A tunable focusing device and a focusing method for high power semiconductor lasers

Abstract

A kind of tunable focusing device for high-power semiconductor laser, it includes semiconductor laser coupling head, bottom plate, lens lens seat.The semiconductor laser coupling head is coupled with the output fiber of semiconductor laser to ensure laser input, with inlet and outlet, connected with cooling water pipe, to ensure stable operation under high-power condition, the bottom plate includes sliding groove, the width of the lens lens seat and the sliding groove width of the bottom plate are adapted.By passing into cooling water and adjusting the position of lens lens seat, the imaging proportion adjustable output of high-power semiconductor laser can be realized, with good practicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of laser technology, in particular to a tunable focusing device and focusing method for high-power semiconductor laser. BACKGROUND

[0002] Since the first ruby laser was invented, laser technology has made a great progress. As one of the core components of the laser, the choice of pump source directly affects the output power, wavelength and working stability of the laser. Semiconductor laser has the characteristics of small size, low cost and high stability. In recent years, the rapid development of high-power 981nm semiconductor laser and the continuous emergence of various ytterbium-doped laser crystals make semiconductor laser an indispensable pump source in ytterbium-doped laser system.

[0003] However, the current high-power semiconductor laser generally adopts fiber output mode, and its beam quality is easily affected by temperature changes, and lacks effective heat management means, which to some extent limits the full play of its performance. In addition, when semiconductor laser is used as a pump source, it is usually focused by a lens group composed of two lenses to obtain the required size of the pump spot. However, this process requires high precision of the lens position and needs to be finely adjusted to ensure that the ellipticity of the focused spot is close to 1, thereby increasing the time cost of alignment and reducing the production efficiency.

[0004] More importantly, the existing lens group has poor tunability, and when the size of the focused spot needs to be adjusted, tedious adjustment work needs to be performed again, which undoubtedly further increases the operation difficulty and time cost.

[0005] Therefore, in view of the problems existing in the prior art, a new type of pump source or focusing system capable of effectively improving the beam quality, reducing the alignment time cost and enhancing the tunability is needed to meet the urgent needs of ytterbium-doped laser system and other application fields for high-performance pump source. SUMMARY

[0006] The present application proposes a tunable focusing device for high-power semiconductor laser to solve the focusing problem of the output spot of the semiconductor laser.

[0007] The technical solution of the present application is as follows:

[0008] A tunable focusing device for high-power semiconductor laser, characterized in that it comprises a semiconductor laser coupling head, a bottom plate, a lens lens seat, a fiber fixing head and a lens.

[0009] The bottom plate is provided with a sliding groove matched with the lens lens seat, and the sliding groove is provided with a threaded hole.

[0010] The bottom of the lens holder is provided with a sliding opening for fixing with the sliding groove, and the top is provided with a step for increasing the fixing stability.

[0011] The semiconductor laser coupling head is fixed on the bottom plate through screws, and the output optical fiber of the semiconductor laser is connected with the optical fiber fixing head to realize laser input.

[0012] The semiconductor laser coupling head is provided with threaded water inlets and outlets for connecting water pipes for quick insertion and accessing a cooling water system to dissipate heat and ensure the stability of the output spot pattern of the high-power semiconductor laser during operation.

[0013] Further, the width of the sliding groove is equal to the width of the lens holder, and the size of the focused spot is adjusted by the position of the sliding lens holder in the sliding groove, and the height of the lens holder ensures that the center height of the lens is consistent with the output beam height of the semiconductor laser coupling head.

[0014] Further, the lens holder includes a first lens holder and a second lens holder, and the lens includes a first lens and a second lens.

[0015] Further, the lens is a plano-convex lens or a plano-concave lens.

[0016] Further, the flat side of the lens is tightly attached to the step through heat-conducting silicone and fixed on the lens holder to ensure its fixing stability and good heat conduction performance.

[0017] Further, the sliding groove has an array of threaded holes with equal distances in the middle, and the opening size of the sliding opening is equal to the diameter of the threaded holes, so that the size of the focused spot can be easily adjusted by sliding the position of the lens holder, and the height of the lens holder should ensure that the center height of the lens is consistent with the output beam height of the semiconductor laser coupling head.

[0018] Further, the sliding groove is provided with an intelligent indication system, which is combined with the array of threaded holes and the sliding opening, to assist users in quickly and accurately adjusting the position of the lens holder through digital display, thereby improving the adjustment efficiency and accuracy.

[0019] Further, the intelligent indication system integrates a remote control interface, allowing users to remotely monitor and adjust the position of the lens holder through external devices, thereby realizing intelligent control of the size of the focused spot.

[0020] In another aspect, the application also provides a tunable focusing method for a high-power semiconductor laser using the above device, characterized in that it comprises the following steps:

[0021] 1) Fix the semiconductor laser coupling head on the base plate by screwing, connect the output fiber of the semiconductor laser with the fiber fixing head, and thus realize the laser input of the semiconductor laser.

[0022] 2) Connect the water pipe with the water inlet and outlet of the semiconductor laser coupling head, use the corresponding aperture screw to couple the plug thread, and ensure that the cooling water passes in while no water overflows from the plug thread.

[0023] 3) According to the fiber core diameter of the semiconductor laser output fiber, determine the diameter of the focused spot, and then calculate the focal length size of the first lens and the second lens and the position relative to the semiconductor laser output coupling head.

[0024] 4) Place the first lens holder and the second lens holder at the calculated position by using the built-in intelligent indication system through the use of external remote equipment, and then screw through the sliding opening and fix it with the threaded hole on the base plate.

[0025] 5) When the size of the focused spot needs to be changed, repeat steps 3) and 4) through the intelligent indication system monitoring, so as to realize the tunable function of the focused spot.

[0026] Compared with the prior art, the application has the following advantages:

[0027] 1. The threaded water inlet and outlet are provided on the semiconductor laser coupling head, which is used to connect the water pipe for quick insertion into the cooling water system. The corresponding aperture screw is used to couple the plug thread, and a self-locking safety valve can be optionally selected to ensure that no water flows from the plug when cooling water is passed through the water inlet. Not only improves the cooling effect, but also increases the safety of the device, and can ensure the stability of the output spot of the high-power semiconductor laser.

[0028] 2. The size of the focused spot is adjusted by the position of the sliding lens holder in the sliding groove, and the height of the lens holder is designed to ensure that the center height of the lens is consistent with the output beam height of the semiconductor laser coupling head, so that the device reduces the time cost of optical alignment, increases the tunability of the size of the focused spot, can adapt to the needs of different application scenarios, and improves its flexibility and practicality.

[0029] 3. The lens holder is tightly attached to the step through high-performance heat-conducting silicone, which not only ensures high fixing stability, but also provides heat dissipation performance, prolongs the service life of the device, and ensures the stability of the output spot mode in high-power operation state.

[0030] 4. Integrated intelligent indication system, which combines with the array of threaded holes in the sliding groove and the sliding opening of the lens holder, assists users in quickly and accurately adjusting the position of the lens holder through digital display. This intelligent design not only improves the adjustment efficiency and accuracy, but also enables users to more intuitively understand the current position of the lens holder. The intelligent indication system further integrates a remote control interface, allowing users to remotely monitor and adjust the position of the lens holder through external devices, enabling users to intelligently control the size of the focused light spot without direct contact with the device, thereby improving the convenience and safety of operation. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 Structure diagram of the tunable focusing device for high-power semiconductor lasers according to the present application.

[0032] Figure 2 Lens holder 45-degree top view diagram of the tunable focusing device for high-power semiconductor lasers according to the present application.

[0033] Figure 3 Lens holder top view diagram of the tunable focusing device for high-power semiconductor lasers according to the present application.

[0034] Figure 4 Internal waterway diagram of the semiconductor laser coupling head of the tunable focusing device for high-power semiconductor lasers according to the present application.

[0035] In the figure: semiconductor laser coupling head 1, bottom plate 2, lens holder 3, sliding groove 4, optical fiber fixing head 5, water inlet 6, water outlet 7, plug threaded hole 8, threaded hole 9, sliding opening 10, step 11, fixing groove 12, lens 13. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solutions and advantages of the present application clearer and more apparent, the present application will be further described in detail below in conjunction with the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0037] Please refer to Figures 1-4As shown in the figure, a tunable focusing device for high-power semiconductor laser, comprising: a semiconductor laser coupling head 1, both sides of which are provided with fixed grooves 12, the semiconductor laser coupling head 1 is stably and accurately fixed on the base plate 2 through fine adjustment screws, ensuring high-precision alignment of the laser and subsequent optical components; the output fiber of the semiconductor laser is seamlessly connected through a high-precision fiber fixing head 5 to ensure efficient and stable input of laser. The semiconductor laser coupling head 1 is also provided with a water inlet 6 and a water outlet 7. The water inlet 6 and the water outlet 7 are both provided with threads, and the water pipe is coupled with them, and then the water inlet and outlet pipes of the corresponding aperture are connected. The plug screw 8 is coupled with the screw of the corresponding aperture, so as to ensure that when the cooling water is introduced from the water inlet, no water flow will overflow from the plug. The introduction of cooling water can ensure the stability of the output spot pattern under high-power operation. The plug screw 8 can also be equipped with a self-locking safety valve, which automatically closes when the cooling water pressure is abnormal, double-ensuring no water flow overflow, effectively maintaining the stability of the spot pattern during high-power operation.

[0038] Further comprising: a lens holder 3, which is provided with a step 11 inside, the side surface of the lens 13 is closely attached to the lens holder 3 and the step 11 through high-performance heat-conducting silicone respectively, not only ensuring extremely high fixing stability, but also providing excellent heat dissipation performance, effectively prolonging the service life of the device;

[0039] The base plate 2 is provided with a sliding groove 4 of a certain depth, and the middle of the sliding groove 4 has an array of screw holes 9 with equal distances, and the opening size of the sliding opening 10 is equal to the diameter of the screw holes 9. By sliding the position of the lens holder 3, the size of the focused spot can be easily adjusted. The sliding groove 4 on the base plate 2 is also provided with an intelligent indication system, which is combined with the array of screw holes 9 and the sliding opening 10, and through digital display, it helps users to quickly and accurately adjust the position of the lens holder 3, further improving the adjustment efficiency and accuracy.

[0040] According to the high-power semiconductor laser system used, refer to its instruction manual to determine the fiber core diameter and beam quality M 2 of the output fiber. The fiber core diameter is 100 um, and the beam quality M 2For example, if the semiconductor laser with a size of 70.5 needs to focus the light spot to 560 um, through the open source software such as reZonator, the focal length of the first lens is 35 mm, the focal length of the second lens is 100 mm, the distance between the first lens and the semiconductor laser coupling head is 35 mm, the distance between the second lens and the semiconductor laser coupling head is 135 mm, and the distance between the focusing focal point and the semiconductor laser coupling head is 385 mm. Through the digital display, the user can quickly place the lens holder to the corresponding position. Through the precise sliding rail and the sliding groove 4 on the bottom plate 2, combined with the fine positioning of the threaded hole 9 array, the flexible adjustment of the focused light spot size is realized, and the needs of different application scenarios are met.

[0041] Those skilled in the art can easily understand that the above description is only an embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A tunable focusing device for high power semiconductor lasers, characterized in that, The semiconductor laser coupling head (1), the bottom plate (2), the lens seat (3), the optical fiber fixing head (5) and the lens (13) are included. The bottom plate (2) is provided with a sliding groove (4) matched with the lens seat (3), and the sliding groove is provided with a threaded hole (9). The bottom of the lens seat (3) is provided with a sliding opening (10) for fixing the sliding groove (4), and the top is provided with a step (11) for increasing the fixing stability. The semiconductor laser coupling head (1) is provided with a fixed groove (12) on both sides, and the semiconductor laser coupling head (1) is fixed on the bottom plate through a screw, the output optical fiber of the semiconductor laser is connected with the optical fiber fixing head (5), and laser input is realized. The semiconductor laser coupling head (1) is provided with a threaded water inlet (6) and a water outlet (7) for connecting a water pipe quick plug and accessing a cooling water system to dissipate heat and ensure the stability of the output spot mode of the high-power semiconductor laser during operation.

2. The tunable focusing device for high power semiconductor lasers according to claim 1, characterized in that, The width of the sliding groove (4) is equal to the width of the lens seat (3), the size of the focused spot is adjusted by the position of the sliding lens seat (3) in the sliding groove (4), and the height of the lens seat (3) ensures that the center height of the lens is consistent with the output beam height of the semiconductor laser coupling head (1).

3. The tunable focusing device for high power semiconductor lasers according to claim 1, characterized in that, The lens seat (3) includes a first lens seat and a second lens seat, and the lens (13) includes a first lens and a second lens.

4. The tunable focusing device for high power semiconductor lasers according to claim 3, characterized in that, The lens (13) is a plano-convex lens or a plano-concave lens.

5. The tunable focusing device for high power semiconductor lasers according to claim 1, characterized in that, The plane side of the lens (13) is tightly attached to the step (11) and fixed on the lens seat (3) through heat-conducting silicone to ensure its fixing stability and good heat conduction performance.

6. The tunable focusing device for high power semiconductor lasers according to claim 1, characterized in that, The sliding groove (4) has an array of threaded holes (9) with equal distances, the opening size of the sliding opening (10) is equal to the diameter of the threaded holes (9), the size of the focused spot can be easily adjusted by sliding the position of the lens seat (3), and the height of the lens seat (3) should ensure that the center height of the lens (13) is consistent with the output beam height of the semiconductor laser coupling head (1).

7. The tunable focusing device for high power semiconductor lasers according to claim 6, characterized in that The sliding groove (4) is built-in with an intelligent indication system, which is combined with the array of threaded holes (9) and the sliding opening (10) to assist users in quickly and accurately adjusting the position of the lens seat (3) through digital display.

8. The tunable focusing device for high power semiconductor lasers according to claim 7, characterized in that, The intelligent indication system integrates a remote control interface, allowing users to remotely monitor and adjust the position of the lens seat (3) through external devices, realizing intelligent control of the size of the focused spot.

9. A focusing method using the tunable focusing device for high power semiconductor lasers according to any one of claims 1 to 8, characterized in that, The method comprises the following steps: 1) Fix the semiconductor laser coupling head on the bottom plate, and connect the output optical fiber of the semiconductor laser with the optical fiber fixing head; 2) Connect the water pipe to the water inlet and water outlet of the semiconductor laser coupling head, and couple the plug thread with the screw of the corresponding aperture to ensure that the cooling water flows in without overflowing from the plug thread. 3) Determine the diameter of the focused spot according to the fiber core diameter and fiber quality of the fiber output from the semiconductor laser, and then calculate the focal length of the first lens and the second lens and their positions relative to the output coupling head of the semiconductor laser; 4) Place the lens holder at the calculated position by using the built-in intelligent indication system, and fix it to the threaded hole on the bottom plate through the screw passing through the sliding opening; 5) When the size of the focused spot needs to be changed, repeat steps 3) and 4) through the intelligent indication system monitoring, so as to realize the tunable function of the focused spot.

10. The focusing method of the tunable focusing device for high-power semiconductor lasers according to claim 9, characterized in that, In step 3), open source software is used to calculate the focal length and position of the lens.

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