Spatial beam combining method for semiconductor laser modules

Abstract

The embodiment of the application discloses a spatial beam combining method of a semiconductor laser module, comprising the following steps: acquiring a first curvature radius of a second lens and a second curvature radius of a third lens, determining a first adjusting instruction and a second adjusting instruction, adjusting the second lens and the third lens according to the first adjusting instruction and the second adjusting instruction, controlling a first light beam emitted by a first semiconductor laser chip to enter a polarization beam splitter via the first lens and the adjusted second lens, controlling a second light beam emitted by a second semiconductor laser chip to enter the polarization beam splitter via the first lens, the adjusted third lens and a mirror in sequence, combining the first light beam and the second light beam into a third light path by the polarization beam splitter to form a third light beam, and making the third light beam enter an optical fiber via a fourth lens. By using the application, the output power of the semiconductor laser module can be increased without changing the size of the semiconductor laser module.

Description

Technical Field

[0001] This application relates to the field of optical technology, specifically to a spatial beam combining method for a semiconductor laser module. Background Technology

[0002] Semiconductor lasers are increasingly used in communications, military, and medical fields. As a type of semiconductor component, the market demand for semiconductor lasers is constantly increasing. In recent years, high-power, high-beam-quality semiconductor lasers have experienced rapid development.

[0003] In related technologies, the spatial beam combining method for semiconductor laser modules involves fusing the light output from multiple semiconductor lasers with a fiber-coupled semiconductor laser module, and arranging multiple semiconductor lasers side-by-side inside the housing of the semiconductor laser module. To increase the output power, one can either increase the number of semiconductor lasers or increase the output power of a single semiconductor laser.

[0004] However, methods such as increasing the number of semiconductor lasers in a semiconductor laser module or increasing the output power of a single semiconductor laser are 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 its size is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] This application provides a spatial beam combining method for a semiconductor laser module to solve the technical problem that the output power of a semiconductor laser module cannot be increased without changing the overall space of the semiconductor laser module.

[0006] In one respect, to solve the above-mentioned technical problems, this application provides a spatial beam combining method for a semiconductor laser module. The semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. Along the first optical path, a first semiconductor laser chip, a first lens, and a second lens are sequentially arranged. Along the second optical path, a second semiconductor laser chip, the first lens, the third lens, and a reflector are sequentially arranged. Along the third optical path, a polarizing beam splitter and a fourth lens are sequentially arranged. The spatial beam combining method for the semiconductor laser module includes the following steps:

[0007] Obtain the first radius of curvature of the vertex of the aspherical curve where the second lens is located, and the second radius of curvature of the vertex of the aspherical curve where the third lens is located;

[0008] A first adjustment command for the second lens in the first optical path is determined based on the first radius of curvature, and a second adjustment command for the third lens in the second optical path is determined based on the second radius of curvature.

[0009] According to the first adjustment command and the second adjustment command, the second lens and the third lens are adjusted in the first optical path and the second optical path respectively;

[0010] The first beam emitted by the first semiconductor laser chip is controlled to pass through the first lens and the adjusted second lens to the polarizing beam splitter. The second beam emitted by the second semiconductor laser chip is controlled to pass through the first lens, the adjusted third lens, and the reflector to the polarizing beam splitter. The polarizing beam splitter combines the first beam and the second beam into the third optical path to form a third beam, and the third beam is coupled into the optical fiber through the fourth lens.

[0011] In this embodiment of the invention, the second lens and the third lens are collimating and reflecting lenses.

[0012] In this embodiment of the invention, the collimating and reflecting integrated lens is an off-axis parabolic lens.

[0013] In this embodiment of the invention, the step of determining a first adjustment command for the second lens in the first optical path based on the first radius of curvature, and determining a second adjustment command for the third lens in the second optical path based on the second radius of curvature, includes:

[0014] The first off-axis amount of the second lens is determined based on the first radius of curvature, and the second off-axis amount of the third lens is determined based on the second radius of curvature.

[0015] Based on the first off-axis amount, a first adjustment command is determined for the second lens in the first optical path, and based on the second off-axis amount, a second adjustment command is determined for the third lens in the second optical path.

[0016] In this embodiment of the invention, before 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, the method further includes:

[0017] Determine the aspherical curves corresponding to the second lens and the third lens;

[0018] When the aspherical curve is a parabolic curve, determine the equation of the parabolic curve;

[0019] The equation of the curve includes: z 2 =2x / c;

[0020] Wherein, x and z are the horizontal and vertical coordinates of the parabolic curve in the preset coordinate system, respectively, and c is the reciprocal of the radius of curvature of the vertex of the parabolic curve.

[0021] In this embodiment of the invention, the step 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, includes:

[0022] Based on the first radius of curvature, the curve equation, and the first abscissa of the first focal point of the second lens in the preset coordinate system, the first ordinate of the second lens in the preset coordinate system is determined, and the first ordinate is determined as the first off-axis amount of the second lens.

[0023] Based on the second radius of curvature, the curve equation, and the second abscissa of the second focal point of the third lens in the preset coordinate system, the second ordinate of the third lens in the preset coordinate system is determined, and the second ordinate is determined as the second off-axis amount of the third lens.

[0024] In this embodiment of the invention, 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 command and the second adjustment command, the method further includes:

[0025] The second lens is finely adjusted along the first optical path direction so that the second lens couples the output power of the first semiconductor laser chip to the maximum.

[0026] The third lens is finely adjusted along the second optical path direction so that the third lens couples the output power of the second semiconductor laser chip to the maximum.

[0027] In this embodiment of the invention, the second optical path further includes a half-wave plate, which is located between the reflecting mirror and the polarizing beam splitter.

[0028] In this embodiment of the invention, the third optical path further includes a mode stripper, which is used to couple the third beam through the fourth lens into the optical fiber.

[0029] In this embodiment of the invention, the fourth lens is a collimating lens, which is used to converge the third beam into the mold stripper.

[0030] This application provides a spatial beam combining method for a semiconductor laser module. By obtaining the first radius of curvature of the second lens and the second radius of curvature of the third lens in the semiconductor laser module, a first adjustment command and a second adjustment command are determined. The second and third lenses can then be adjusted according to the first and second adjustment commands. Furthermore, the first beam emitted by the first semiconductor laser chip can be controlled to pass through the first lens and the adjusted second lens to a polarizing beam splitter. The second beam emitted by the second semiconductor laser chip can be controlled to pass through the first lens, the adjusted third lens, and a reflector to a polarizing beam splitter. The polarizing beam splitter combines the first and second beams into a third optical path to form a third beam, which 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 its size. Attached Figure Description

[0031] 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.

[0032] Figure 1 This is a schematic flowchart of a spatial beam combining method for a semiconductor laser module provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of a semiconductor laser module provided in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of a semiconductor laser module provided in related technologies;

[0035] Figure 4 This is a schematic diagram of the reflection principle of an off-axis parabolic lens provided in an embodiment of the present invention;

[0036] Figure 5 This is a schematic diagram of solving the off-axis amount using the curve equation provided in an embodiment of the present invention;

[0037] Figure 6 This is a schematic diagram of a single-channel collimated spot of a semiconductor laser module provided in an embodiment of the present invention;

[0038] Figure 7 This is a schematic diagram of a single-channel collimated beam of a semiconductor laser module provided in related technologies;

[0039] The reference numerals in the accompanying drawings are as follows:

[0040] 10. First semiconductor laser chip; 11. Second semiconductor laser chip; 12. First lens; 13. Second lens; 14. Third lens; 15. Mirror; 16. Half-wave plate; 17. Polarizing beam splitter; 18. Fourth lens; 19. Mode stripper; 20. Optical fiber;

[0041] 131. Slow-axis collimating lens; 132. Small reflecting mirror. Detailed Implementation

[0042] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0043] In the description of this application, it should be understood that the terms "longitudinal," "lateral," "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," and "horizontal," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified. In this application, " / " means "or."

[0044] Reference numbers and / or reference letters may be repeated in different examples in this application. Such repetition is for the purpose of simplification and clarity and does not in itself indicate the relationship between the various implementations and / or settings discussed.

[0045] In this embodiment of the invention, semiconductor lasers are becoming increasingly widely used in fields such as communications, military, and medicine. As a semiconductor component, the market demand for semiconductor lasers is constantly increasing. In recent years, high-power, high-beam-quality semiconductor lasers have experienced rapid development.

[0046] In related technologies, the spatial beam combining method for semiconductor laser modules involves fusing the light output from multiple semiconductor lasers with a fiber-coupled semiconductor laser module, and arranging multiple semiconductor lasers side-by-side inside the housing of the semiconductor laser module. To increase the output power, one can either increase the number of semiconductor lasers or increase the output power of a single semiconductor laser.

[0047] However, methods such as increasing the number of semiconductor lasers in a semiconductor laser module or increasing the output power of a single semiconductor laser are limited by the overall space of the semiconductor laser module, thus affecting the maximum output power.

[0048] Therefore, how to increase the output power of a semiconductor laser module without changing its size is a technical problem that urgently needs to be solved.

[0049] To resolve the above technical issues, please refer to [link / reference]. Figure 1 and Figure 2 , Figure 1 This is a schematic flowchart of a spatial beam combining method for a semiconductor laser module provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of a semiconductor laser module provided in an embodiment of the present invention. Specifically, as shown... Figure 1 and Figure 2 As shown, this application provides a spatial beam combining method for a semiconductor laser module. The semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. Along the first optical path, a first semiconductor laser chip 10, a first lens 12, and a second lens 13 are sequentially arranged. Along the second optical path, a second semiconductor laser chip 11, the first lens 12, a third lens 14, and a reflector 15 are sequentially arranged. Along the third optical path, a polarizing beam splitter 17 and a fourth lens 18 are sequentially arranged. Optionally, 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.

[0050] Specifically, the spatial beam combining method for the semiconductor laser module provided in this embodiment includes steps 101 to 104;

[0051] Step 101: Obtain the first radius of curvature of the vertex of the aspherical curve where the second lens is located, and the second radius of curvature of the vertex of the aspherical curve where the third lens is located.

[0052] In this embodiment, the positions of the second and third lenses in the semiconductor laser module provided in this embodiment are not determined. Therefore, it is necessary to determine the specific positions of the second and third lenses in the semiconductor laser module and deploy them so as to achieve the purpose of spatial beam combining of the laser emitted by the semiconductor laser chip in the semiconductor laser module.

[0053] Specifically, in differential geometry, the reciprocal of curvature is the radius of curvature. The curvature of a plane curve is the rate of rotation of the tangent direction angle about a point on the curve with respect to the arc length. It is defined by differentiation to indicate the degree to which the curve deviates from a straight line. Thus, in this embodiment, the first radius of curvature of the vertex of the aspherical curve where the second lens is located and the second radius of curvature of the vertex of the aspherical curve where the third lens is located can be determined by calculation using differential geometry.

[0054] Step 102: Determine a first adjustment command for the second lens in the first optical path based on the first radius of curvature, and determine a second adjustment command for the third lens in the second optical path based on the second radius of curvature.

[0055] Please refer to the relevant technologies. Figure 3 , Figure 3 This is a schematic diagram of a semiconductor laser module provided in related technologies, such as... Figure 3 As shown, the semiconductor laser module in the related technology 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 arranged in sequence. 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 arranged in sequence. Along the third optical path, a polarizing beam splitter and a fourth lens are arranged in sequence.

[0056] Simultaneously refer to Figure 2 and Figure 3As can be seen, the semiconductor laser module provided in this embodiment has a second lens and a third lens respectively set in the first and second optical paths, while the semiconductor laser modules in related technologies have a slow-axis collimating lens and a small reflecting mirror respectively set in the first and second optical paths. Therefore, with the overall spatial size of the semiconductor laser module remaining unchanged, the space occupied by the structural deployment scheme within the semiconductor laser module provided in this embodiment is smaller than that occupied by the structural deployment scheme within the semiconductor laser module in related technologies. That is, the semiconductor laser module provided in this embodiment has remaining expansion space. Therefore, the semiconductor laser module provided in this embodiment can increase the overall output power of the semiconductor laser module with the same spatial size by increasing the number of semiconductor laser chips or increasing the output power of a single semiconductor laser chip, thereby solving the technical problems existing in related technologies.

[0057] In order to reduce the space occupied by the structural deployment scheme within the semiconductor laser module, the second and third lenses provided in this embodiment need to have the functions of the slow-axis collimating lens and small reflector in the semiconductor laser module provided in the related art. Therefore, the second and third lenses provided in this embodiment can be integrated collimating and reflecting lenses, thereby achieving the purpose of replacing the slow-axis collimating lens and small reflector.

[0058] In some embodiments, the collimating and reflecting integrated lens provided in this embodiment can be an off-axis parabolic lens. For details, please refer to [link to relevant documentation]. Figure 4 , Figure 4 This is a schematic diagram illustrating the reflection principle of an off-axis parabolic lens provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the off-axis parabolic lens provided in this embodiment can focus a parallel incident light beam to the 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 small reflector in the semiconductor laser module provided in the related technology.

[0059] In this embodiment, the present invention converts transmission collimation into reflection cylindrical collimation, and the reflector adopts an off-axis parabolic surface. Compared with the transmission collimation used in related technologies, this embodiment can achieve smaller beam aberrations and smaller size when folding and shaping the beam, thereby reducing the overall width and volume of the semiconductor laser module.

[0060] However, after determining that off-axis parabolic lenses should be used to replace the slow-axis collimating lens and small reflector in the related technology, it is also necessary to determine the deployment position of off-axis parabolic lenses (i.e., the second and third lenses) in the semiconductor laser module so that the incident beam can be reflected to the polarizing beam splitter, so that the beams incident on the first and second optical paths can be polarized and combined by the polarizing beam splitter.

[0061] Therefore, after determining the first radius of curvature of the aspherical curve vertex where the second lens is located, and the second radius of curvature of the aspherical curve vertex where the third lens is located, this embodiment can determine the specific positions of the second and third lenses in the semiconductor laser module based on the radius of curvature and the focal positions of the second and third lenses. Then, based on the initial positions of the second and third lenses and the specific positions, a first adjustment command that needs to be adjusted for the second lens in the first optical path and a second adjustment command that needs to be adjusted for the third lens in the second optical path can be determined.

[0062] As an optional embodiment, the steps of determining the first adjustment command for the second lens in the first optical path based on the first radius of curvature and determining the second adjustment command for the third lens in the second optical path based on the second radius of curvature can specifically be: 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; determining the first adjustment command for the second lens in the first optical path based on the first off-axis amount and determining the second adjustment command for the third lens in the second optical path based on the second off-axis amount.

[0063] In this embodiment, both the second and third lenses provided are off-axis parabolic lenses. Therefore, this embodiment can determine the first off-axis amount of the second lens and the second off-axis amount of the third lens based on the corresponding radii of curvature of the second and third lenses. The first and second off-axis amounts are the distances between the second and third lenses and their corresponding focal points. Therefore, based on the first and second off-axis amounts, the first adjustment command and the second adjustment command for adjusting the second and third lenses can be determined.

[0064] As an optional embodiment, this embodiment can limit the aspherical curves corresponding to the second lens and the third lens to a pre-set coordinate system, so that the actual off-axis amount of the second lens and the third lens can be solved by the specific coordinate values ​​in the coordinate system.

[0065] Specifically, by substituting the off-axis parabolic lens at different positions in a preset coordinate system, and using a beam parallel to the horizontal axis as the incident beam of the off-axis parabolic lens, the focal position of the off-axis parabolic lens can be determined in this 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 aspherical curve on which the off-axis parabolic lens is located can be derived. This curve equation can be:

[0066]

[0067] Where z is the ordinate of the point on the aspherical curve where the off-axis parabolic lens is located in the preset coordinate system, x is the abscissa of the point on the aspherical curve where the off-axis parabolic lens is located in the preset coordinate system, c is the curvature of the vertex of the aspherical curve where the off-axis parabolic lens is located, which is the reciprocal of the radius of curvature of the vertex of the aspherical curve, k is the conic coefficient, and α is the aspherical coefficient.

[0068] Since the off-axis amount of the parabolic lens can be determined when the focal point of the aspherical curve is located at the position of the radius of curvature of the vertex of the aspherical curve at half the horizontal axis, the off-axis amount of the parabolic lens can be obtained by substituting the radius of curvature of the vertex of the aspherical curve at half the horizontal axis as the horizontal coordinate value into the curve equation. Specifically, the off-axis amount is equal to the radius of curvature of the vertex of the aspherical curve.

[0069] Thus, by using the method provided in the above embodiments, the first off-axis amount and the second off-axis amount corresponding to the second lens and the third lens can be determined respectively. Then, based on the first off-axis amount and the second off-axis amount, the first adjustment command and the second adjustment command for adjusting the second lens and the third lens can be determined, so as to adjust the position of the second lens and the third lens in the semiconductor laser module. This allows the purpose of polarization beam combining of the two optical paths to be achieved after the semiconductor laser module is powered on.

[0070] In some embodiments, the curve equations provided above are applicable to calculating the off-axis amount of all off-axis parabolic lenses. However, when the aspherical curve corresponding to the off-axis parabolic lens is a parabolic curve, the conic coefficient k = -1 and the aspherical coefficient α = 0 can be determined, thereby simplifying the above curve equations and obtaining the simplified curve equations as follows:

[0071]

[0072] For details, please see Figure 5 , Figure 5This is a schematic diagram of solving the off-axis amount using the curve equation provided in an embodiment of the present invention, where x and z are the horizontal and vertical coordinates of the parabolic curve in a preset coordinate system, c is the reciprocal of the radius of curvature of the vertex of the parabolic curve, d is the distance from the focal point 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.

[0073] Therefore, prior to 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, the spatial beam combining method for the semiconductor laser module provided in this embodiment may further include: determining the aspherical curves corresponding to the second lens and the third lens; and, if the aspherical curve is a parabolic curve, determining the curve equation of the parabolic curve; the curve equation includes: z 2 = 2x / c.

[0074] Then, based on this simplified curve equation, the off-axis amount of the off-axis parabolic lens can be quickly solved. Specifically, the steps provided in this embodiment for 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, can be as follows: Based on the first radius of curvature, the curve equation, and the first abscissa of the first focal point of the second lens in the preset coordinate system, determine the first ordinate of the second lens in the preset coordinate system, and determine the first ordinate as the first off-axis amount of the second lens; based on the second radius of curvature, the curve equation, and the second abscissa of the second focal point of the third lens in the preset coordinate system, determine the second ordinate of the third lens in the preset coordinate system, and determine the second ordinate as the second off-axis amount of the third lens.

[0075] After determining the first off-axis amount of the second lens and the second off-axis amount of the third lens, the first adjustment command and the second adjustment command for adjusting the second lens and the third lens can be determined.

[0076] 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 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 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.

[0077] 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 command and the second adjustment command.

[0078] In this embodiment, the first adjustment command and the second adjustment command provided 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 beam and the second beam to the polarization beam splitter, thereby the first beam and the second beam can be polarized and combined by the polarization beam splitter to enhance the output power of the semiconductor laser module.

[0079] In this embodiment, please refer to Figure 6 and Figure 7 , Figure 6 This is a schematic diagram of a single-path collimated beam of a semiconductor laser module provided in an embodiment of the present invention. Figure 7 This is a schematic diagram of a single-path collimated beam spot of a semiconductor laser module provided in related technologies. Figure 6 and Figure 7 It can be seen that the single-path collimated spot of the semiconductor laser module provided in this embodiment is almost the same as that of the semiconductor laser module provided in related technologies. That is, by using the semiconductor laser module with relatively fewer devices provided in this embodiment, the same effect can be achieved as that of the semiconductor laser module with relatively more devices provided in related technologies.

[0080] As an optional embodiment, to further improve the output power of the semiconductor laser module, this embodiment also requires fine-tuning the second lens and the third lens to maximize the coupling of the output power of the first semiconductor laser chip and the second semiconductor laser chip. Specifically, 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 command and the second adjustment command, the spatial beam combining method of the semiconductor laser module provided in this embodiment may further include: fine-tuning the second lens along the first optical path direction so that the second lens couples the output power of the first semiconductor laser chip to the maximum; and fine-tuning the third lens along the second optical path direction so that the third lens couples the output power of the second semiconductor laser chip to the maximum.

[0081] Step 104: Control the first beam emitted by the first semiconductor laser chip to pass through the first lens and the adjusted second lens to the polarizing beam splitter. Control the second beam emitted by the second semiconductor laser chip to pass through the first lens, the adjusted third lens, and the reflector to the polarizing beam splitter in sequence. The polarizing beam splitter will polarize and combine the first beam and the second beam into the third optical path to form a third beam. The third beam will then be coupled into the optical fiber through the fourth lens.

[0082] After adjusting and fine-tuning the second and third lenses in the semiconductor laser module, the semiconductor laser module can be powered on, and the first and second beams emitted by the first and second semiconductor laser chips can be controlled so that the first and second beams are ultimately polarized and combined through the polarization beam splitter, and finally coupled into the light, thereby increasing the output power of the semiconductor laser module.

[0083] In some embodiments, please continue to see Figure 2 In this embodiment, the second optical path of the semiconductor laser module may further include a half-wave plate 16, located between the reflecting mirror 15 and the polarizing beam splitter 17; the third optical path may further include a mode stripper 19, which couples the third beam transmitted 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 focuses the third beam into the mode stripper 19.

[0084] To better illustrate the spatial beam combining method for the semiconductor laser module provided in this embodiment of the invention, please refer to [link / reference]. Figure 2 This embodiment will be described with a specific example: First, the first beam emitted from the first semiconductor laser chip is collimated along its fast axis by a first lens, and then collimated along its slow axis by a second lens, and deflected. After collimation by the first and second lenses, the first beam is emitted as parallel light and converges onto the beam quality analyzer via a focusing tube. The centroid coordinates and width reference standard are used; this width needs to be adjusted along the first optical path using the second lens to reach the minimum beam width. At this point, the second lens position serves as a coarse positioning position and also as a reference position for the coupling of the first lens in the remaining path. After baking, the changes in centroid coordinates and width must be kept within a certain range.

[0085] Next, a stripper is directly installed on the base plate, and reverse light transmission is performed at one end of the optical fiber. After collimation by the collimator, the beam is focused onto the beam quality analyzer via a focusing tube, with the centroid coordinates referenced to a standard component. Then, following the same procedure, the second semiconductor laser chip and the third lens in the second optical path are adjusted. A mirror is used to guide the second beam in the second optical path and the first beam in the first optical path to a polarizing beam splitter, which then polarizes and combines the beams into the third optical path to form the third beam. At this point, the initial positions of the second and third lenses are determined.

[0086] Then, fine-tune the power coupling of the second and third lenses to maximize the power. Record the positions of the second and third lenses, and fine-tune their positions again along their respective optical path directions, while maximizing the power coupling, until the power decreases when the second and third lenses are adjusted back and forth. At this point, the positions of the second and third lenses are the power peak positions, which are the precise positions that the second and third lenses need to be positioned.

[0087] Finally, the semiconductor laser module is deployed according to the precise positions of the second and third lenses and the positions of the remaining components. After deployment, the semiconductor laser module is powered on to achieve spatial beam combining of the semiconductor laser module.

[0088] This concludes the detailed explanation of the spatial beam combining method for semiconductor laser modules.

[0089] In summary, this invention provides a spatial beam combining method for a semiconductor laser module. The semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. Along the first optical path, a first semiconductor laser chip, a first lens, and a second lens are sequentially arranged. Along the second optical path, a second semiconductor laser chip, a first lens, a third lens, and a reflector are sequentially arranged. Along the third optical path, a polarizing beam splitter and a fourth lens are sequentially arranged. The spatial beam combining method for the semiconductor laser module includes the following steps: obtaining the first radius of curvature of the aspherical curve vertex where the second lens is located, and the second radius of curvature of the aspherical curve vertex where the third lens is located, and then, according to the first... A first adjustment command for the second lens in the first optical path is determined by a radius of curvature, and a second adjustment command for the third lens in the second optical path is determined by a second radius of curvature. Based on the first and second adjustment commands, the second and third lenses are adjusted in the first and second optical paths respectively. This controls the first beam emitted by the first semiconductor laser chip to pass through the first lens and the adjusted second lens to the polarizing beam splitter. Similarly, the second beam emitted by the second semiconductor laser chip passes through the first lens, the adjusted third lens, and a reflector to the polarizing beam splitter. The polarizing beam splitter then combines the first and second beams into the third optical path to form a third beam, which is then coupled into the optical fiber via a fourth lens. Using this embodiment of the invention, the output power of the semiconductor laser module can be increased without changing its size.

[0090] 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 referred to each other.

[0091] The above are merely specific embodiments of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily 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 invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A spatial beam combining method for a semiconductor laser module, characterized in that, The semiconductor laser module includes a first optical path, at least one second optical path, and a third optical path. Along the first optical path, a first semiconductor laser chip, a first lens, and a second lens are sequentially arranged. Along the second optical path, a second semiconductor laser chip, the first lens, the third lens, and a reflector are sequentially arranged. Along the third optical path, a polarizing beam splitter and a fourth lens are sequentially arranged. The spatial beam combining method of the semiconductor laser module includes the following steps: Obtain the first radius of curvature of the vertex of the aspherical curve where the second lens is located, and the second radius of curvature of the vertex of the aspherical curve where the third lens is located; Determine the aspherical curves corresponding to the second lens and the third lens; When the aspherical curve is a parabolic curve, determine the equation of the parabolic curve; The equation of the curve includes: ; Wherein, x and z are the horizontal and vertical coordinates of the parabolic curve in the preset coordinate system, respectively, and c is the reciprocal of the radius of curvature of the vertex of the parabolic curve; The first off-axis amount of the second lens is determined based on the first radius of curvature, and the second off-axis amount of the third lens is determined based on the second radius of curvature. Based on the first off-axis amount, a first adjustment command is determined for the second lens in the first optical path, and the first off-axis amount is determined for the first spot range of the first beam emitted by the first semiconductor laser chip on the second lens. Based on the second off-axis amount, a second adjustment command is determined for the third lens in the second optical path, and the second off-axis amount is determined for the second spot range of the second beam emitted by the second semiconductor laser chip on the third lens. According to the first adjustment command and the second adjustment command, the positions of the second lens and the third lens are adjusted in the first optical path and the second optical path respectively, and the mirror size of the second lens and the third lens is adjusted according to the first light spot range and the second light spot range, so that the mirror size of the second lens and the third lens is larger than the first light spot range and the second light spot range respectively; The first beam is controlled to pass through the first lens and the adjusted second lens to the polarizing beam splitter. The second beam is controlled to pass through the first lens, the adjusted third lens, and the reflector to the polarizing beam splitter. The polarizing beam splitter combines the first beam and the second beam into the third optical path to form a third beam. The third beam is then coupled into the optical fiber through the fourth lens.

2. The spatial beam combining method for a semiconductor laser module according to claim 1, characterized in that, The second lens and the third lens are integrated collimating and reflecting lenses.

3. The spatial beam combining method for a semiconductor laser module according to claim 2, characterized in that, The collimating and reflecting integrated lens is an off-axis parabolic lens.

4. The spatial beam combining method for a semiconductor laser module according to claim 1, characterized in that, 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, include: Based on the first radius of curvature, the curve equation, and the first abscissa of the first focal point of the second lens in the preset coordinate system, the first ordinate of the second lens in the preset coordinate system is determined, and the first ordinate is determined as the first off-axis amount of the second lens. Based on the second radius of curvature, the curve equation, and the second abscissa of the second focal point of the third lens in the preset coordinate system, the second ordinate of the third lens in the preset coordinate system is determined, and the second ordinate is determined as the second off-axis amount of the third lens.

5. The spatial beam combining method for a semiconductor laser module according to any one of claims 1-4, characterized in that, 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 command and the second adjustment command, the method further includes: The second lens is finely adjusted along the first optical path direction so that the second lens couples the output power of the first semiconductor laser chip to the maximum. The third lens is finely adjusted along the second optical path direction so that the third lens couples the output power of the second semiconductor laser chip to the maximum.

6. The spatial beam combining method for a semiconductor laser module according to claim 5, characterized in that, The second optical path also includes a half-wave plate, which is located between the reflecting mirror and the polarizing beam splitter.

7. The spatial beam combining method for a semiconductor laser module according to claim 6, characterized in that, The third optical path also includes a mode stripper for coupling the third beam through the fourth lens into the optical fiber.

8. The spatial beam combining method for a semiconductor laser module according to claim 7, characterized in that, The fourth lens is a collimating lens, which is used to converge the third beam into the mold stripper.

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