axis can be increased by 1.1 degrees to 1.5 degrees, and the divergence angle of the laser on the slow axis can be increased by 1.5 degrees to 2.5 degrees, thus reducing the angle difference between the laser on the fast axis and the slow axis.

[0044] Figure 3 and Figure 4 Taking a collimating lens T with its first surface D1 being a concave arc surface and its second surface D2 being a convex arc surface (i.e., the concave arc surface encompassing the entire area of ​​the first surface D1 and the convex arc surface encompassing the entire area of ​​the second surface D2) as an example, optionally... Figure 5 This is a schematic diagram of another collimating lens provided in an embodiment of this application. For example... Figure 5 As shown, only a portion of the first surface D1 can be a concave arc surface. Alternatively, only a portion of the second surface D2 can be a convex arc surface. The laser can be directed only to a portion of the first surface D1 and exit from a portion of the second surface D2; the portion of the first surface D1 to which the laser is directed can be a concave arc surface, and the portion of the second surface D2 from which the laser exits can be a convex arc surface.

[0045] In the second alternative implementation of the first surface D1 Figure 6 This is a schematic diagram of another collimating lens provided in the embodiments of this application. Figure 6 It can be Figure 3 or Figure 5A top view. Please refer to... Figure 3 and Figure 6 or in combination Figure 5 and Figure 6 The concave surface of the first surface D1 of the collimating lens T can be a cylinder, that is, a concave cylindrical surface, and the generatrix of the cylinder is parallel to the fast axis of the laser beam incident on the concave surface (e.g., parallel to the axis of rotation). Figure 6 (In the y-direction). It should be noted that a cylindrical surface is a curved surface formed by moving a straight line parallel to a fixed curve; this moving straight line is called the generatrix of the cylindrical surface. If the cylindrical surface can be a portion of the side surface of a cylinder, the generatrix of the cylindrical surface is parallel to the height direction of the cylinder. The curvature of the concave cylindrical surface on the fast axis of the incident laser is 0, and the radius of curvature is infinitely large. The curvature of the concave cylindrical surface on the slow axis of the incident laser is greater than 0.

[0046] It should be noted that on the fast axis of the laser incident on the concave cylindrical surface, the surface is approximately planar. The change in the divergence angle of the laser incident on the fast axis is similar to that of the laser incident on flat glass; the divergence angle on the fast axis remains essentially unchanged. However, on the slow axis of the laser incident on the concave curved surface, the curvature of the surface is greater, resulting in a larger divergence angle. After passing through the first surface D1, the virtual image size of the laser on the slow axis decreases, and the divergence angle increases. Figure 3 or Figure 5 As shown, after being injected into the concave cylindrical surface, the divergence angle of the laser on the slow axis increases, as... Figure 6 As shown, after the laser enters the concave cylindrical surface, the divergence angle of the laser on the fast axis does not increase significantly. Thus, when the laser propagates through the collimating lens and is then directed towards the convex arc surface in the second surface D2, the difference between the divergence angle on the slow axis and the divergence angle on the fast axis is small.

[0047] Optionally, the radius of curvature of the concave surface in the collimating lens on the slow axis of the incident laser can range from 50 mm to 120 mm, such as 109 mm. Optionally, compared to the divergence angle after entering the collimating lens in the prior art, in this embodiment, the divergence angle of the laser on the slow axis after passing through the concave surface can be increased by 1.5 degrees to 2.5 degrees, thus reducing the angular difference between the laser on the fast and slow axes.

[0048] After the laser beam incident on the collimating lens undergoes adjustment of its divergence angles on the fast and slow axes via the concave arc surface in the first surface D1 of the collimating lens, or adjustment of the divergence angle on the slow axis, it exits through the convex arc surface in the second surface D2 of the collimating lens. This convex arc surface further collimates the incident laser beam, thereby ensuring a better collimation effect for the laser beam exiting the collimating lens.

[0049] In the first optional implementation of the second surface D2, the convex arc surface in the second surface D2 has the same curvature on both the slow and fast axes of the incident laser, such as a portion of a sphere. Since the concave arc surface of the collimating lens already makes the difference in divergence angles on the fast and slow axes of the laser small, the convex arc surface can collimate the laser as a whole, making the reduction in the divergence angle on the fast axis similar to the reduction in the divergence angle on the slow axis. This eliminates the need for different designs of the curvature in different directions of the convex arc surface, ensuring a simpler fabrication process for the collimating lens.

[0050] In a second optional implementation of the second surface D2, the convex surface of D2 is a freeform surface. The radius of curvature of this convex surface on the slow axis of the incident laser is greater than its radius of curvature on the fast axis, and the curvature of the convex surface on the slow axis of the incident laser is less than its curvature on the fast axis. It should be noted that the convex surface of the lens has a converging effect on the incident light rays, and the smaller the radius of curvature of the convex surface, the greater its curvature, and thus the stronger its converging effect on the light rays, and the greater the reduction in the divergence angle. In this way, the convex surface can further adjust the divergence angle of the incident laser on the fast and slow axes, making the reduction in the divergence angle on the slow axis weaker than that on the fast axis, further reducing the difference in the divergence angle of the laser emitted from the collimating lens on the fast and slow axes. Thus, the convex surface collimates the incident laser, ensuring a good collimation effect for the laser emitted from the collimating lens. Figures 3 to 6 After the laser beam exits the convex surface of the collimating lens, it is nearly parallel on both the fast and slow axes.

[0051] Optionally, in a second alternative implementation of the second surface D2, the radius of curvature of the convex surface in the collimating lens on the fast axis of the incident laser can range from 2.592 mm to 3.888 mm, which is 3.24*(1-0.2) mm to 3.24*(1+0.2) mm. Alternatively, the radius of curvature of the convex surface on the fast axis of the incident laser can also range from 3.24*(1-0.1) mm to 3.24*(1+0.1) mm. The radius of curvature of the convex surface on the slow axis of the incident laser ranges from 2.608 mm to 3.924 mm; or it can also range from 2.608 mm to 3.912 mm, which is 3.26*(1-0.2) mm to 3.26*(1+0.2) mm. Optionally, the radius of curvature of the convex surface on the fast axis of the incident laser can range from 3.26*(1-0.1) mm to 3.26*(1+0.1) mm. Optionally, in this embodiment, the radius of curvature of the convex surface on the slow axis of the incident laser is less than 1.2 times its radius of curvature on the fast axis. That is, the difference between the radius of curvature of the convex surface on the slow axis and the radius of curvature on the fast axis is less than 20% of the radius of curvature on the fast axis. Optionally, this difference can also be less than 10% of the radius of curvature on the fast axis.

[0052] Optionally, in this embodiment, the required focal length of the collimating lens can be set first, and then the specific parameters of the collimating lens can be determined based on this focal length. For example, the radii of curvature of the convex surface of the collimating lens on the slow and fast axes of the incident laser, and the radii of curvature of the concave surface. The focal length of the collimating lens on the fast axis of the incident laser can be greater than half of the radii of curvature of the convex surface on the fast axis, and less than 2.5 times the radii of curvature of the convex surface on the fast axis. For example, the above-mentioned example parameters, namely the radii of curvature of the convex surface of the collimating lens on the slow and fast axes of the incident laser, and the radii of curvature of the concave surface on the slow axis of the incident laser, can all be parameters set when the focal length of the collimating lens on the fast axis of the incident laser is 6 mm. When the required focal length of the collimating lens is other values, the specific parameters of the above-mentioned radii of curvature can be adjusted accordingly. For example, the radii of curvature can be adjusted proportionally according to the change in focal length. For example, when the focal length of the collimating lens on the fast axis of the incident laser is 6 mm, the radius of curvature of the convex surface in the collimating lens on the fast axis of the incident laser is 3.24 mm; if the focal length of the collimating lens on the fast axis of the incident laser is 12 mm, then the radius of curvature of the convex surface in the collimating lens on the fast axis of the incident laser is 6.48 mm.

[0053] In this embodiment, the two optional implementations of the first surface D1 of the collimating lens T can be arbitrarily combined with the two implementations of the second surface D2, resulting in four different shapes of collimating lenses. In the first type of collimating lens, both the first and second surfaces include freeform surfaces; in the second type, the first surface includes a concave cylindrical surface and the second surface includes a convex freeform surface; in the third type, the first surface includes a freeform surface and the second surface includes a spherical surface; and in the fourth type, the first surface includes a concave cylindrical surface and the second surface includes a spherical surface. In these four types of collimating lenses, the radii of curvature of the concave surface in the first surface and the convex surface in the second surface can satisfy a certain relationship to ensure better collimation of the incident laser light.

[0054] Optionally, the radius of curvature of the concave surface in the collimating lens can be greater than the radius of curvature of the convex surface, such as the ratio of the radius of curvature of the concave surface to that of the convex surface ranging from 1.5 to 4. For example, for the first and second type of collimating lenses, the radius of curvature of the concave surface on both the fast and slow axes of the incident laser can be greater than the radius of curvature of the convex surface on both the fast and slow axes. For the third and fourth type of collimating lenses, the concave surface in the collimating lens is a concave cylindrical surface, meaning the concave surface only bends on the slow axis of the incident laser; therefore, the radius of curvature of the concave surface can refer to the radius of curvature of the concave surface on the slow axis. The ratio of the radius of curvature of the concave surface on the slow axis of the incident laser to that of the convex surface on both the slow and fast axes can both range from 1.5 to 4. Optionally, the focal length of the collimating lens as a whole can be greater than 0, and the focal length f = 1 / R2 - 1 / R1, where R2 represents the radius of curvature of the convex surface in the collimating lens, and R1 represents the radius of curvature of the concave surface in the collimating lens.

[0055] In this embodiment, the radius of curvature of the concave surface of the collimating lens on the fast axis of the incident laser can be greater than that of the convex surface on the fast axis; similarly, the radius of curvature of the concave surface on the slow axis of the incident laser can be greater than that of the convex surface on the slow axis. This ensures that the collimating lens as a whole is used for collimating and converging light, meaning that the divergence angle of the laser exiting the collimating lens is smaller than the divergence angle of the laser entering the collimating lens. It should be noted that the concave surface can only reduce the difference in divergence angles of the incident laser on the slow and fast axes to a certain extent, but it is difficult to make the divergence angles of the laser on the slow and fast axes the same. Therefore, further adjustments are needed using the convex surface to ensure the consistency of the collimation effect of the laser exiting the collimating lens in different directions.

[0056] In the first optional implementation of the collimating lens, after each light-emitting component emits a laser beam to its corresponding collimating lens, the laser beam enters the collimating lens through its first surface. This first surface diffuses the laser beam at its divergence angle along the slow axis. Since the laser beam emitted by the light-emitting component has a larger divergence angle along the fast axis than along the slow axis, the difference between these two divergence angles can be reduced after passing through the first surface. The laser beam can exit the collimating lens through its second surface, which further reduces the divergence angle along the fast axis. This further reduces the difference in divergence angles between the fast and slow axes after the laser beam passes through the collimating lens, improving the overall collimation effect of the laser beam emitted from the laser.

[0057] In the second alternative implementation of the collimating lens Figure 7 This is a schematic diagram of a collimating lens according to another embodiment of this application. Figure 8 This is a schematic diagram of another collimating lens provided in another embodiment of this application. Figure 8 It can be Figure 7 A top view. (e.g.) Figure 7 and 8 As shown, the first surface D1 of the collimating lens is a plane, and the second surface D2 of the collimating lens has a convex arc surface; this convex arc surface is a freeform surface, and the radius of curvature of this convex arc surface on the slow axis of the incident laser is greater than the radius of curvature on the fast axis, as shown. Figure 7 The radius of curvature of the convex surface is greater than Figure 8 The radius of curvature of the convex surface. Optionally, the convex surface satisfies the following: the radius of curvature on the slow axis of the incident laser is in the range of 3.5 mm to 4 mm, and / or the radius of curvature on the fast axis of the incident laser is in the range of 3.1 mm to 3.3 mm. For example, the radius of curvature of the convex surface on the fast axis of the incident laser can be 3.282 mm.

[0058] It should be noted that the smaller the radius of curvature of the convex surface, the greater the curvature of the convex surface, and the better the focusing effect of the convex surface on the laser. In this embodiment, since the first surface of the collimating lens is a plane, the degree of change in the divergence angle of the incident laser on the slow axis is the same as the degree of change in the divergence angle on the fast axis. After the laser enters the first surface of the collimating lens, the difference between the divergence angle of the laser on the fast axis and the divergence angle on the slow axis is still large. Therefore, the difference between the divergence angle of the laser incident on the convex surface of the collimating lens on the fast axis and the divergence angle on the slow axis is still large. Since the radius of curvature of the convex surface of the collimating lens on the slow axis of the incident laser is greater than the radius of curvature on the fast axis, the focusing effect of the convex surface on the incident laser on the fast axis is stronger than the focusing effect on the slow axis, thereby reducing the difference in the divergence angle of the laser emitted from the collimating lens (that is, the laser emitted from the convex surface) on the fast axis and the slow axis.

[0059] Optionally, in this embodiment, the width of the collimating lens along the fast axis (e.g., the y-direction) of the incident laser is greater than its width along the slow axis (x-direction), and the top view of each collimating lens can be rectangular. The laser emitted by the light-emitting component forms an elliptical spot when it strikes the collimating lens. The major axis of this elliptical spot can be parallel to the long side of the rectangular collimating lens, and the minor axis of this elliptical spot can be parallel to the short side of the rectangular collimating lens. This ensures a high degree of matching between the shape of the laser spot striking the collimating lens and the shape of the collimating lens. While ensuring that all laser light is directed towards the collimating lens, it avoids wasting the size of the collimating lens, which is beneficial for the miniaturization of the laser.

[0060] The following explanation, with reference to the accompanying diagram, details two possible implementation methods for the alignment lens group:

[0061] In one possible implementation of the collimating lens group Figure 9 This is a schematic diagram of a collimating lens assembly provided in an embodiment of this application. Figure 10 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application. Figure 11 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application. Figure 10 and Figure 11 All can be Figure 9 The collimating lens assembly shown is a right view. The collimating lens assembly 105 can be integrally formed. The collimating lens assembly 105 can have an incident surface M1 and an exit surface M2, which are two opposing surfaces in the collimating lens assembly 105. The incident surface M1 is closer to the housing 101 than the exit surface M2. The incident surface M1 of the collimating lens assembly 105 includes the first surface D1 of each collimating lens in the collimating lens assembly 105, and the exit surface M2 includes the second surface D2 of each collimating lens. In the first optional implementation of the collimating lens described above, such as... Figure 10 As shown, the incident surface M1 of the collimating lens group 105 has multiple concave arc surfaces, and the exit surface M2 of the collimating lens group 105 has multiple convex arc surfaces. Each concave arc surface and its corresponding convex arc surface constitute a collimating lens T. Optionally, the orthographic projection of each convex arc surface onto the incident surface of the collimating lens group 105 can coincide with the orthographic projection of the corresponding convex arc surface onto that incident surface. In the second optional implementation of the collimating lens described above, as... Figure 11 As shown, the incident surface of the collimating lens group 105 is a plane, and the exit surface M2 of the collimating lens group 105 has multiple convex arc surfaces. Each part of the collimating lens group 105 containing a convex arc surface is a collimating lens T.

[0062] In another alternative implementation of the collimating lens group Figure 12 This is a schematic diagram of another collimating lens assembly provided in an embodiment of this application. For example... Figure 12As shown, the collimating lens group 105 can also be composed of multiple independent collimating lenses T. For example, the laser may also include a support frame K, the edge of which can be fixed to the outer edge of the sealing cover away from the surface of the tube shell. The support frame may have multiple hollow areas (not shown in the figure), and each collimating lens T in the collimating lens group 105 can cover one of these hollow areas. These hollow areas can correspond one-to-one with multiple light-emitting components in the laser, and the laser emitted by each light-emitting component can pass through the corresponding hollow area and be directed towards the collimating lens T covering that hollow area.

[0063] In this embodiment, the laser 10 can be a multi-chip laser diode (MCL) type laser, in which multiple light-emitting components can be arranged in multiple rows and columns in the tube housing. Figure 13 This is a schematic diagram of another laser structure provided in an embodiment of this application. Figure 13 It can be Figure 2 The top view, and Figure 13 The light-transmitting sealing assembly and collimating lens group in the laser are not shown in the diagram. Figure 2 It can be Figure 13 A schematic diagram of the midsection a-a'. (See diagram below.) Figure 13 As shown, the multiple light-emitting components 102 in the laser 10 can be arranged in an array. Figure 13 Taking a laser 10 as an example, which includes 20 light-emitting components 102 arranged in four rows and five columns. Optionally, the number of light-emitting components 102 in the laser 10 can be other numbers, and the multiple light-emitting components 102 in the laser 10 can also be arranged in other ways, such as the laser 10 may include 28 light-emitting components 102 arranged in four rows and seven columns, or 25 light-emitting components 102 arranged in five rows and five columns.

[0064] The laser in this embodiment can be a monochromatic MCL laser or a multicolor MCL laser. In a monochromatic MCL laser, all light-emitting components emit light of the same color, and the parameters of each collimating lens in the collimating lens group can be identical. A multicolor MCL laser can include various types of light-emitting components, and different types of light-emitting components can emit different colors of light. Optionally, for a multicolor MCL laser, the collimating lens group can include various collimating lenses with different parameters. The divergence angles of the lasers emitted by different types of light-emitting components may differ; the corresponding collimating lenses in the collimating lens group can be designed based on the divergence angles of the lasers emitted by each light-emitting component. Optionally, for a multicolor MCL laser, the parameters of each collimating lens in the collimating lens group can also be identical.

[0065] In this embodiment, a multicolor MCL laser is used as an example. The multiple light-emitting components 102 in the laser may include a first light-emitting component for emitting a first-color laser and a second light-emitting component for emitting a second-color laser. The divergence angle of the first-color laser is smaller than the divergence angle of the second-color laser. The collimating lens group 105 can satisfy the following: the reduction in the divergence angle of the incident laser by the collimating lens corresponding to the first light-emitting component is less than the reduction in the divergence angle of the incident laser by the collimating lens corresponding to the second light-emitting component. The radius of curvature of the concave surface in the collimating lens corresponding to the first light-emitting component can be smaller than the radius of curvature of the concave surface in the collimating lens corresponding to the second light-emitting component; and / or, the radius of curvature of the convex surface in the collimating lens corresponding to the first light-emitting component can be larger than the radius of curvature of the concave surface in the collimating lens corresponding to the second light-emitting component.

[0066] For example, the first color may include blue and green, and the first light-emitting component may include a blue light-emitting component and a green light-emitting component; the second color may be red, and the second light-emitting component may be a red light-emitting component. The divergence angle of the red laser emitted by the red light-emitting component may be greater than the divergence angle of the blue laser emitted by the blue light-emitting component, and also greater than the divergence angle of the green laser emitted by the green light-emitting component. Optionally, the divergence angle of the red laser on both the fast and slow axes may be greater than the divergence angles of the green and blue lasers on the fast and slow axes, respectively. Alternatively, the divergence angle of the red laser on the fast axis may be greater than the divergence angles of the green and blue lasers on the fast axis, and the divergence angle of the red laser on the slow axis may also be greater than the divergence angles of the green and blue lasers on the slow axis, but the divergence angle of the red laser on the slow axis may be less than the divergence angles of the blue and green lasers on the fast axis. Based on the divergence angles of red, blue, and green lasers on the fast and slow axes, the amount by which the collimating lens corresponding to the light-emitting component emitting each color of laser reduces the laser divergence angle can be adjusted accordingly, such as by adjusting the radius of curvature of the convex surface of the collimating lens on the fast and slow axes.

[0067] For example, the divergence angle of the blue laser on the fast axis is greater than that of the red laser on the slow axis, but less than the divergence angle of the red laser on the fast axis of the incident laser. In this case, if the collimating lens in the collimating lens group adopts the first feasible method described above, the radius of curvature of the concave surface of the collimating lens towards which the blue laser is directed on the slow axis can be greater than the radius of curvature of the concave surface of the collimating lens towards which the red laser is directed on the slow axis, but less than the radius of curvature of the concave surface of the collimating lens towards which the red laser is directed on the fast axis. Alternatively, the radius of curvature of the convex surface of the collimating lens towards which the blue laser is directed on the slow axis is less than the radius of curvature of the convex surface of the collimating lens towards which the red laser is directed on the slow axis, but greater than the radius of curvature of the concave surface of the collimating lens towards which the red laser is directed on the fast axis. If the collimating lens in the collimating lens group adopts the second feasible method described above, then the radius of curvature of the convex surface on the fast axis in the collimating lens towards which the blue laser is directed can be greater than the radius of curvature of the convex surface on the fast axis in which the red laser is directed, but smaller than the radius of curvature of the convex surface on the slow axis in which the red laser is directed. Other relationships regarding the divergence angles of lasers of various colors can be deduced similarly, and will not be elaborated further in the embodiments of this application.

[0068] In this embodiment, the red light-emitting component of the laser can contain multiple light-emitting points, and the size of the red laser spot emitted by each red light-emitting component on the fast axis can reach 350 micrometers. The blue and green light-emitting components can each contain only one light-emitting point, and the size of the laser spot emitted by the blue and green light-emitting components on the fast axis can be around 35 micrometers, while the size of the laser emitted by each component on the slow axis is around 1 micrometer. Thus, the laser spot emitted by each light-emitting component in the laser is elongated and flat. After the laser is collimated by the collimating lens, the aspect ratio of the resulting spot can be reduced.

[0069] Figure 14 This is a schematic diagram of another laser structure provided in the embodiments of this application. Figure 14 It can be Figure 13 A schematic diagram of the midsection b-b'. Please refer to... Figure 2 , Figure 13 and Figure 14The housing 101 may include a base plate 1011 and an annular sidewall 1012 fixed to the base plate 1011. The base plate 1011 and the sidewall 1012 enclose a receiving space for the housing 101. The opening in the sidewall 1012 away from the base plate 1011 is the opening of the housing 101. Each light-emitting component 102 may include a light-emitting chip 1021, a heat sink 1022, and a reflective prism 1023. The heat sink 1022 may be disposed on the base plate 1011 of the housing 101, and the light-emitting chip 1021 may be disposed on the heat sink 1022. The heat sink 1022 is used to assist in heat dissipation of the light-emitting chip 1021, and the reflective prism 1023 may be located on the light-emitting side of the light-emitting chip 1021. The laser emitted by the light-emitting chip 1021 can be directed toward the reflecting prism 1023, and then reflected on the reflecting prism 1023 to pass through the light-transmitting sealing layer 104 and be directed toward the collimating lens group 105, and toward the collimating lens T corresponding to the light-emitting component 102 where the light-emitting chip 1021 is located in the collimating lens group 105.

[0070] Optionally, the laser contains an array of multiple light-emitting chips, and the collimating lens group contains an array of multiple collimating lenses. The row direction of the light-emitting chips is the same as the row direction of the collimating lenses, and the column direction of the light-emitting chips is the same as the column direction of the collimating lenses. The light emission direction of each light-emitting chip can be perpendicular to the row direction of the multiple light-emitting chips, that is, parallel to the column direction of the multiple light-emitting chips. The slow axis of the laser emitted by the light-emitting chips can be parallel to the row direction. When the laser is directed towards the collimating lens group, the slow axis is parallel to the row direction of the collimating lenses, and the fast axis is parallel to the column direction of the collimating lenses.

[0071] Please refer to Figure 13 and Figure 14 The light-emitting chip 1021 can be rectangular, and the laser beam is emitted from the end face G opposite to the corresponding reflecting prism 1023 of the light-emitting chip 1021. The actual light-emitting area in this end face G can be rectangular, for example, the length of which can be greater than 10 micrometers, such as 200 micrometers, and the width can be approximately 1 micrometer. The length direction of the rectangular light-emitting area can be parallel to the surface of the base plate 1011, and the width direction can be perpendicular to the surface of the base plate 1011. The fast axis of the laser emitted by the light-emitting chip 1021 can be parallel to the width direction, and the slow axis of the laser can be parallel to the length direction. For example, the divergence angle of the laser on the fast axis can be 30 degrees, and the divergence angle on the slow axis can be 7 degrees.

[0072] For example, the collimation effect of a collimating lens on a laser in a certain direction is related to the width of the laser's emission region in that direction. For instance, Y = f * tanQ, where Y represents the width of the emission region, f represents the focal length of the collimating lens, and Q represents the divergence angle of the laser emitted from that region after passing through the collimating lens. In the embodiments of this application, for the collimation effect of the collimating lens on the laser on the slow axis, Y = 200 micrometers = 0.2 millimeters, f = 6 millimeters, and thus Q ≈ 1. However, for the collimation effect of the collimating lens on the laser on the fast axis, since the Y value is too small, the obtained Q is close to 0. Therefore, if only collimating lenses with the same curvature on both the slow and fast axes are used to collimate the laser emitted from the light-emitting chip, even when the divergence angle on the fast axis is reduced to ensure collimation on the fast axis, the divergence angle on the slow axis is still approximately 1 degree, which is detrimental to laser shaping and subsequent propagation. In this embodiment, a collimating lens with a first surface set as a concave cylindrical surface, a freeform surface, or a plane, and a second surface set as a freeform surface, can be used to adjust the divergence angle of the laser in the slow axis direction and the divergence angle in the fast axis direction respectively, thereby improving the shaping and collimation effect of the collimating lens on the laser.

[0073] The following describes the housing and light-transmitting sealing assembly in the laser of this application embodiment:

[0074] Optionally, the bottom plate and sidewalls in the casing can be an integral structure or independent structures, formed by welding together to form the casing. In this embodiment, the casing material can be copper, such as oxygen-free copper, the light-transmitting sealing layer material can be glass, and the sealing cover material can be stainless steel. It should be noted that copper has a high thermal conductivity. In this embodiment, the casing material is copper, which ensures that the heat generated by the light-emitting component mounted on the bottom plate during operation can be quickly conducted through the casing and dissipated quickly, avoiding heat accumulation that could damage the light-emitting component. Optionally, the casing material can also be one or more of aluminum, aluminum nitride, and silicon carbide. In this embodiment, the sealing cover material can also be other Kovar materials, such as iron-nickel-cobalt alloys or other alloys. The light-transmitting sealing layer material can also be other light-transmitting and reliable materials, such as resin materials.

[0075] Please continue to refer to this. Figure 2 , Figure 13 and Figure 14The thickness of the outer edge of the sealing cover 103 in the light-transmitting sealing assembly can be less than a preset thickness threshold. This thinner outer edge can be fixed to the side of the opening of the tube shell 101 using parallel sealing welding technology. Alternatively, the outer edge of the sealing cover 103 can be fixed to the surface of the sidewall 1012 away from the bottom plate 1011 using parallel sealing welding technology. Optionally, the sealing cover 103 can be a sheet metal part, with the same or approximately the same thickness at various locations. The inner edge of the sealing cover 103 can be recessed relative to the outer edge towards the bottom plate 1011. The sealing cover 103 can be manufactured using sheet metal processes, such as stamping an annular plate structure, causing appropriate bending, recessing, or protrusion at suitable locations within the plate structure to obtain the sealing cover provided in this embodiment.

[0076] The light-transmitting sealing layer 104 can be a plate-like structure. This plate-like structure may include two parallel, larger surfaces and multiple smaller side surfaces connecting the two surfaces. The side surfaces of the light-transmitting sealing layer 104 can be fixed to the inner edge of the sealing cover plate 103 using sealant. In this embodiment, the light-transmitting sealing layer can be directly fixed to the sealing cover plate, or the laser may further include a support frame for supporting the light-transmitting sealing layer. The light-transmitting sealing layer can be first fixed to the support frame, and then the support frame can be fixed to the sealing cover plate. For example, the support frame can be a rectangular frame, so that the middle area of ​​the light-transmitting sealing layer can be supported by the support frame, thereby improving the stability of the light-transmitting sealing layer. Optionally, at least one of the surfaces of the light-transmitting sealing layer near the base plate and away from the base plate may also be covered with a brightness enhancement film to improve the output brightness of the laser.

[0077] The housing 101, the sealing cover 103, and the light-transmitting sealing layer 104 can form a sealed space, allowing the light-emitting component 102 to be placed within the sealed space and preventing water and oxygen from corroding the light-emitting component 102. Furthermore, by reducing the risk of the light-transmitting sealing layer 104 cracking due to the heat generated during the operation of the light-emitting component 102, the sealing effect of the sealed space can be guaranteed, thereby extending the lifespan of the light-emitting component.

[0078] In this embodiment, when fixing the outer edge of the sealing cover 103 to the tube shell 101 using parallel sealing welding technology, the sealing cover 103 is first placed on the side where the opening of the tube shell 101 is located, with the outer edge of the sealing cover 103 overlapping the surface of the side wall 1012 of the tube shell 101 away from the bottom plate 1011. Then, the outer edge is heated using a sealing welding device to melt the connection between the outer edge and the side wall 1012, thereby welding the outer edge to the side wall of the tube shell 101. Optionally, before fixing the sealing cover 103 to the tube shell 101, the light-transmitting sealing layer 104 can be fixed to the sealing cover 103, for example, by using an adhesive to fix the edge of the light-transmitting sealing layer 104 to the inner edge of the sealing cover 103. This adhesive can cover the side surface of the light-transmitting sealing layer 104 to ensure reliable adhesion of the light-transmitting sealing layer. After fixing the sealing cover 103 to the housing 101, the collimating lens assembly 105 can be suspended in the air to adjust the collimation effect. After adjusting and determining the position of the collimating lens assembly 105, an adhesive is applied to the outer edge of the sealing cover 103, and then the collimating lens assembly 105 is fixed to the sealing cover 103 by the adhesive.

[0079] Please refer to Figure 2 and Figure 13 The sidewalls 1012 of the housing 101 may have multiple openings on opposite sides. The laser 10 may also include multiple conductive pins 106, which can extend through the openings in the sidewalls 101 into the housing 101 and be fixed to it. The conductive pins 106 can be electrically connected to the electrodes of the light-emitting chip in the light-emitting component 102 to transmit external power to the light-emitting chip, thereby exciting the light-emitting chip to emit light. Optionally, the aperture of the opening can be 1.2 mm, and the diameter of the conductive pins 106 can be 0.55 mm.

[0080] Optionally, in the embodiments of this application, when assembling the laser, an annular solder structure (such as an annular glass bead) can be placed in the opening on the side wall of the tube shell first, and the conductive pins can be passed through the solder structure and the opening where the solder structure is located. Then, the side wall is placed around the perimeter of the base plate, and an annular silver-copper solder is placed between the base plate and the tube shell. Then, the structure of the base plate, side wall and conductive pins is placed in a high-temperature furnace for sealing sintering. After sealing sintering and curing, the base plate, side wall, conductive pins and solder can be integrated into a whole, thereby achieving airtightness at the side wall opening. Alternatively, the light-transmitting sealing layer can be fixed to the sealing cover plate, such as by pasting the edge of the light-transmitting sealing layer to the inner edge of the sealing cover plate to obtain the upper cover assembly. Then, the light-emitting component can be welded to the base plate in the accommodating space of the tube shell, and then the upper cover assembly can be welded to the surface of the side wall of the tube shell away from the base plate using parallel sealing welding technology. Finally, the collimating lens group is fixed to the side of the upper cover assembly away from the base plate with epoxy glue, thus completing the assembly of the laser. It should be noted that the above assembly process is only an exemplary process provided by the embodiments of this application. The welding process used in each step can be replaced by other processes, and the order of each step can also be adjusted. The embodiments of this application do not limit this.

[0081] In summary, in the laser provided in this application embodiment, after each light-emitting component emits laser light to the corresponding collimating lens, the collimating lens can reduce the divergence angle of the laser light to collimate it. Since the divergence angle of the laser light on the fast axis is greater than that on the slow axis, the collimating lens in this application embodiment can ensure that the reduction in the divergence angle on the slow axis after passing through the collimating lens is less than the reduction in the divergence angle on the fast axis. Therefore, in this application, the difference in divergence angle between the fast and slow axes can be reduced after the laser light passes through the collimating lens, improving the overall collimation effect of the laser light emitted by the laser.

[0082] It should be noted that in the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "at least one" refers to one or more. The term "multiple" refers to two or more, unless otherwise expressly defined. In this application, the term "at least one of A and B" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, "at least one of A and B" can represent: A existing alone, A and B existing simultaneously, and B existing alone. In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent: A existing alone, A and B existing simultaneously, and B existing alone. "Approximately," "about," "basically," and "close to" mean that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and substantially achieve the technical effect. In the accompanying drawings, the dimensions of layers and regions may be exaggerated for clarity of illustration. Moreover, it is understood that when an element or layer is referred to as being "on" another element or layer, it can be directly on other elements, or there may be intermediate layers. Similar reference marks throughout indicate similar elements.

[0083] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A laser, characterized in that, The laser includes: A tubular shell, one side of which has an opening; Multiple light-emitting components are located in the accommodating space of the tube shell; A light-transmitting sealing assembly is located on the side of the opening of the tube shell; The collimating lens assembly is located on the side of the light-transmitting sealing assembly away from the tube shell; The collimating lens group includes multiple collimating lenses that correspond one-to-one with the multiple light-emitting components. Each light-emitting component is used to emit laser light to the corresponding collimating lens. The collimating lens is used to reduce the divergence angle of the incident laser light, and to make the reduction in the divergence angle of the laser light on the slow axis less than the reduction in the divergence angle on the fast axis. The laser emitted by the light-emitting component enters the collimating lens through the first surface of the collimating lens and exits the collimating lens through the second surface of the collimating lens. The first surface is used to increase the divergence angle of the incident laser on the slow axis; the second surface is used to decrease the divergence angle of the incident laser on both the fast and slow axes. The second surface includes a convex arc surface, which is a freeform surface, and the radius of curvature of the convex arc surface on the slow axis is greater than the radius of curvature on the fast axis; The plurality of light-emitting components include a first light-emitting component for emitting a laser of a first color and a second light-emitting component for emitting a laser of a second color, wherein the divergence angle of the first color laser is smaller than the divergence angle of the second color laser. The reduction in the divergence angle of the incident laser by the collimating lens corresponding to the first light-emitting component is less than the reduction in the divergence angle of the incident laser by the collimating lens corresponding to the second light-emitting component. The radius of curvature of the convex surface in the collimating lens corresponding to the first light-emitting component is greater than the radius of curvature of the convex surface in the collimating lens corresponding to the second light-emitting component; The radius of curvature of the convex arc surface on the fast axis ranges from 2.592 mm to 3.888 mm, and the radius of curvature on the slow axis ranges from 2.608 mm to 3.924 mm. The radius of curvature of the convex arc surface on the slow axis is less than 1.2 times the radius of curvature on the fast axis; The focal length of the collimating lens on the fast axis is greater than half the radius of curvature of the convex surface on the fast axis, and less than 2.5 times the radius of curvature of the convex surface on the fast axis. The first surface includes a concave arc surface, the radius of curvature of which is greater than the radius of curvature of the convex arc surface; The ratio of the radius of curvature of the concave arc surface to the radius of curvature of the convex arc surface ranges from 1.5 to 4. The focal length of the collimating lens as a whole is greater than 0, and the focal length f = 1 / R2 - 1 / R1, where R2 represents the radius of curvature of the convex surface in the collimating lens, and R1 represents the radius of curvature of the concave surface in the collimating lens.

2. The laser according to claim 1, characterized in that, The first surface includes a concave arc surface, wherein the radius of curvature of the concave arc surface on the slow axis is smaller than the radius of curvature on the fast axis.

3. The laser according to claim 2, characterized in that, The first surface includes a concave cylindrical surface, and the generatrix of the concave cylindrical surface is parallel to the fast axis.

4. The laser according to claim 1, characterized in that, The first surface of the collimating lens is a plane.

5. The laser according to claim 4, characterized in that, The convex arc surface satisfies the following conditions: the radius of curvature on the slow axis is in the range of 3.5 mm to 4 mm, and / or the radius of curvature on the fast axis is in the range of 3.1 mm to 3.3 mm.

6. The laser according to claim 1, characterized in that, The collimating lens assembly is integrally formed.

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