Spatial beam combining method for semiconductor laser modules

Abstract

Disclosed in the embodiments of the present application is a spatial beam combining method for semiconductor laser modules. The method comprises: acquiring a first radius of curvature of a second lens and a second radius of curvature of a third lens to determine a first adjustment instruction and a second adjustment instruction; on the basis of the first adjustment instruction and the second adjustment instruction, adjusting the second lens and the third lens; controlling a first light beam emitted by a first semiconductor laser chip to be transmitted into a polarizing beam splitter via a first lens and the adjusted second lens; and controlling a second beam emitted by a second semiconductor laser chip to be transmitted into the polarizing beam splitter successively via the first lens, the adjusted third lens and a reflector, such that by means of the polarizing beam splitter, the first light beam and the second light beam are polarization-combined into a third optical path to form a third light beam, the third light beam being coupled into an optical fiber via a fourth lens.

Description

Spatial beam combining method for semiconductor laser modules

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202410385070.7 filed on April 1, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of optical technology, and in particular to a spatial beam combining method for a semiconductor laser module. Background Art

[0004] Semiconductor lasers are increasingly used in communications, military, medical and other fields. As a semiconductor component, the market demand for semiconductor lasers is constantly increasing. In recent years, high-power, high-beam-quality semiconductor lasers have developed rapidly.

[0005] In related technologies, the spatial beam combining method for semiconductor laser modules involves fusing the light output from multiple semiconductor lasers to a fiber-coupled semiconductor laser module, and then placing multiple semiconductor lasers in parallel within the housing of the semiconductor laser module. To increase output power, both the number of semiconductor lasers installed and the output power of a single semiconductor laser can be increased.

[0006] However, increasing the number of semiconductor lasers in a semiconductor laser module or increasing the output power of a single semiconductor laser are both limited by the overall space of the semiconductor laser module, thus affecting the maximum output power. Therefore, how to increase the output power of a semiconductor laser module without changing the size of the semiconductor laser module is a technical problem that needs to be solved urgently.

[0007] Summary of the Invention

[0008] The embodiments of the present application provide a spatial beam combining method for a semiconductor laser module to solve the technical problem of being unable to increase the output power of a semiconductor laser module when the overall space of the semiconductor laser module remains unchanged.

[0009] On the one hand, to solve the above technical problems, embodiments of the present application provide a spatial beam combining method for a semiconductor laser module, wherein the semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. A first semiconductor laser chip, a first lens, and a second lens are sequentially provided along the first optical path in the semiconductor laser module. A second semiconductor laser chip, the first lens, a third lens, and a reflector are sequentially provided along the second optical path in the semiconductor laser module. A polarization beam splitter and a fourth lens are sequentially provided along the third optical path in the semiconductor laser module. The spatial beam combining method for the semiconductor laser module comprises the following steps:

[0010] Obtaining a first curvature radius of a vertex of the aspheric curve on which the second lens is located, and a second curvature radius of a vertex of the aspheric curve on which the third lens is located;

[0011] determining a first adjustment instruction for the second lens in the first optical path according to the first curvature radius, and determining a second adjustment instruction for the third lens in the second optical path according to the second curvature radius;

[0012] adjusting the second lens and the third lens in the first optical path and the second optical path respectively according to the first adjustment instruction and the second adjustment instruction;

[0013] The first light beam emitted by the first semiconductor laser chip is controlled to be transmitted to the polarization beam splitter through the first lens and the adjusted second lens respectively. The second light beam emitted by the second semiconductor laser chip is controlled to be transmitted to the polarization beam splitter through the first lens, the adjusted third lens, and the reflector in sequence, so that the first light beam and the second light beam are polarized and combined into the third light path through the polarization beam splitter to form a third light beam, and the third light beam is coupled into the optical fiber through the fourth lens.

[0014] In the embodiment of the present application, the second lens and the third lens are collimating and reflecting lenses.

[0015] In the embodiment of the present application, the collimating and reflecting integrated lens is an off-axis parabolic lens.

[0016] In an embodiment of the present application, the step of determining a first adjustment instruction for the second lens in the first optical path according to the first curvature radius, and determining a second adjustment instruction for the third lens in the second optical path according to the second curvature radius includes:

[0017] determining a first off-axis amount of the second lens according to the first curvature radius, and determining a second off-axis amount of the third lens according to the second curvature radius;

[0018] A first adjustment instruction for the second lens in the first optical path is determined based on the first off-axis amount, and a second adjustment instruction for the third lens in the second optical path is determined based on the second off-axis amount.

[0019] In an embodiment of the present application, before the steps of determining a first off-axis amount of the second lens according to the first curvature radius and determining a second off-axis amount of the third lens according to the second curvature radius, the method further includes:

[0020] determining aspheric curves corresponding to the second lens and the third lens;

[0021] In the case where the aspheric curve is a parabolic curve, determining a curve equation of the parabolic curve;

[0022] The curve equation includes: 2 =2x / c;

[0023] Wherein, x and z are the horizontal and vertical coordinate values ​​of the parabola curve in a preset coordinate system, respectively, and c is the reciprocal of the curvature radius of the vertex of the parabola curve.

[0024] In an embodiment of the present application, the step of determining a first off-axis amount of the second lens according to the first curvature radius, and determining a second off-axis amount of the third lens according to the second curvature radius includes:

[0025] Determining a first ordinate of the second lens in the preset coordinate system based on the first curvature radius, the curve equation, and a first abscissa of the first focus of the second lens in the preset coordinate system, and determining the first ordinate as a first off-axis amount of the second lens;

[0026] The second vertical coordinate of the third lens in the preset coordinate system is determined according to the second curvature radius, the curve equation, and the second horizontal coordinate of the second focus of the third lens in the preset coordinate system, and the second vertical coordinate is determined as the second off-axis amount of the third lens.

[0027] In an embodiment of the present application, after the step of adjusting the second lens and the third lens in the first light path and the second light path respectively according to the first adjustment instruction and the second adjustment instruction, the method further includes:

[0028] Fine-tuning the second lens along the first optical path so that the second lens can couple the output power of the first semiconductor laser chip to a maximum;

[0029] The third lens is fine-tuned along the second optical path so that the third lens can couple the output power of the second semiconductor laser chip to a maximum.

[0030] In an embodiment of the present application, the second optical path further includes a half-wave plate, and the half-wave plate is located between the reflector and the polarization beam splitter.

[0031] In an embodiment of the present application, the third optical path further includes a mode stripper, and the mode stripper is used to couple the third light beam passing through the fourth lens into the optical fiber.

[0032] In an embodiment of the present application, the fourth lens is a collimating lens, and the collimating lens is used to converge the third light beam into the stripper.

[0033] An embodiment of the present application provides a spatial beam combining method for a semiconductor laser module. By obtaining a first curvature radius of a second lens and a second curvature radius of a third lens in the semiconductor laser module, a first adjustment instruction and a second adjustment instruction are determined. The second lens and the third lens can then be adjusted according to the first adjustment instruction and the second adjustment instruction. Furthermore, a first light beam emitted by a first semiconductor laser chip is controlled to pass through the first lens and the adjusted second lens to a polarization beam splitter. A second light beam emitted by a second semiconductor laser chip is controlled to pass through the first lens, the adjusted third lens, and a reflector in sequence to the polarization beam splitter. The first and second light beams are polarized and combined into a third optical path through the polarization beam splitter to form a third light beam. The third light beam is then coupled into an optical fiber through a fourth lens. In this way, the output power of the semiconductor laser module can be increased without changing the size of the semiconductor laser module. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0035] FIG1 is a schematic flow chart of a method for spatial beam combining of a semiconductor laser module provided in an embodiment of the present application;

[0036] FIG2 is a schematic structural diagram of a semiconductor laser module provided in an embodiment of the present application;

[0037] FIG3 is a schematic structural diagram of a semiconductor laser module provided in the related art;

[0038] FIG4 is a schematic diagram of the reflection principle of an off-axis parabolic lens provided in an embodiment of the present application;

[0039] FIG5 is a schematic diagram of calculating the off-axis value using the curve equation provided in an embodiment of the present application.

[0040] Among them, the numbers in the drawings of the specification are as follows: 10, first semiconductor laser chip; 11, second semiconductor laser chip; 12, first lens; 13, second lens; 14, third lens; 15, reflector; 16, half-wave plate; 17, polarization beam splitter; 18, fourth lens; 19, mold stripper; 20, optical fiber; 131, slow-axis collimating lens; 132, small reflector. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0042] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In the present application, " / " means "or".

[0043] Reference numerals and / or reference letters may be repeated in different examples in this application. This repetition is for the purpose of simplicity and clarity and does not in itself indicate a relationship between the various embodiments and / or configurations discussed.

[0044] In the embodiments of this application, semiconductor lasers are increasingly used in communications, military, medical and other fields. As a semiconductor component, semiconductor lasers are increasingly used in the market. In recent years, high-power, high-beam-quality semiconductor lasers have developed rapidly.

[0045] In related technologies, the spatial beam combining method for semiconductor laser modules involves fusing the light output from multiple semiconductor lasers to a fiber-coupled semiconductor laser module, and then placing multiple semiconductor lasers in parallel within the housing of the semiconductor laser module. To increase output power, both the number of semiconductor lasers installed and the output power of a single semiconductor laser can be increased.

[0046] However, methods of increasing the number of semiconductor lasers in a semiconductor laser module or increasing the output power of a single semiconductor laser are both limited by the overall space of the semiconductor laser module, thereby affecting the maximum output power.

[0047] Therefore, how to increase the output power of a semiconductor laser module without changing the size of the semiconductor laser module is a technical problem that needs to be solved urgently.

[0048] To solve the above technical problems, please refer to Figures 1 and 2. Figure 1 is a flow chart of a spatial beam combining method for a semiconductor laser module provided in an embodiment of the present application, and Figure 2 is a structural schematic diagram of a semiconductor laser module provided in an embodiment of the present application. Specifically, as shown in Figures 1 and 2, an embodiment of the present application provides a spatial beam combining method for a semiconductor laser module, wherein the semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. A first semiconductor laser chip 10, a first lens 12, and a second lens 13 are sequentially provided along the first optical path in the semiconductor laser module. A second semiconductor laser chip 11, the first lens 12, a third lens 14, and a reflector 15 are sequentially provided along the second optical path in the semiconductor laser module. A polarization beam splitter 17 and a fourth lens 18 are sequentially provided along the third optical path in the semiconductor laser module. In one embodiment, the first lens 12 provided in this embodiment can be a fast-axis collimating lens, and the fourth lens 18 can be a collimating lens.

[0049] Specifically, the spatial beam combining method of the semiconductor laser module provided in this embodiment includes steps 101 to 104;

[0050] Step 101 : Obtain a first curvature radius of a vertex of an aspheric curve on which the second lens is located, and a second curvature radius of a vertex of an aspheric curve on which the third lens is located.

[0051] In this embodiment, the positions of the second lens and the third lens in the semiconductor laser module provided in this embodiment are not determined. Therefore, it is necessary to determine the specific positions of the second lens and the third lens in the semiconductor laser module and deploy them so as to achieve the purpose of spatially combining the laser light emitted by the semiconductor laser chip in the semiconductor laser module.

[0052] Specifically, in differential geometry, the reciprocal of curvature is the radius of curvature. The curvature of a plane curve is the rotation rate of the tangent direction angle at a point on the curve with respect to the arc length. This is defined through differentiation to indicate the degree to which the curve deviates from a straight line. Thus, this embodiment can determine the first radius of curvature of the vertex of the aspheric curve where the second lens is located, and the second radius of curvature of the vertex of the aspheric curve where the third lens is located, through differential geometry calculations.

[0053] Step 102: Determine a first adjustment instruction for the second lens in the first optical path according to the first curvature radius, and determine a second adjustment instruction for the third lens in the second optical path according to the second curvature radius.

[0054] In the related art, please refer to Figure 3, which is a structural schematic diagram of a semiconductor laser module provided in the related art. As shown in Figure 3, the semiconductor laser module in the related art has a first optical path, a second optical path and a third optical path. Along the first optical path, a semiconductor laser chip, a fast-axis collimating lens, a slow-axis collimating lens 131, and a small reflector 132 are sequentially arranged; along the second optical path, a semiconductor laser chip, a fast-axis collimating lens, a slow-axis collimating lens 131, a small reflector 132, a large reflector, and a half-wave plate are sequentially arranged; along the third optical path, a polarization beam splitter and a fourth lens are sequentially arranged.

[0055] Referring to Figures 2 and 3 simultaneously, it can be seen that the semiconductor laser module provided in this embodiment is provided with a second lens and a third lens in the first and second optical paths, respectively, while the semiconductor laser modules in the related art are provided with a slow-axis collimating lens and a small reflector in the first and second optical paths, respectively. Thus, it can be seen that, while the overall spatial dimensions of the semiconductor laser module remain unchanged, the space occupied by the structural deployment solution within the semiconductor laser module provided in this embodiment is smaller than that occupied by the structural deployment solution within the semiconductor laser module in the related art. In other words, there is still room for expansion in the semiconductor laser module provided in this embodiment. Therefore, the semiconductor laser module provided in this embodiment can increase the output power of the semiconductor laser module with unchanged overall spatial dimensions by increasing the number of semiconductor laser chips provided or increasing the output power of a single semiconductor laser chip, thereby solving the technical problems existing in the related art.

[0056] In order to reduce the space occupied by the structural deployment scheme within the semiconductor laser module, the second lens and the third lens provided in this embodiment need to have the functions of the slow-axis collimating lens and the small reflector in the semiconductor laser module provided in the related art. Therefore, the second lens and the third lens provided in this embodiment can be a collimating and reflecting integrated lens, thereby achieving the purpose of replacing the slow-axis collimating lens and the small reflector.

[0057] In some embodiments, the collimating and reflecting integrated lens provided in this embodiment can be an off-axis parabolic lens. Specifically, please refer to Figure 4, which is a schematic diagram of the reflection principle of the off-axis parabolic lens provided in an embodiment of the present application. As shown in Figure 4, the off-axis parabolic lens provided in this embodiment can focus a parallel incident light beam to a focal point, or convert the light emitted by the light source into a parallel transmitted light beam, thereby realizing the collimation and reflection functions that can be achieved by the slow-axis collimating lens and the small reflector in the semiconductor laser module provided in the related art.

[0058] In this embodiment, the embodiment of the present application converts the transmissive collimation into reflective cylindrical collimation, and the reflector adopts an off-axis parabola. Compared with the transmissive collimation used in the related art, this embodiment can achieve smaller beam aberration and smaller size during folded beam shaping, thereby reducing the overall width of the semiconductor laser module and reducing the overall volume of the semiconductor laser module.

[0059] However, after determining to use an off-axis parabolic lens to replace the slow-axis collimating lens and the small reflector in the related art, it is also necessary to determine the deployment position of the off-axis parabolic lens (i.e., the second lens and the third lens) in the semiconductor laser module so that the incident light beam can be reflected to the polarization beam splitter, so as to perform polarization combination of the light beams incident from the first light path and the second light path through the polarization beam splitter.

[0060] Therefore, after determining the first radius of curvature of the vertex of the aspheric curve on which the second lens is located and the second radius of curvature of the vertex of the aspheric curve on which the third lens is located, this embodiment can determine the specific positions of the second lens and the third lens in the semiconductor laser module based on the curvature radii and the focal positions of the second lens and the third lens. Then, based on the current initial positions of the second lens and the third lens and the specific positions, a first adjustment instruction for adjusting the second lens in the first optical path and a second adjustment instruction for adjusting the third lens in the second optical path can be determined.

[0061] In one embodiment, the steps of determining a first adjustment instruction for the second lens in the first optical path based on the first radius of curvature and determining a second adjustment instruction for the third lens in the second optical path based on the second radius of curvature provided in this embodiment may specifically include: determining a first off-axis amount of the second lens based on the first radius of curvature, and determining a second off-axis amount of the third lens based on the second radius of curvature; determining a first adjustment instruction for the second lens in the first optical path based on the first off-axis amount, and determining a second adjustment instruction for the third lens in the second optical path based on the second off-axis amount.

[0062] In this embodiment, the second lens and the third lens provided in this embodiment are both off-axis parabolic lenses. Therefore, this embodiment can determine a first off-axis amount of the second lens and a second off-axis amount of the third lens based on the corresponding curvature radii of the second lens and the third lens. The first off-axis amount and the second off-axis amount are the distances between the second lens and the third lens and their corresponding focal points. Therefore, based on the first off-axis amount and the second off-axis amount, a first adjustment instruction and a second adjustment instruction for adjusting the second lens and the third lens can be determined.

[0063] In one embodiment, the aspheric curves corresponding to the second lens and the third lens can be confined to a preset coordinate system, so that the actual off-axis amounts of the second lens and the third lens can be solved through specific coordinate values ​​in the coordinate system.

[0064] Specifically, by substituting the off-axis parabolic lens at different positions in a preset coordinate system and using a light beam parallel to the horizontal axis as the incident light beam of the off-axis parabolic lens, the focal position of the off-axis parabolic lens can be determined in the coordinate system. Then, based on the focal positions of the off-axis parabolic lens at different positions in the coordinate system corresponding to the horizontal axis, the curve equation of the aspheric curve on which the off-axis parabolic lens is located can be derived. The curve equation can be:

[0065] Wherein, z is the ordinate of the point on the aspheric curve where the off-axis parabolic lens is located in the preset coordinate system, x is the abscissa of the point on the aspheric curve where the off-axis parabolic lens is located in the preset coordinate system, c is the curvature of the vertex of the aspheric curve where the off-axis parabolic lens is located, which is the inverse of the curvature radius of the vertex of the aspheric curve, k is the cone coefficient, and α is the aspheric coefficient.

[0066] Since the off-axis amount corresponding to the off-axis parabolic lens can be determined when the focus of the aspheric curve is located at the curvature radius position of 1 / 2 of the aspheric curve vertex on the horizontal axis, the off-axis amount corresponding to the off-axis parabolic lens can be obtained by substituting the curvature radius of 1 / 2 of the aspheric curve vertex as the horizontal coordinate value into the curve equation. Specifically, the off-axis amount is equal to the curvature radius of the aspheric curve vertex.

[0067] In this way, the method provided in the above embodiment can be used to determine the first off-axis amount and the second off-axis amount corresponding to the second lens and the third lens, respectively. Then, based on the first off-axis amount and the second off-axis amount, the first adjustment instruction and the second adjustment instruction for adjusting the second lens and the third lens can be determined, so as to adjust the positions of the second lens and the third lens in the semiconductor laser module. This can achieve the purpose of subsequent polarization beam combining of the two light paths after the semiconductor laser module is powered on.

[0068] In some embodiments, the curve equation provided in the above embodiment is applicable to calculating the off-axis amount of all off-axis parabolic lenses. However, when the aspheric curve corresponding to the off-axis parabolic lens is a parabolic curve, the conic coefficient k can be determined to be -1 and the aspheric coefficient α can be determined to be 0, thereby simplifying the above curve equation to obtain the simplified curve equation:

[0069] Specifically, please refer to Figure 5, which is a schematic diagram of solving the off-axis amount using the curve equation provided in an embodiment of the present application, wherein x and z are the horizontal and vertical coordinate values ​​of the parabolic curve in the preset coordinate system, respectively, c is the inverse of the radius of curvature of the vertex of the parabolic curve, d is the distance from the focus of the axial parabolic lens to the vertex of the parabolic curve, and s is the off-axis amount of the off-axis parabolic lens.

[0070] Therefore, before the steps of determining the first off-axis amount of the second lens according to the first curvature radius and determining the second off-axis amount of the third lens according to the second curvature radius provided in this embodiment, the spatial beam combining method of the semiconductor laser module provided in this embodiment may further include: determining an aspheric curve corresponding to the second lens and the third lens; when the aspheric curve is a parabolic curve, determining a curve equation of the parabolic curve; the curve equation includes: 2 =2x / c.

[0071] Then, based on the simplified curve equation, the off-axis amount of the off-axis parabolic lens can be quickly solved. Specifically, the steps of determining the first off-axis amount of the second lens based on the first radius of curvature and determining the second off-axis amount of the third lens based on the second radius of curvature provided in this embodiment can be specifically as follows: determining the first vertical coordinate of the second lens in the preset coordinate system based on the first radius of curvature, the curve equation, and the first horizontal coordinate of the first focus of the second lens in the preset coordinate system, and determining the first vertical coordinate as the first off-axis amount of the second lens; determining the second vertical coordinate of the third lens in the preset coordinate system based on the second radius of curvature, the curve equation, and the second horizontal coordinate of the second focus of the third lens in the preset coordinate system, and determining the second vertical coordinate as the second off-axis amount of the third lens.

[0072] After determining the first off-axis amount of the second lens and the second off-axis amount of the third lens, a first adjustment instruction and a second adjustment instruction for adjusting the second lens and the third lens can be determined.

[0073] In other embodiments, after determining the first off-axis amount of the second lens and the second off-axis amount of the third lens, a first spot range of the first light beam on the second lens can be determined based on the first off-axis amount, and the mirror size of the second lens can be adjusted based on the first spot range so that the mirror size of the second lens is larger than the first spot range. Similarly, a second spot range of the second light beam on the third lens can be determined based on the second off-axis amount, and the mirror size of the third lens can be adjusted based on the second spot range so that the mirror size of the third lens is larger than the second spot range.

[0074] Step 103 : Adjust the second lens and the third lens in the first optical path and the second optical path respectively according to the first adjustment instruction and the second adjustment instruction.

[0075] In this embodiment, the first adjustment instruction and the second adjustment instruction provided in this embodiment are mainly used to adjust the specific positions of the second lens and the third lens in the semiconductor laser module, so that the second lens and the third lens in the semiconductor laser module can transmit the first light beam and the second light beam to the polarization beam splitter, so that the first light beam and the second light beam can be polarized and combined by the polarization beam splitter, thereby achieving the purpose of enhancing the output power of the semiconductor laser module.

[0076] The single-path collimated light spot of the semiconductor laser module provided in this embodiment is almost the same as that of the semiconductor laser module provided in the related art. That is, the semiconductor laser module with relatively fewer devices provided in this embodiment can achieve the same effect as the semiconductor laser module with relatively more devices provided in the related art.

[0077] In one embodiment, to further increase the output power of the semiconductor laser module, this embodiment further requires fine-tuning the second lens and the third lens to maximize the output power coupling of the first semiconductor laser chip and the second semiconductor laser chip. Specifically, after adjusting the second lens and the third lens in the first optical path and the second optical path, respectively, according to the first adjustment instruction and the second adjustment instruction, the spatial beam combining method for the semiconductor laser module provided by this embodiment may further include: fine-tuning the second lens along the first optical path so that the second lens maximizes the output power coupling of the first semiconductor laser chip; and fine-tuning the third lens along the second optical path so that the third lens maximizes the output power coupling of the second semiconductor laser chip.

[0078] Step 104: Control the first light beam emitted by the first semiconductor laser chip to be transmitted to the polarization beam splitter through the first lens and the adjusted second lens, respectively; control the second light beam emitted by the second semiconductor laser chip to be transmitted to the polarization beam splitter through the first lens, the adjusted third lens, and the reflector, in sequence, so as to polarize and combine the first and second light beams into the third optical path through the polarization beam splitter to form a third light beam, and couple the third light beam into the optical fiber through the fourth lens.

[0079] After completing the adjustment and fine-tuning of the second lens and the third lens in the semiconductor laser module, the semiconductor laser module can be powered on, and the first light beam and the second light beam emitted by the first semiconductor laser chip and the second semiconductor laser chip can be controlled so that the first light beam and the second light beam are finally polarized and combined through the polarization beam splitter and finally coupled into the light, thereby achieving the purpose of increasing the output power of the semiconductor laser module.

[0080] In some embodiments, referring to FIG. 2 , a half-wave plate 16 may be further provided in the second optical path of the semiconductor laser module provided in this embodiment. The half-wave plate 16 is located between the reflector 15 and the polarization beam splitter 17. A mode stripper 19 may also be provided in the third optical path. The mode stripper 19 is used to couple the third light beam passing through the fourth lens 18 into the optical fiber 20. Specifically, the fourth lens 18 provided in this embodiment may be a collimating lens, which is used to converge the third light beam into the mode stripper 19.

[0081] In order to better illustrate the spatial beam combining method of the semiconductor laser module provided by the embodiment of the present application, please refer to Figure 2. This embodiment will be described with a specific embodiment: First, the first semiconductor laser chip is controlled to emit a first light beam which first passes through the first lens to collimate the first light beam in the fast axis direction, and then passes through the second lens to collimate the first light beam in the slow axis direction, and perform beam deflection. Among them, after the first light beam is collimated by the first lens and the second lens, parallel light is emitted, enters the focusing tube and converges on the beam quality analyzer. Among them, the center of mass coordinates and width reference standard parts, and the width needs to be adjusted back and forth along the first optical path direction by the second lens to the minimum position of the spot width. At this time, the position of the second lens is a coarse positioning position, and serves as a reference position for coupling the first lens to the rest of the way. After baking is completed, it is necessary to ensure that the center of mass coordinates and width changes are within a certain range.

[0082] Next, a stripper is mounted directly on the baseplate. Reverse light is transmitted through one end of the optical fiber. After being collimated by a collimator, the beam is converged by a focusing tube onto a beam quality analyzer, with the center of mass coordinates referenced to a standard. Following this, the second semiconductor laser chip and the third lens in the second optical path are adjusted in the same manner. A reflector is then used to direct the second beam in the second optical path and the first beam in the first optical path to a polarization beam splitter. The polarization beams are then combined by the polarization beam splitter to form a third beam in the third optical path. At this point, the initial positions of the second and third lenses are determined.

[0083] Next, fine-tune the second and third lenses to couple the power to maximum. Record the positions of the second and third lenses and fine-tune them again along their corresponding optical paths, simultaneously maximizing the power coupling until the power decreases as the second and third lenses are adjusted forward and backward. At this point, the second and third lenses are at their peak power positions, precisely where they need to be positioned.

[0084] Finally, according to the precise positions of the second lens and the third lens, as well as the positions of the remaining components, they are deployed in the semiconductor laser module. After the deployment is completed, the semiconductor laser module is powered on to achieve the purpose of spatial beam combining of the semiconductor laser module. This completes the detailed description of the spatial beam combining method of the semiconductor laser module.

[0085] In summary, an embodiment of the present application provides a spatial beam combining method for a semiconductor laser module, wherein the semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. A first semiconductor laser chip, a first lens, and a second lens are sequentially provided along the first optical path in the semiconductor laser module. A second semiconductor laser chip, a first lens, a third lens, and a reflector are sequentially provided along the second optical path in the semiconductor laser module. A polarization beam splitter and a fourth lens are sequentially provided along the third optical path in the semiconductor laser module. The spatial beam combining method for the semiconductor laser module includes the following steps: obtaining a first curvature radius of a vertex of an aspheric curve where the second lens is located, and a second curvature radius of a vertex of the aspheric curve where the third lens is located, and obtaining a first curvature radius of a vertex of the aspheric curve where the third lens is located according to the first and second optical paths. A first adjustment instruction for the second lens in the first optical path is determined based on a first curvature radius, a second adjustment instruction for the third lens in the second optical path is determined based on a second curvature radius, and the second lens and the third lens are adjusted in the first optical path and the second optical path respectively based on the first adjustment instruction and the second adjustment instruction, and the first light beam emitted by the first semiconductor laser chip is controlled to be transmitted to the polarization beam splitter through the first lens and the adjusted second lens respectively, and the second light beam emitted by the second semiconductor laser chip is controlled to be transmitted to the polarization beam splitter through the first lens, the adjusted third lens, and the reflector in sequence, so as to polarize and combine the first and second light beams into the third optical path through the polarization beam splitter to form a third light beam, and couple the third light beam into the optical fiber through the fourth lens. By using the embodiments of the present application, the output power of the semiconductor laser module can be increased without changing the size of the semiconductor laser module.

[0086] Some embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referenced to each other.

[0087] The above are merely specific embodiments of the present application to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but rather is intended to conform to the widest scope consistent with the principles and novel features of the present application.

Claims

1. A method for spatial beam combining of semiconductor laser modules, wherein: The semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. A first semiconductor laser chip, a first lens, and a second lens are sequentially provided along the first optical path in the semiconductor laser module. A second semiconductor laser chip, the first lens, a third lens, and a reflector are sequentially provided along the second optical path in the semiconductor laser module. A polarization beam splitter and a fourth lens are sequentially provided along the third optical path in the semiconductor laser module. The spatial beam combining method of the semiconductor laser module includes the following steps: Obtaining a first curvature radius of a vertex of the aspheric curve on which the second lens is located, and a second curvature radius of a vertex of the aspheric curve on which the third lens is located; determining a first adjustment instruction for the second lens in the first optical path according to the first curvature radius, and determining a second adjustment instruction for the third lens in the second optical path according to the second curvature radius; adjusting the second lens and the third lens in the first optical path and the second optical path respectively according to the first adjustment instruction and the second adjustment instruction; The first light beam emitted by the first semiconductor laser chip is controlled to be transmitted to the polarization beam splitter through the first lens and the adjusted second lens respectively. The second light beam emitted by the second semiconductor laser chip is controlled to be transmitted to the polarization beam splitter through the first lens, the adjusted third lens, and the reflector in sequence, so that the first light beam and the second light beam are polarized and combined into the third light path through the polarization beam splitter to form a third light beam, and the third light beam is coupled into the optical fiber through the fourth lens.

2. The spatial beam combining method of a semiconductor laser module according to claim 1, wherein: The second lens and the third lens are collimating and reflecting lenses in one.

3. The spatial beam combining method of a semiconductor laser module according to claim 2, wherein: The collimating and reflecting integrated lens is an off-axis parabolic lens.

4. The spatial beam combining method of a semiconductor laser module according to claim 3, wherein: The steps of determining a first adjustment instruction for the second lens in the first optical path according to the first radius of curvature, and determining a second adjustment instruction for the third lens in the second optical path according to the second radius of curvature include: determining a first off-axis amount of the second lens according to the first radius of curvature, and determining a second off-axis amount of the third lens according to the second radius of curvature; determining a first adjustment instruction for the second lens in the first optical path based on the first off-axis amount, and determining a second adjustment instruction for the third lens in the second optical path based on the second off-axis amount.

5. The spatial beam combining method of a semiconductor laser module according to claim 4, wherein: Before the steps of determining the first off-axis amount of the second lens according to the first curvature radius and determining the second off-axis amount of the third lens according to the second curvature radius, the method further includes: determining aspheric curves corresponding to the second lens and the third lens; when the aspheric curves are parabolic curves, determining a curve equation of the parabolic curve; the curve equation includes: z 2 =2x / c; wherein, x and z are the horizontal and vertical coordinate values ​​of the parabola curve in a preset coordinate system, respectively, and c is the reciprocal of the curvature radius of the vertex of the parabola curve.

6. The spatial beam combining method of a semiconductor laser module according to claim 5, wherein: The steps of determining a first off-axis amount of the second lens based on the first radius of curvature and determining a second off-axis amount of the third lens based on the second radius of curvature include: determining a first vertical coordinate of the second lens in the preset coordinate system based on the first radius of curvature, the curve equation, and a first horizontal coordinate of the first focus of the second lens in the preset coordinate system, and determining the first vertical coordinate as the first off-axis amount of the second lens; and determining a second vertical coordinate of the third lens in the preset coordinate system based on the second radius of curvature, the curve equation, and a second horizontal coordinate of the second focus of the third lens in the preset coordinate system, and determining the second vertical coordinate as the second off-axis amount of the third lens.

7. The spatial beam combining method of a semiconductor laser module according to any one of claims 1 to 6, wherein: After the step of adjusting the second lens and the third lens in the first optical path and the second optical path respectively according to the first adjustment instruction and the second adjustment instruction, the method further includes: The second lens is fine-tuned along the first optical path so that the second lens The output power of the first semiconductor laser chip is coupled to a maximum; The third lens is fine-tuned along the second optical path so that the third lens can couple the output power of the second semiconductor laser chip to a maximum.

8. The spatial beam combining method of a semiconductor laser module according to claim 7, wherein: The second optical path further includes a half-wave plate, and the half-wave plate is located between the reflector and the polarization beam splitter.

9. The spatial beam combining method of a semiconductor laser module according to claim 8, wherein: The third optical path further includes a mode stripper, which is used to couple the third light beam passing through the fourth lens into the optical fiber.

10. The spatial beam combining method of a semiconductor laser module according to claim 9, wherein: The fourth lens is a collimating lens, and the collimating lens is used to converge the third light beam into the stripper.

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